liston catch - Page 53 - Developer IT

Sniffer for certain port

- by Costa

Hi I need a sniffer to catch all http communications on certain port, recommend one for me! thanks

Should I use multiple threads in this situation? [Ruby]

I'm opening multiple files and processing them, one line at a time. The files contain tokens separating the data, such that sometimes the processing of one file may have to wait for others to catch up to that same token. I was doing this initially with only one thread and an array indicating with true/false if the file should be read in the current iteration or if it should wait for some of the others to catch up. Would using threads make this simpler? More efficient? Does Ruby have a mechanism for this?

Read the article

Send a String[] ArrayList over Socket connection

- by Duncan Palmer

So i'm trying to send a String[] Array/List over an open socket connection. I currently have this code: Sending: public void sendData() { try { OutputStream socketStream = socket.getOutputStream(); ObjectOutputStream objectOutput = new ObjectOutputStream(socketStream); objectOutput.writeObject(new String[] {"Test", "Test2", "Test3"}); objectOutput.close(); socketStream.close(); } catch (Exception e) { System.out.println(e.toString()); } } Recieving: public Object readData() { try { InputStream socketStream = socket.getInputStream(); ObjectInputStream objectInput = new ObjectInputStream(new GZIPInputStream(socketStream)); Object a = objectInput.readObject(); return a; } catch(Exception e) { return null; } } After I have recieved the String array/list on the other end I want to be able to iterate through it like I would do normally so I can get the values. My current code doesn't seem to works as it returns null as the value. is this possible?

Read the article

How to read output of android process command

- by kevdliu

I am trying to get the output of android shell command 'getprop' with java since getprop() always returns null no matter what. I tried this from developer.android.com: Process process = null; try { process = new ProcessBuilder() .command("/system/bin/getprop", "build.version") .redirectErrorStream(true) .start(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } InputStream in = process.getInputStream(); //String prop = in.toString(); System.out.println(in); process.destroy(); However what is printed is not the output but a bunch of characters and numbers (dont have the exact output right now). How can i get the output of the process? Thanks!

Read the article

TPageControl tab area OnMouseEnter OnMouseLeave events

- by daemon_x

Hello, I need to catch the "OnMouseEnter" and "0nMouseLeave" for a certain area of the TPageControl component. With that specific area I mean the whole "tab header" rectangle. The problem is, that the page control doesn't catch the messages (I'm catching internal control messages CM_MOUSEENTER and CM_MOUSELEAVE) in the "empty" space. The aim for me is to draw a small arrow in the right empty side when user hovers in the red framed area (and drawing is just piece of cake) and erase it when leaves this area. And I'm don't care about the overflow of the tabs (which causes to draw scrolling double button) - that will never happen.

Read the article

UnknownHostException in java (that too only sometimes)

- by Nitesh Panchal

Hello, I am trying to read rss feed of Yahoo but i am unable to make it work properly. The code is absolutely correct , i am sure about it. It works sometimes but sometimes i get UnknownHostException. What can be the reason? Is there some problem with my internet or something else? This is my code :- public List<RssFeed> getRssFeed() { try { List<RssFeed> objList = new ArrayList<RssFeed>(); DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); DocumentBuilder db = dbf.newDocumentBuilder(); Document doc = db.parse("http://rss.news.yahoo.com/rss/india"); //doc.getDocumentElement().normalize(); Element docElement = doc.getDocumentElement(); NodeList objChannelList = docElement.getChildNodes(); for (int intIndex = 0; intIndex < objChannelList.getLength(); intIndex++) { if (objChannelList.item(intIndex).getNodeType() == Node.ELEMENT_NODE) { Element elemItem = (Element) objChannelList.item(intIndex); NodeList itemList = elemItem.getElementsByTagName("item"); //show only 3 news int count = itemList.getLength() > 3 ? 3 : objChannelList.getLength(); for (int intSubIndex = 0; intSubIndex < count; intSubIndex++) { NodeList itemDetailList = itemList.item(intSubIndex).getChildNodes(); String strTitle = ((Node) itemDetailList.item(RSS_VALUES.TITLE.getValue())).getFirstChild().getNodeValue(); String strdescription = ((Node) itemDetailList.item(RSS_VALUES.DESCRIPTION.getValue())).getFirstChild().getNodeValue(); String strLink = ((Node) itemDetailList.item(RSS_VALUES.LINK.getValue())).getFirstChild().getNodeValue(); //System.out.println(strTitle + "\n" + strdescription + "\n" + strLink + "\n\n\n\n"); objList.add(new RssFeed(strTitle, strdescription, strLink)); } } } return objList; } catch (SAXException ex) { Logger.getLogger(Utils.class.getName()).log(Level.SEVERE, null, ex); } catch (IOException ex) { Logger.getLogger(Utils.class.getName()).log(Level.SEVERE, null, ex); } catch (ParserConfigurationException ex) { Logger.getLogger(Utils.class.getName()).log(Level.SEVERE, null, ex); } return null; } Thanks in advance :). This problem has been bugging me since 1 month. Don't know why does Java in this case behave as per its mood :(

Read the article

c# xml function to check whether a string is equal to a xml attribute, to add selected combobox item

- by fuch

i want to check the combobox.selecteditem.tostring() on combobox select in a given xml with several nodes, where each one has an attribute called "name" private void comboBox1_SelectedIndexChanged(object sender, EventArgs e) { try { textBox1.AppendText(nameAttributeCheck(comboBox1.SelectedItem.ToString())); } catch { } } private string nameAttributeCheck(string a) { XmlDocument doc = new XmlDocument(); doc.Load("armor.xml"); XmlElement root = doc.DocumentElement; XmlNodeList items = root.SelectNodes("/items"); String result = null; try { foreach (XmlNode item in items) { if (string.Equals(a, item.Attributes["name"].InnerText.ToString())) { result += item.Attributes["picture"].InnerText.ToString(); } } } catch { } return result; } each time i try it, nothing happens

Read the article

Java looping through array - Optimization

- by oudouz

I've got some Java code that runs quite the expected way, but it's taking some amount of time -some seconds- even if the job is just looping through an array. The input file is a Fasta file as shown in the image below. The file I'm using is 2.9Mo, and there are some other Fasta file that can take up to 20Mo. And in the code im trying to loop through it by bunches of threes, e.g: AGC TTT TCA ... etc The code has no functional sens for now but what I want is to append each Amino Acid to it's equivalent bunch of Bases. Example : AGC - Ser / CUG Leu / ... etc So what's wrong with the code ? and Is there any way to do it better ? Any optimization ? Looping through the whole String is taking some time, maybe just seconds, but need to find a better way to do it. import java.io.BufferedReader; import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; public class fasta { public static void main(String[] args) throws IOException { File fastaFile; FileReader fastaReader; BufferedReader fastaBuffer = null; StringBuilder fastaString = new StringBuilder(); try { fastaFile = new File("res/NC_017108.fna"); fastaReader = new FileReader(fastaFile); fastaBuffer = new BufferedReader(fastaReader); String fastaDescription = fastaBuffer.readLine(); String line = fastaBuffer.readLine(); while (line != null) { fastaString.append(line); line = fastaBuffer.readLine(); } System.out.println(fastaDescription); System.out.println(); String currentFastaAcid; for (int i = 0; i < fastaString.length(); i+=3) { currentFastaAcid = fastaString.toString().substring(i, i + 3); System.out.println(currentFastaAcid); } } catch (NullPointerException e) { System.out.println(e.getMessage()); } catch (FileNotFoundException e) { System.out.println(e.getMessage()); } catch (IOException e) { System.out.println(e.getMessage()); } finally { fastaBuffer.close(); } } }

Read the article

problem with pageFetcher

- by kate

hello i use this code for(int i=0; i < citylink.length; i++){ body=pF.fetchpage(citylink[i][1]); //it's for taking the url from the table citylink and returns the source of this url!! i have also declare it in my pagefetcher.java class like this public String fetchPage(String url) { try { url = URIUtil.encodeQuery(url); } catch (URIException e) { // TODO Auto-generated catch block e.printStackTrace(); } but when i compile it it says that The method fetchpage(String) is undefined for the type PageFetcher and i can't run my problem!!! i don't know what to do

Read the article

Java application return codes

- by doele

I have a Java program that processes one file at a time. This Java program is called from a wrapper script which logs the return code from the Java program. There are 2 types of errors. Expected errors and unexpected errors. In both cases I just need to log them. My wrapper knows about 3 different states. 0-OK, 1-PROCESSING_FAILED, 2- ERROR. Is this a valid approach? Here is my approach: enum ReturnCodes {OK,PROCESSING_FAILED,ERROR}; public static void main(String[] args) { ... proc.processMyFile(); ... System.exit(ReturnCodes.OK.ordinal()); } catch (Throwable t) { ... System.exit(ReturnCodes.ERROR.ordinal()); } private void processMyFile() { try { ... }catch( ExpectedException e) { ... System.exit(ReturnCodes.PROCESSING_FAILED.ordinal()); } }

Read the article

SQLite - executeUpdate exception not caught when database does not exist? (Java)

- by giant91

So I was purposely trying to break my program, and I've succeeded. I deleted the sqlite database the program uses, while the program was running, after I already created the connection. Then I attempted to update the database as seen below. Statement stmt; try { stmt = Foo.con.createStatement(); stmt.executeUpdate("INSERT INTO "+table+" VALUES (\'" + itemToAdd + "\')"); } catch(SQLException e) { System.out.println("Error: " + e.toString()); } The problem is, it didn't catch the exception, and continued to run as if the database was updated successfully. Meanwhile the database didn't even exist at that point since this was after I deleted it. Doesn't it check if the database still exists when updating? Do I have to check the database connection manually, every time I update to ensure that the database wasn't corrupted/deleted? Is this the way it is normally done, or is there a simpler/more robust approach? Thank you.

Read the article

any other way to find char array length?

- by user2785137

public static int getLenth(char[] t) { int i=0; int count=0; try { while(t[i]!='\0') { ++count; i++; } return count; } catch(ArrayIndexOutOfBoundsException aiobe) { return count; } } This method returns length of charArray. But my question is, is there is some other "ways" to find the length of charArray without using this try, catch statements & all ?? Thanks in advance :)

Read the article

Can this loop take out 100% CPU?

- by Nitesh Panchal

Hello, I created a chat application and seems to work just fine except that it takes up 100% cpu. Can this loop take out 100% Cpu? If yes, then what do i do to overcome it? @Override public void run(){ try { _objServerSocket = new ServerSocket(17001, 500); while (true) { try { initializeConnection(); addNewChatClient(); Thread.sleep(1000); } catch (Exception ex) { } } } catch (IOException ex) { System.out.println(ex.getCause() + "\n"+ ex.getMessage() + "\n" + ex.getStackTrace()); } } Thanks in advance :)

Read the article

Creating a dynamic, extensible C# Expando Object

- by Rick Strahl

I love dynamic functionality in a strongly typed language because it offers us the best of both worlds. In C# (or any of the main .NET languages) we now have the dynamic type that provides a host of dynamic features for the static C# language. One place where I've found dynamic to be incredibly useful is in building extensible types or types that expose traditionally non-object data (like dictionaries) in easier to use and more readable syntax. I wrote about a couple of these for accessing old school ADO.NET DataRows and DataReaders more easily for example. These classes are dynamic wrappers that provide easier syntax and auto-type conversions which greatly simplifies code clutter and increases clarity in existing code. ExpandoObject in .NET 4.0 Another great use case for dynamic objects is the ability to create extensible objects - objects that start out with a set of static members and then can add additional properties and even methods dynamically. The .NET 4.0 framework actually includes an ExpandoObject class which provides a very dynamic object that allows you to add properties and methods on the fly and then access them again. For example with ExpandoObject you can do stuff like this:dynamic expand = new ExpandoObject(); expand.Name = "Rick"; expand.HelloWorld = (Func<string, string>) ((string name) => { return "Hello " + name; }); Console.WriteLine(expand.Name); Console.WriteLine(expand.HelloWorld("Dufus")); Internally ExpandoObject uses a Dictionary like structure and interface to store properties and methods and then allows you to add and access properties and methods easily. As cool as ExpandoObject is it has a few shortcomings too: It's a sealed type so you can't use it as a base class It only works off 'properties' in the internal Dictionary - you can't expose existing type data It doesn't serialize to XML or with DataContractSerializer/DataContractJsonSerializer Expando - A truly extensible Object ExpandoObject is nice if you just need a dynamic container for a dictionary like structure. However, if you want to build an extensible object that starts out with a set of strongly typed properties and then allows you to extend it, ExpandoObject does not work because it's a sealed class that can't be inherited. I started thinking about this very scenario for one of my applications I'm building for a customer. In this system we are connecting to various different user stores. Each user store has the same basic requirements for username, password, name etc. But then each store also has a number of extended properties that is available to each application. In the real world scenario the data is loaded from the database in a data reader and the known properties are assigned from the known fields in the database. All unknown fields are then 'added' to the expando object dynamically. In the past I've done this very thing with a separate property - Properties - just like I do for this class. But the property and dictionary syntax is not ideal and tedious to work with. I started thinking about how to represent these extra property structures. One way certainly would be to add a Dictionary, or an ExpandoObject to hold all those extra properties. But wouldn't it be nice if the application could actually extend an existing object that looks something like this as you can with the Expando object:public class User : Westwind.Utilities.Dynamic.Expando { public string Email { get; set; } public string Password { get; set; } public string Name { get; set; } public bool Active { get; set; } public DateTime? ExpiresOn { get; set; } } and then simply start extending the properties of this object dynamically? Using the Expando object I describe later you can now do the following:[TestMethod] public void UserExampleTest() { var user = new User(); // Set strongly typed properties user.Email = "[email protected]"; user.Password = "nonya123"; user.Name = "Rickochet"; user.Active = true; // Now add dynamic properties dynamic duser = user; duser.Entered = DateTime.Now; duser.Accesses = 1; // you can also add dynamic props via indexer user["NickName"] = "AntiSocialX"; duser["WebSite"] = "http://www.west-wind.com/weblog"; // Access strong type through dynamic ref Assert.AreEqual(user.Name,duser.Name); // Access strong type through indexer Assert.AreEqual(user.Password,user["Password"]); // access dyanmically added value through indexer Assert.AreEqual(duser.Entered,user["Entered"]); // access index added value through dynamic Assert.AreEqual(user["NickName"],duser.NickName); // loop through all properties dynamic AND strong type properties (true) foreach (var prop in user.GetProperties(true)) { object val = prop.Value; if (val == null) val = "null"; Console.WriteLine(prop.Key + ": " + val.ToString()); } } As you can see this code somewhat blurs the line between a static and dynamic type. You start with a strongly typed object that has a fixed set of properties. You can then cast the object to dynamic (as I discussed in my last post) and add additional properties to the object. You can also use an indexer to add dynamic properties to the object. To access the strongly typed properties you can use either the strongly typed instance, the indexer or the dynamic cast of the object. Personally I think it's kinda cool to have an easy way to access strongly typed properties by string which can make some data scenarios much easier. To access the 'dynamically added' properties you can use either the indexer on the strongly typed object, or property syntax on the dynamic cast. Using the dynamic type allows all three modes to work on both strongly typed and dynamic properties. Finally you can iterate over all properties, both dynamic and strongly typed if you chose. Lots of flexibility. Note also that by default the Expando object works against the (this) instance meaning it extends the current object. You can also pass in a separate instance to the constructor in which case that object will be used to iterate over to find properties rather than this. Using this approach provides some really interesting functionality when use the dynamic type. To use this we have to add an explicit constructor to the Expando subclass:public class User : Westwind.Utilities.Dynamic.Expando { public string Email { get; set; } public string Password { get; set; } public string Name { get; set; } public bool Active { get; set; } public DateTime? ExpiresOn { get; set; } public User() : base() { } // only required if you want to mix in seperate instance public User(object instance) : base(instance) { } } to allow the instance to be passed. When you do you can now do:[TestMethod] public void ExpandoMixinTest() { // have Expando work on Addresses var user = new User( new Address() ); // cast to dynamicAccessToPropertyTest dynamic duser = user; // Set strongly typed properties duser.Email = "[email protected]"; user.Password = "nonya123"; // Set properties on address object duser.Address = "32 Kaiea"; //duser.Phone = "808-123-2131"; // set dynamic properties duser.NonExistantProperty = "This works too"; // shows default value Address.Phone value Console.WriteLine(duser.Phone); } Using the dynamic cast in this case allows you to access *three* different 'objects': The strong type properties, the dynamically added properties in the dictionary and the properties of the instance passed in! Effectively this gives you a way to simulate multiple inheritance (which is scary - so be very careful with this, but you can do it). How Expando works Behind the scenes Expando is a DynamicObject subclass as I discussed in my last post. By implementing a few of DynamicObject's methods you can basically create a type that can trap 'property missing' and 'method missing' operations. When you access a non-existant property a known method is fired that our code can intercept and provide a value for. Internally Expando uses a custom dictionary implementation to hold the dynamic properties you might add to your expandable object. Let's look at code first. The code for the Expando type is straight forward and given what it provides relatively short. Here it is.using System; using System.Collections.Generic; using System.Linq; using System.Dynamic; using System.Reflection; namespace Westwind.Utilities.Dynamic { /// <summary> /// Class that provides extensible properties and methods. This /// dynamic object stores 'extra' properties in a dictionary or /// checks the actual properties of the instance. /// /// This means you can subclass this expando and retrieve either /// native properties or properties from values in the dictionary. /// /// This type allows you three ways to access its properties: /// /// Directly: any explicitly declared properties are accessible /// Dynamic: dynamic cast allows access to dictionary and native properties/methods /// Dictionary: Any of the extended properties are accessible via IDictionary interface /// </summary> [Serializable] public class Expando : DynamicObject, IDynamicMetaObjectProvider { /// <summary> /// Instance of object passed in /// </summary> object Instance; /// <summary> /// Cached type of the instance /// </summary> Type InstanceType; PropertyInfo[] InstancePropertyInfo { get { if (_InstancePropertyInfo == null && Instance != null) _InstancePropertyInfo = Instance.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly); return _InstancePropertyInfo; } } PropertyInfo[] _InstancePropertyInfo; /// <summary> /// String Dictionary that contains the extra dynamic values /// stored on this object/instance /// </summary> /// <remarks>Using PropertyBag to support XML Serialization of the dictionary</remarks> public PropertyBag Properties = new PropertyBag(); //public Dictionary<string,object> Properties = new Dictionary<string, object>(); /// <summary> /// This constructor just works off the internal dictionary and any /// public properties of this object. /// /// Note you can subclass Expando. /// </summary> public Expando() { Initialize(this); } /// <summary> /// Allows passing in an existing instance variable to 'extend'. /// </summary> /// <remarks> /// You can pass in null here if you don't want to /// check native properties and only check the Dictionary! /// </remarks> /// <param name="instance"></param> public Expando(object instance) { Initialize(instance); } protected virtual void Initialize(object instance) { Instance = instance; if (instance != null) InstanceType = instance.GetType(); } /// <summary> /// Try to retrieve a member by name first from instance properties /// followed by the collection entries. /// </summary> /// <param name="binder"></param> /// <param name="result"></param> /// <returns></returns> public override bool TryGetMember(GetMemberBinder binder, out object result) { result = null; // first check the Properties collection for member if (Properties.Keys.Contains(binder.Name)) { result = Properties[binder.Name]; return true; } // Next check for Public properties via Reflection if (Instance != null) { try { return GetProperty(Instance, binder.Name, out result); } catch { } } // failed to retrieve a property result = null; return false; } /// <summary> /// Property setter implementation tries to retrieve value from instance /// first then into this object /// </summary> /// <param name="binder"></param> /// <param name="value"></param> /// <returns></returns> public override bool TrySetMember(SetMemberBinder binder, object value) { // first check to see if there's a native property to set if (Instance != null) { try { bool result = SetProperty(Instance, binder.Name, value); if (result) return true; } catch { } } // no match - set or add to dictionary Properties[binder.Name] = value; return true; } /// <summary> /// Dynamic invocation method. Currently allows only for Reflection based /// operation (no ability to add methods dynamically). /// </summary> /// <param name="binder"></param> /// <param name="args"></param> /// <param name="result"></param> /// <returns></returns> public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result) { if (Instance != null) { try { // check instance passed in for methods to invoke if (InvokeMethod(Instance, binder.Name, args, out result)) return true; } catch { } } result = null; return false; } /// <summary> /// Reflection Helper method to retrieve a property /// </summary> /// <param name="instance"></param> /// <param name="name"></param> /// <param name="result"></param> /// <returns></returns> protected bool GetProperty(object instance, string name, out object result) { if (instance == null) instance = this; var miArray = InstanceType.GetMember(name, BindingFlags.Public | BindingFlags.GetProperty | BindingFlags.Instance); if (miArray != null && miArray.Length > 0) { var mi = miArray[0]; if (mi.MemberType == MemberTypes.Property) { result = ((PropertyInfo)mi).GetValue(instance,null); return true; } } result = null; return false; } /// <summary> /// Reflection helper method to set a property value /// </summary> /// <param name="instance"></param> /// <param name="name"></param> /// <param name="value"></param> /// <returns></returns> protected bool SetProperty(object instance, string name, object value) { if (instance == null) instance = this; var miArray = InstanceType.GetMember(name, BindingFlags.Public | BindingFlags.SetProperty | BindingFlags.Instance); if (miArray != null && miArray.Length > 0) { var mi = miArray[0]; if (mi.MemberType == MemberTypes.Property) { ((PropertyInfo)mi).SetValue(Instance, value, null); return true; } } return false; } /// <summary> /// Reflection helper method to invoke a method /// </summary> /// <param name="instance"></param> /// <param name="name"></param> /// <param name="args"></param> /// <param name="result"></param> /// <returns></returns> protected bool InvokeMethod(object instance, string name, object[] args, out object result) { if (instance == null) instance = this; // Look at the instanceType var miArray = InstanceType.GetMember(name, BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Instance); if (miArray != null && miArray.Length > 0) { var mi = miArray[0] as MethodInfo; result = mi.Invoke(Instance, args); return true; } result = null; return false; } /// <summary> /// Convenience method that provides a string Indexer /// to the Properties collection AND the strongly typed /// properties of the object by name. /// /// // dynamic /// exp["Address"] = "112 nowhere lane"; /// // strong /// var name = exp["StronglyTypedProperty"] as string; /// </summary> /// <remarks> /// The getter checks the Properties dictionary first /// then looks in PropertyInfo for properties. /// The setter checks the instance properties before /// checking the Properties dictionary. /// </remarks> /// <param name="key"></param> /// /// <returns></returns> public object this[string key] { get { try { // try to get from properties collection first return Properties[key]; } catch (KeyNotFoundException ex) { // try reflection on instanceType object result = null; if (GetProperty(Instance, key, out result)) return result; // nope doesn't exist throw; } } set { if (Properties.ContainsKey(key)) { Properties[key] = value; return; } // check instance for existance of type first var miArray = InstanceType.GetMember(key, BindingFlags.Public | BindingFlags.GetProperty); if (miArray != null && miArray.Length > 0) SetProperty(Instance, key, value); else Properties[key] = value; } } /// <summary> /// Returns and the properties of /// </summary> /// <param name="includeProperties"></param> /// <returns></returns> public IEnumerable<KeyValuePair<string,object>> GetProperties(bool includeInstanceProperties = false) { if (includeInstanceProperties && Instance != null) { foreach (var prop in this.InstancePropertyInfo) yield return new KeyValuePair<string, object>(prop.Name, prop.GetValue(Instance, null)); } foreach (var key in this.Properties.Keys) yield return new KeyValuePair<string, object>(key, this.Properties[key]); } /// <summary> /// Checks whether a property exists in the Property collection /// or as a property on the instance /// </summary> /// <param name="item"></param> /// <returns></returns> public bool Contains(KeyValuePair<string, object> item, bool includeInstanceProperties = false) { bool res = Properties.ContainsKey(item.Key); if (res) return true; if (includeInstanceProperties && Instance != null) { foreach (var prop in this.InstancePropertyInfo) { if (prop.Name == item.Key) return true; } } return false; } } } Although the Expando class supports an indexer, it doesn't actually implement IDictionary or even IEnumerable. It only provides the indexer and Contains() and GetProperties() methods, that work against the Properties dictionary AND the internal instance. The reason for not implementing IDictionary is that a) it doesn't add much value since you can access the Properties dictionary directly and that b) I wanted to keep the interface to class very lean so that it can serve as an entity type if desired. Implementing these IDictionary (or even IEnumerable) causes LINQ extension methods to pop up on the type which obscures the property interface and would only confuse the purpose of the type. IDictionary and IEnumerable are also problematic for XML and JSON Serialization - the XML Serializer doesn't serialize IDictionary<string,object>, nor does the DataContractSerializer. The JavaScriptSerializer does serialize, but it treats the entire object like a dictionary and doesn't serialize the strongly typed properties of the type, only the dictionary values which is also not desirable. Hence the decision to stick with only implementing the indexer to support the user["CustomProperty"] functionality and leaving iteration functions to the publicly exposed Properties dictionary. Note that the Dictionary used here is a custom PropertyBag class I created to allow for serialization to work. One important aspect for my apps is that whatever custom properties get added they have to be accessible to AJAX clients since the particular app I'm working on is a SIngle Page Web app where most of the Web access is through JSON AJAX calls. PropertyBag can serialize to XML and one way serialize to JSON using the JavaScript serializer (not the DCS serializers though). The key components that make Expando work in this code are the Properties Dictionary and the TryGetMember() and TrySetMember() methods. The Properties collection is public so if you choose you can explicitly access the collection to get better performance or to manipulate the members in internal code (like loading up dynamic values form a database). Notice that TryGetMember() and TrySetMember() both work against the dictionary AND the internal instance to retrieve and set properties. This means that user["Name"] works against native properties of the object as does user["Name"] = "RogaDugDog". What's your Use Case? This is still an early prototype but I've plugged it into one of my customer's applications and so far it's working very well. The key features for me were the ability to easily extend the type with values coming from a database and exposing those values in a nice and easy to use manner. I'm also finding that using this type of object for ViewModels works very well to add custom properties to view models. I suspect there will be lots of uses for this - I've been using the extra dictionary approach to extensibility for years - using a dynamic type to make the syntax cleaner is just a bonus here. What can you think of to use this for? Resources Source Code and Tests (GitHub) Also integrated in Westwind.Utilities of the West Wind Web Toolkit West Wind Utilities NuGet© Rick Strahl, West Wind Technologies, 2005-2012Posted in CSharp .NET Dynamic Types Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

Read the article

Parallelism in .NET – Part 10, Cancellation in PLINQ and the Parallel class

- by Reed

Many routines are parallelized because they are long running processes. When writing an algorithm that will run for a long period of time, its typically a good practice to allow that routine to be cancelled. I previously discussed terminating a parallel loop from within, but have not demonstrated how a routine can be cancelled from the caller’s perspective. Cancellation in PLINQ and the Task Parallel Library is handled through a new, unified cooperative cancellation model introduced with .NET 4.0. Cancellation in .NET 4 is based around a new, lightweight struct called CancellationToken. A CancellationToken is a small, thread-safe value type which is generated via a CancellationTokenSource. There are many goals which led to this design. For our purposes, we will focus on a couple of specific design decisions: Cancellation is cooperative. A calling method can request a cancellation, but it’s up to the processing routine to terminate – it is not forced. Cancellation is consistent. A single method call requests a cancellation on every copied CancellationToken in the routine. Let’s begin by looking at how we can cancel a PLINQ query. Supposed we wanted to provide the option to cancel our query from Part 6: double min = collection .AsParallel() .Min(item => item.PerformComputation()); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } We would rewrite this to allow for cancellation by adding a call to ParallelEnumerable.WithCancellation as follows: var cts = new CancellationTokenSource(); // Pass cts here to a routine that could, // in parallel, request a cancellation try { double min = collection .AsParallel() .WithCancellation(cts.Token) .Min(item => item.PerformComputation()); } catch (OperationCanceledException e) { // Query was cancelled before it finished } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, if the user calls cts.Cancel() before the PLINQ query completes, the query will stop processing, and an OperationCanceledException will be raised. Be aware, however, that cancellation will not be instantaneous. When cts.Cancel() is called, the query will only stop after the current item.PerformComputation() elements all finish processing. cts.Cancel() will prevent PLINQ from scheduling a new task for a new element, but will not stop items which are currently being processed. This goes back to the first goal I mentioned – Cancellation is cooperative. Here, we’re requesting the cancellation, but it’s up to PLINQ to terminate. If we wanted to allow cancellation to occur within our routine, we would need to change our routine to accept a CancellationToken, and modify it to handle this specific case: public void PerformComputation(CancellationToken token) { for (int i=0; i<this.iterations; ++i) { // Add a check to see if we've been canceled // If a cancel was requested, we'll throw here token.ThrowIfCancellationRequested(); // Do our processing now this.RunIteration(i); } } With this overload of PerformComputation, each internal iteration checks to see if a cancellation request was made, and will throw an OperationCanceledException at that point, instead of waiting until the method returns. This is good, since it allows us, as developers, to plan for cancellation, and terminate our routine in a clean, safe state. This is handled by changing our PLINQ query to: try { double min = collection .AsParallel() .WithCancellation(cts.Token) .Min(item => item.PerformComputation(cts.Token)); } catch (OperationCanceledException e) { // Query was cancelled before it finished } PLINQ is very good about handling this exception, as well. There is a very good chance that multiple items will raise this exception, since the entire purpose of PLINQ is to have multiple items be processed concurrently. PLINQ will take all of the OperationCanceledException instances raised within these methods, and merge them into a single OperationCanceledException in the call stack. This is done internally because we added the call to ParallelEnumerable.WithCancellation. If, however, a different exception is raised by any of the elements, the OperationCanceledException as well as the other Exception will be merged into a single AggregateException. The Task Parallel Library uses the same cancellation model, as well. Here, we supply our CancellationToken as part of the configuration. The ParallelOptions class contains a property for the CancellationToken. This allows us to cancel a Parallel.For or Parallel.ForEach routine in a very similar manner to our PLINQ query. As an example, we could rewrite our Parallel.ForEach loop from Part 2 to support cancellation by changing it to: try { var cts = new CancellationTokenSource(); var options = new ParallelOptions() { CancellationToken = cts.Token }; Parallel.ForEach(customers, options, customer => { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // Check for cancellation here options.CancellationToken.ThrowIfCancellationRequested(); // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { theStore.EmailCustomer(customer); customer.LastEmailContact = DateTime.Now; } }); } catch (OperationCanceledException e) { // The loop was cancelled } Notice that here we use the same approach taken in PLINQ. The Task Parallel Library will automatically handle our cancellation in the same manner as PLINQ, providing a clean, unified model for cancellation of any parallel routine. The TPL performs the same aggregation of the cancellation exceptions as PLINQ, as well, which is why a single exception handler for OperationCanceledException will cleanly handle this scenario. This works because we’re using the same CancellationToken provided in the ParallelOptions. If a different exception was thrown by one thread, or a CancellationToken from a different CancellationTokenSource was used to raise our exception, we would instead receive all of our individual exceptions merged into one AggregateException.

Read the article

WatiN screenshot saver

- by Brian Schroer

In addition to my automated unit, system and integration tests for ASP.NET projects, I like to give my customers something pretty that they can look at and visually see that the web site is behaving properly. I use the Gallio test runner to produce a pretty HTML report, and WatiN (Web Application Testing In .NET) to test the UI and create screenshots. I have a couple of issues with WatiN’s “CaptureWebPageToFile” method, though: It blew up the first (and only) time I tried it, possibly because… It scrolls down to capture the entire web page (I tried it on a very long page), and I usually don’t need that Also, sometimes I don’t need a picture of the whole browser window - I just want a picture of the element that I'm testing (for example, proving that a button has the correct caption). I wrote a WatiN screenshot saver helper class with these methods: SaveBrowserWindowScreenshot(Watin.Core.IE ie) / SaveBrowserWindowScreenshot(Watin.Core.Element element) saves a screenshot of the browser window SaveBrowserWindowScreenshotWithHighlight(Watin.Core.Element element) saves a screenshot of the browser window, with the specified element scrolled into view and highlighted SaveElementScreenshot(Watin.Core.Element element) saves a picture of only the specified element The element highlighting improves on the built-in WatiN method (which just gives the element a yellow background, and makes the element pretty much unreadable when you have a light foreground color) by adding the ability to specify a HighlightCssClassName that points to a style in your site’s stylesheet. This code is specifically for testing with Internet Explorer (‘cause that’s what I have to test with at work), but you’re welcome to take it and do with it what you want… using System; using System.Drawing; using System.Drawing.Imaging; using System.IO; using System.Reflection; using System.Runtime.InteropServices; using System.Text; using System.Threading; using SHDocVw; using WatiN.Core; using mshtml; namespace BrianSchroer.TestHelpers { public static class WatinScreenshotSaver { public static void SaveBrowserWindowScreenshotWithHighlight (Element element, string screenshotName) { HighlightElement(element, true); SaveBrowserWindowScreenshot(element, screenshotName); HighlightElement(element, false); } public static void SaveBrowserWindowScreenshotWithHighlight(Element element) { HighlightElement(element, true); SaveBrowserWindowScreenshot(element); HighlightElement(element, false); } public static void SaveBrowserWindowScreenshot(Element element, string screenshotName) { SaveScreenshot(GetIe(element), screenshotName, SaveBitmapForCallbackArgs); } public static void SaveBrowserWindowScreenshot(Element element) { SaveScreenshot(GetIe(element), null, SaveBitmapForCallbackArgs); } public static void SaveBrowserWindowScreenshot(IE ie, string screenshotName) { SaveScreenshot(ie, screenshotName, SaveBitmapForCallbackArgs); } public static void SaveBrowserWindowScreenshot(IE ie) { SaveScreenshot(ie, null, SaveBitmapForCallbackArgs); } public static void SaveElementScreenshot(Element element, string screenshotName) { // TODO: Figure out how to get browser window "chrome" size and not have to go to full screen: var iex = (InternetExplorerClass) GetIe(element).InternetExplorer; bool fullScreen = iex.FullScreen; if (!fullScreen) iex.FullScreen = true; ScrollIntoView(element); SaveScreenshot(GetIe(element), screenshotName, args => SaveElementBitmapForCallbackArgs(element, args)); iex.FullScreen = fullScreen; } public static void SaveElementScreenshot(Element element) { SaveElementScreenshot(element, null); } private static void SaveScreenshot(IE browser, string screenshotName, Action<ScreenshotCallbackArgs> screenshotCallback) { string fileName = string.Format("{0:000}{1}{2}.jpg", ++_screenshotCount, (string.IsNullOrEmpty(screenshotName)) ? "" : " ", screenshotName); string path = Path.Combine(ScreenshotDirectoryName, fileName); Console.WriteLine(); // Gallio HTML-encodes the following display, but I have a utility program to // remove the "HTML===" and "===HTML" and un-encode the rest to show images in the Gallio report: Console.WriteLine("HTML===<div><b>{0}:</br></b><img src=\"{1}\" /></div>===HTML", screenshotName, new Uri(path).AbsoluteUri); MakeBrowserWindowTopmost(browser); try { var args = new ScreenshotCallbackArgs { InternetExplorerClass = (InternetExplorerClass)browser.InternetExplorer, ScreenshotPath = path }; Thread.Sleep(100); screenshotCallback(args); } catch (Exception ex) { Console.WriteLine(ex.Message); } } public static void HighlightElement(Element element, bool doHighlight) { if (!element.Exists) return; if (string.IsNullOrEmpty(HighlightCssClassName)) { element.Highlight(doHighlight); return; } string jsRef = element.GetJavascriptElementReference(); if (string.IsNullOrEmpty(jsRef)) return; var sb = new StringBuilder("try { "); sb.AppendFormat(" {0}.scrollIntoView(false);", jsRef); string format = (doHighlight) ? "{0}.className += ' {1}'" : "{0}.className = {0}.className.replace(' {1}', '')"; sb.AppendFormat(" " + format + ";", jsRef, HighlightCssClassName); sb.Append("} catch(e) {}"); string script = sb.ToString(); GetIe(element).RunScript(script); } public static void ScrollIntoView(Element element) { string jsRef = element.GetJavascriptElementReference(); if (string.IsNullOrEmpty(jsRef)) return; var sb = new StringBuilder("try { "); sb.AppendFormat(" {0}.scrollIntoView(false);", jsRef); sb.Append("} catch(e) {}"); string script = sb.ToString(); GetIe(element).RunScript(script); } public static void MakeBrowserWindowTopmost(IE ie) { ie.BringToFront(); SetWindowPos(ie.hWnd, HWND_TOPMOST, 0, 0, 0, 0, TOPMOST_FLAGS); } public static string HighlightCssClassName { get; set; } private static int _screenshotCount; private static string _screenshotDirectoryName; public static string ScreenshotDirectoryName { get { if (_screenshotDirectoryName == null) { var asm = Assembly.GetAssembly(typeof(WatinScreenshotSaver)); var uri = new Uri(asm.CodeBase); var fileInfo = new FileInfo(uri.LocalPath); string directoryName = fileInfo.DirectoryName; _screenshotDirectoryName = Path.Combine( directoryName, string.Format("Screenshots_{0:yyyyMMddHHmm}", DateTime.Now)); Console.WriteLine("Screenshot folder: {0}", _screenshotDirectoryName); Directory.CreateDirectory(_screenshotDirectoryName); } return _screenshotDirectoryName; } set { _screenshotDirectoryName = value; _screenshotCount = 0; } } [DllImport("user32.dll")] [return: MarshalAs(UnmanagedType.Bool)] private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags); private static readonly IntPtr HWND_TOPMOST = new IntPtr(-1); private const UInt32 SWP_NOSIZE = 0x0001; private const UInt32 SWP_NOMOVE = 0x0002; private const UInt32 TOPMOST_FLAGS = SWP_NOMOVE | SWP_NOSIZE; private static IE GetIe(Element element) { if (element == null) return null; var container = element.DomContainer; while (container as IE == null) container = container.DomContainer; return (IE)container; } private static void SaveBitmapForCallbackArgs(ScreenshotCallbackArgs args) { InternetExplorerClass iex = args.InternetExplorerClass; SaveBitmap(args.ScreenshotPath, iex.Left, iex.Top, iex.Width, iex.Height); } private static void SaveElementBitmapForCallbackArgs(Element element, ScreenshotCallbackArgs args) { InternetExplorerClass iex = args.InternetExplorerClass; Rectangle bounds = GetElementBounds(element); SaveBitmap(args.ScreenshotPath, iex.Left + bounds.Left, iex.Top + bounds.Top, bounds.Width, bounds.Height); } /// <summary> /// This method is used instead of element.NativeElement.GetElementBounds because that /// method has a bug (http://sourceforge.net/tracker/?func=detail&aid=2994660&group_id=167632&atid=843727). /// </summary> private static Rectangle GetElementBounds(Element element) { var ieElem = element.NativeElement as WatiN.Core.Native.InternetExplorer.IEElement; IHTMLElement elem = ieElem.AsHtmlElement; int left = elem.offsetLeft; int top = elem.offsetTop; for (IHTMLElement parent = elem.offsetParent; parent != null; parent = parent.offsetParent) { left += parent.offsetLeft; top += parent.offsetTop; } return new Rectangle(left, top, elem.offsetWidth, elem.offsetHeight); } private static void SaveBitmap(string path, int left, int top, int width, int height) { using (var bitmap = new Bitmap(width, height)) { using (Graphics g = Graphics.FromImage(bitmap)) { g.CopyFromScreen( new Point(left, top), Point.Empty, new Size(width, height) ); } bitmap.Save(path, ImageFormat.Jpeg); } } private class ScreenshotCallbackArgs { public InternetExplorerClass InternetExplorerClass { get; set; } public string ScreenshotPath { get; set; } } } }

Read the article

Enterprise Library Logging / Exception handling and Postsharp

- by subodhnpushpak

One of my colleagues came-up with a unique situation where it was required to create log files based on the input file which is uploaded. For example if A.xml is uploaded, the corresponding log file should be A_log.txt. I am a strong believer that Logging / EH / caching are cross-cutting architecture aspects and should be least invasive to the business-logic written in enterprise application. I have been using Enterprise Library for logging / EH (i use to work with Avanade, so i have affection towards the library!! :D ). I have been also using excellent library called PostSharp for cross cutting aspect. Here i present a solution with and without PostSharp all in a unit test. Please see full source code at end of the this blog post. But first, we need to tweak the enterprise library so that the log files are created at runtime based on input given. Below is Custom trace listner which writes log into a given file extracted out of Logentry extendedProperties property. using Microsoft.Practices.EnterpriseLibrary.Common.Configuration; using Microsoft.Practices.EnterpriseLibrary.Logging.Configuration; using Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners; using Microsoft.Practices.EnterpriseLibrary.Logging; using System.IO; using System.Text; using System; using System.Diagnostics; namespace Subodh.Framework.Logging { [ConfigurationElementType(typeof(CustomTraceListenerData))] public class LogToFileTraceListener : CustomTraceListener { private static object syncRoot = new object(); public override void TraceData(TraceEventCache eventCache, string source, TraceEventType eventType, int id, object data) { if ((data is LogEntry) & this.Formatter != null) { WriteOutToLog(this.Formatter.Format((LogEntry)data), (LogEntry)data); } else { WriteOutToLog(data.ToString(), (LogEntry)data); } } public override void Write(string message) { Debug.Print(message.ToString()); } public override void WriteLine(string message) { Debug.Print(message.ToString()); } private void WriteOutToLog(string BodyText, LogEntry logentry) { try { //Get the filelocation from the extended properties if (logentry.ExtendedProperties.ContainsKey("filelocation")) { string fullPath = Path.GetFullPath(logentry.ExtendedProperties["filelocation"].ToString()); //Create the directory where the log file is written to if it does not exist. DirectoryInfo directoryInfo = new DirectoryInfo(Path.GetDirectoryName(fullPath)); if (directoryInfo.Exists == false) { directoryInfo.Create(); } //Lock the file to prevent another process from using this file //as data is being written to it. lock (syncRoot) { using (FileStream fs = new FileStream(fullPath, FileMode.Append, FileAccess.Write, FileShare.Write, 4096, true)) { using (StreamWriter sw = new StreamWriter(fs, Encoding.UTF8)) { Log(BodyText, sw); sw.Close(); } fs.Close(); } } } } catch (Exception ex) { throw new LoggingException(ex.Message, ex); } } /// <summary> /// Write message to named file /// </summary> public static void Log(string logMessage, TextWriter w) { w.WriteLine("{0}", logMessage); } } } The above can be “plugged into” the code using below configuration <loggingConfiguration name="Logging Application Block" tracingEnabled="true" defaultCategory="Trace" logWarningsWhenNoCategoriesMatch="true"> <listeners> <add listenerDataType="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.CustomTraceListenerData, Microsoft.Practices.EnterpriseLibrary.Logging, Version=4.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" traceOutputOptions="None" filter="All" type="Subodh.Framework.Logging.LogToFileTraceListener, Subodh.Framework.Logging, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Subodh Custom Trace Listener" initializeData="" formatter="Text Formatter" /> </listeners> Similarly we can use PostSharp to expose the above as cross cutting aspects as below using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Reflection; using PostSharp.Laos; using System.Diagnostics; using GC.FrameworkServices.ExceptionHandler; using Subodh.Framework.Logging; namespace Subodh.Framework.ExceptionHandling { [Serializable] public sealed class LogExceptionAttribute : OnExceptionAspect { private string prefix; private MethodFormatStrings formatStrings; // This field is not serialized. It is used only at compile time. [NonSerialized] private readonly Type exceptionType; private string fileName; /// <summary> /// Declares a <see cref="XTraceExceptionAttribute"/> custom attribute /// that logs every exception flowing out of the methods to which /// the custom attribute is applied. /// </summary> public LogExceptionAttribute() { } /// <summary> /// Declares a <see cref="XTraceExceptionAttribute"/> custom attribute /// that logs every exception derived from a given <see cref="Type"/> /// flowing out of the methods to which /// the custom attribute is applied. /// </summary> /// <param name="exceptionType"></param> public LogExceptionAttribute( Type exceptionType ) { this.exceptionType = exceptionType; } public LogExceptionAttribute(Type exceptionType, string fileName) { this.exceptionType = exceptionType; this.fileName = fileName; } /// <summary> /// Gets or sets the prefix string, printed before every trace message. /// </summary> /// <value> /// For instance <c>[Exception]</c>. /// </value> public string Prefix { get { return this.prefix; } set { this.prefix = value; } } /// <summary> /// Initializes the current object. Called at compile time by PostSharp. /// </summary> /// <param name="method">Method to which the current instance is /// associated.</param> public override void CompileTimeInitialize( MethodBase method ) { // We just initialize our fields. They will be serialized at compile-time // and deserialized at runtime. this.formatStrings = Formatter.GetMethodFormatStrings( method ); this.prefix = Formatter.NormalizePrefix( this.prefix ); } public override Type GetExceptionType( MethodBase method ) { return this.exceptionType; } /// <summary> /// Method executed when an exception occurs in the methods to which the current /// custom attribute has been applied. We just write a record to the tracing /// subsystem. /// </summary> /// <param name="context">Event arguments specifying which method /// is being called and with which parameters.</param> public override void OnException( MethodExecutionEventArgs context ) { string message = String.Format("{0}Exception {1} {{{2}}} in {{{3}}}. \r\n\r\nStack Trace {4}", this.prefix, context.Exception.GetType().Name, context.Exception.Message, this.formatStrings.Format(context.Instance, context.Method, context.GetReadOnlyArgumentArray()), context.Exception.StackTrace); if(!string.IsNullOrEmpty(fileName)) { ApplicationLogger.LogException(message, fileName); } else { ApplicationLogger.LogException(message, Source.UtilityService); } } } } To use the above below is the unit test [TestMethod] [ExpectedException(typeof(NotImplementedException))] public void TestMethod1() { MethodThrowingExceptionForLog(); try { MethodThrowingExceptionForLogWithPostSharp(); } catch (NotImplementedException ex) { throw ex; } } private void MethodThrowingExceptionForLog() { try { throw new NotImplementedException(); } catch (NotImplementedException ex) { // create file and then write log ApplicationLogger.TraceMessage("this is a trace message which will be logged in Test1MyFile", @"D:\EL\Test1Myfile.txt"); ApplicationLogger.TraceMessage("this is a trace message which will be logged in YetAnotherTest1Myfile", @"D:\EL\YetAnotherTest1Myfile.txt"); } } // Automatically log details using attributes // Log exception using attributes .... A La WCF [FaultContract(typeof(FaultMessage))] style] [Log(@"D:\EL\Test1MyfileLogPostsharp.txt")] [LogException(typeof(NotImplementedException), @"D:\EL\Test1MyfileExceptionPostsharp.txt")] private void MethodThrowingExceptionForLogWithPostSharp() { throw new NotImplementedException(); } The good thing about the approach is that all the logging and EH is done at centralized location controlled by PostSharp. Of Course, if some other library has to be used instead of EL, it can easily be plugged in. Also, the coder ARE ONLY involved in writing business code in methods, which makes code cleaner. Here is the full source code. The third party assemblies provided are from EL and PostSharp and i presume you will find these useful. Do let me know your thoughts / ideas on the same. Technorati Tags: PostSharp,Enterprize library,C#,Logging,Exception handling

Read the article

How To Watch Live Streaming of Oscars 2011 (Academy Awards)

- by Kavitha

The Academy Awards or more popularly known as Oscars for this year will go live on Sunday, February 27, 2011 (8PM ET/5pm PT) at the Kodak Theatre (Hollywood), Los Angeles, California. It’s a star studded event every movie lover wish to follow and watch live. We at Tech Dreams always love to write about live streaming of popular events happening across the globe. Here is our guide to follow Oscars 2011. Oscars 2011 Live Streams Last year we did not have many choices to view the Oscars online. But this year there are plenty of them available from the best of the media power houses APLive Oscars coverage on livestream.com (embedded below) Oscars.com – The Official Web Site of Academy Awards Oscars.org Live Streaming Academy Awards – Official Live Steaming Channel on livestream.com(embedded below) APLive Oscars coverage on Facebook Watch Oscars 2011 On Your iPad / iPhone You can catch Oscars 2011 on your iOS devices – iPhone, iPad and iPods for the time ever using the official oscar’s application. Application cost $0.99 and you can download it from AppStore Websites To View Highlights & Exclusive Clips Of Oscars 2010 If you miss to catch the live streaming of Oscars 2011, here are few sites you can check to view video highlights of the entire event. Few websites like Hulu have access to exclusive moments. Oscar’s Official YouTube Channel Hulu Award Season 2011 coverage Oscar’s 2011 Event Schedule Oscars 2011 will begin at on 27th February Sunday 8PM EST in California. The local time in India will be around 9:30 AM on Monday. Here is list of major cities and the local time at which Oscars 2011 are going to start Date & Time California February 27th, Sunday 20:00 Adelaide February 28th, Monday 14:30 Bangkok February 28th, Monday 11:00 Beijing February 28th, Monday 12:00 Brisbane February 28th, Monday 14:00 Cape Town February 28th, Monday 06:00 Dubai February 28th, Monday 08:00 Frankfurt February 28th, Monday 05:00 Hong Kong February 28th, Monday 12:00 Delhi/Chennai/Mumbai/Kolkata February 28th, Monday 09:30 New York February 27th, Sunday 23:00 Paris February 28th, Monday 05:00 Washington February 27th, Sunday 23:00 London February 28th, Monday 04:00 or more cities visit this link This article titled,How To Watch Live Streaming of Oscars 2011 (Academy Awards), was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

Read the article

Microsoft SQL Server High-Availability Videos and Q&A Log

- by KKline

You Want Videos? We Got Videos! I always enjoy getting the chance to catch up with author, consultant, and Microsoft Clustering MVP Allan Hirt . Allan and I recently presented two sessions covering an overview of high availability in Microsoft SQL Server and, the following week, a demo of how to implement several different kinds of high availability techniques including database mirroring, transactional replication, and Windows clustering services. You can see videos of these presentations at the...(read more)

Read the article

WLS MBeans

- by Jani Rautiainen

WLS provides a set of Managed Beans (MBeans) to configure, monitor and manage WLS resources. We can use the WLS MBeans to automate some of the tasks related to the configuration and maintenance of the WLS instance. The MBeans can be accessed a number of ways; using various UIs and programmatically using Java or WLST Python scripts.For customization development we can use the features to e.g. manage the deployed customization in MDS, control logging levels, automate deployment of dependent libraries etc. This article is an introduction on how to access and use the WLS MBeans. The goal is to illustrate the various access methods in a single article; the details of the features are left to the linked documentation.This article covers Windows based environment, steps for Linux would be similar however there would be some differences e.g. on how the file paths are defined. MBeansThe WLS MBeans can be categorized to runtime and configuration MBeans.The Runtime MBeans can be used to access the runtime information about the server and its resources. The data from runtime beans is only available while the server is running. The runtime beans can be used to e.g. check the state of the server or deployment.The Configuration MBeans contain information about the configuration of servers and resources. The configuration of the domain is stored in the config.xml file and the configuration MBeans can be used to access and modify the configuration data. For more information on the WLS MBeans refer to: Understanding WebLogic Server MBeans WLS MBean reference Java Management Extensions (JMX)We can use JMX APIs to access the WLS MBeans. This allows us to create Java programs to configure, monitor, and manage WLS resources. In order to use the WLS MBeans we need to add the following library into the class-path: WL_HOME\lib\wljmxclient.jar Connecting to a WLS MBean server The WLS MBeans are contained in a Mbean server, depending on the requirement we can connect to (MBean Server / JNDI Name): Domain Runtime MBean Server weblogic.management.mbeanservers.domainruntime Runtime MBean Server weblogic.management.mbeanservers.runtime Edit MBean Server weblogic.management.mbeanservers.edit To connect to the WLS MBean server first we need to create a map containing the credentials; Hashtable<String, String> param = new Hashtable<String, String>(); param.put(Context.SECURITY_PRINCIPAL, "weblogic"); param.put(Context.SECURITY_CREDENTIALS, "weblogic1"); param.put(JMXConnectorFactory.PROTOCOL_PROVIDER_PACKAGES, "weblogic.management.remote"); These define the user, password and package containing the protocol. Next we create the connection: JMXServiceURL serviceURL = new JMXServiceURL("t3","127.0.0.1",7101, "/jndi/weblogic.management.mbeanservers.domainruntime"); JMXConnector connector = JMXConnectorFactory.connect(serviceURL, param); MBeanServerConnection connection = connector.getMBeanServerConnection(); With the connection we can now access the MBeans for the WLS instance. For a complete example see Appendix A of this post. For more details refer to Accessing WebLogic Server MBeans with JMX Accessing WLS MBeans The WLS MBeans are structured hierarchically; in order to access content we need to know the path to the MBean we are interested in. The MBean is accessed using “MBeanServerConnection. getAttribute” API. WLS provides entry points to the hierarchy allowing us to navigate all the WLS MBeans in the hierarchy (MBean Server / JMX object name): Domain Runtime MBean Server com.bea:Name=DomainRuntimeService,Type=weblogic.management.mbeanservers.domainruntime.DomainRuntimeServiceMBean Runtime MBean Servers com.bea:Name=RuntimeService,Type=weblogic.management.mbeanservers.runtime.RuntimeServiceMBean Edit MBean Server com.bea:Name=EditService,Type=weblogic.management.mbeanservers.edit.EditServiceMBean For example we can access the Domain Runtime MBean using: ObjectName service = new ObjectName( "com.bea:Name=DomainRuntimeService," + "Type=weblogic.management.mbeanservers.domainruntime.DomainRuntimeServiceMBean"); Same syntax works for any “child” WLS MBeans e.g. to find out all application deployments we can: ObjectName domainConfig = (ObjectName)connection.getAttribute(service,"DomainConfiguration"); ObjectName[] appDeployments = (ObjectName[])connection.getAttribute(domainConfig,"AppDeployments"); Alternatively we could access the same MBean using the full syntax: ObjectName domainConfig = new ObjectName("com.bea:Location=DefaultDomain,Name=DefaultDomain,Type=Domain"); ObjectName[] appDeployments = (ObjectName[])connection.getAttribute(domainConfig,"AppDeployments"); For more details refer to Accessing WebLogic Server MBeans with JMX Invoking operations on WLS MBeans The WLS MBean operations can be invoked with MBeanServerConnection. invoke API; in the following example we query the state of “AppsLoggerService” application: ObjectName appRuntimeStateRuntime = new ObjectName("com.bea:Name=AppRuntimeStateRuntime,Type=AppRuntimeStateRuntime"); Object[] parameters = { "AppsLoggerService", "DefaultServer" }; String[] signature = { "java.lang.String", "java.lang.String" }; String result = (String)connection.invoke(appRuntimeStateRuntime,"getCurrentState",parameters, signature); The result returned should be "STATE_ACTIVE" assuming the "AppsLoggerService" application is up and running. WebLogic Scripting Tool (WLST) The WebLogic Scripting Tool (WLST) is a command-line scripting environment that we can access the same WLS MBeans. The tool is located under: $MW_HOME\oracle_common\common\bin\wlst.bat Do note that there are several instances of the wlst script under the $MW_HOME, each of them works, however the commands available vary, so we want to use the one under “oracle_common”. The tool is started in offline mode. In offline mode we can access and manipulate the domain configuration. In online mode we can access the runtime information. We connect to the Administration Server : connect("weblogic","weblogic1", "t3://127.0.0.1:7101") In both online and offline modes we can navigate the WLS MBean using commands like "ls" to print content and "cd" to navigate between objects, for example: All the commands available can be obtained with: help('all') For details of the tool refer to WebLogic Scripting Tool and for the commands available WLST Command and Variable Reference. Also do note that the WLST tool can be invoked from Java code in Embedded Mode. Running Scripts The WLST tool allows us to automate tasks using Python scripts in Script Mode. The script can be manually created or recorded by the WLST tool. Example commands of recording a script: startRecording("c:/temp/recording.py") <commands that we want to record> stopRecording() We can run the script from WLST: execfile("c:/temp/recording.py") We can also run the script from the command line: C:\apps\Oracle\Middleware\oracle_common\common\bin\wlst.cmd c:/temp/recording.py There are various sample scripts are provided with the WLS instance. UI to Access the WLS MBeans There are various UIs through which we can access the WLS MBeans. Oracle Enterprise Manager Fusion Middleware Control Oracle WebLogic Server Administration Console Fusion Middleware Control MBean Browser In the integrated JDeveloper environment only the Oracle WebLogic Server Administration Console is available to us. For more information refer to the documentation, one noteworthy feature in the console is the ability to record WLST scripts based on the navigation. In addition to the UIs above the JConsole included in the JDK can be used to access the WLS MBeans. The JConsole needs to be started with specific parameter to force WLS objects to be used and jar files in the classpath: "C:\apps\Oracle\Middleware\jdk160_24\bin\jconsole" -J-Djava.class.path=C:\apps\Oracle\Middleware\jdk160_24\lib\jconsole.jar;C:\apps\Oracle\Middleware\jdk160_24\lib\tools.jar;C:\apps\Oracle\Middleware\wlserver_10.3\server\lib\wljmxclient.jar -J-Djmx.remote.protocol.provider.pkgs=weblogic.management.remote For more details refer to the Accessing Custom MBeans from JConsole. Summary In this article we have covered various ways we can access and use the WLS MBeans in context of integrated WLS in JDeveloper to be used for Fusion Application customization development. References Developing Custom Management Utilities With JMX for Oracle WebLogic Server Accessing WebLogic Server MBeans with JMX WebLogic Server MBean Reference WebLogic Scripting Tool WLST Command and Variable Reference Appendix A package oracle.apps.test; import java.io.IOException;import java.net.MalformedURLException;import java.util.Hashtable;import javax.management.MBeanServerConnection;import javax.management.MalformedObjectNameException;import javax.management.ObjectName;import javax.management.remote.JMXConnector;import javax.management.remote.JMXConnectorFactory;import javax.management.remote.JMXServiceURL;import javax.naming.Context;/** * This class contains simple examples on how to access WLS MBeans using JMX. */public class BlogExample { /** * Connection to the WLS MBeans */ private MBeanServerConnection connection; /** * Constructor that takes in the connection information for the * domain and obtains the resources from WLS MBeans using JMX. * @param hostName host name to connect to for the WLS server * @param port port to connect to for the WLS server * @param userName user name to connect to for the WLS server * @param password password to connect to for the WLS server */ public BlogExample(String hostName, String port, String userName, String password) { super(); try { initConnection(hostName, port, userName, password); } catch (Exception e) { throw new RuntimeException("Unable to connect to the domain " + hostName + ":" + port); } } /** * Default constructor. * Tries to create connection with default values. Runtime exception will be * thrown if the default values are not used in the local instance. */ public BlogExample() { this("127.0.0.1", "7101", "weblogic", "weblogic1"); } /** * Initializes the JMX connection to the WLS Beans * @param hostName host name to connect to for the WLS server * @param port port to connect to for the WLS server * @param userName user name to connect to for the WLS server * @param password password to connect to for the WLS server * @throws IOException error connecting to the WLS MBeans * @throws MalformedURLException error connecting to the WLS MBeans * @throws MalformedObjectNameException error connecting to the WLS MBeans */ private void initConnection(String hostName, String port, String userName, String password) throws IOException, MalformedURLException, MalformedObjectNameException { String protocol = "t3"; String jndiroot = "/jndi/"; String mserver = "weblogic.management.mbeanservers.domainruntime"; JMXServiceURL serviceURL = new JMXServiceURL(protocol, hostName, Integer.valueOf(port), jndiroot + mserver); Hashtable<String, String> h = new Hashtable<String, String>(); h.put(Context.SECURITY_PRINCIPAL, userName); h.put(Context.SECURITY_CREDENTIALS, password); h.put(JMXConnectorFactory.PROTOCOL_PROVIDER_PACKAGES, "weblogic.management.remote"); JMXConnector connector = JMXConnectorFactory.connect(serviceURL, h); connection = connector.getMBeanServerConnection(); } /** * Main method used to invoke the logic for testing * @param args arguments passed to the program */ public static void main(String[] args) { BlogExample blogExample = new BlogExample(); blogExample.testEntryPoint(); blogExample.testDirectAccess(); blogExample.testInvokeOperation(); } /** * Example of using an entry point to navigate the WLS MBean hierarchy. */ public void testEntryPoint() { try { System.out.println("testEntryPoint"); ObjectName service = new ObjectName("com.bea:Name=DomainRuntimeService,Type=" +"weblogic.management.mbeanservers.domainruntime.DomainRuntimeServiceMBean"); ObjectName domainConfig = (ObjectName)connection.getAttribute(service, "DomainConfiguration"); ObjectName[] appDeployments = (ObjectName[])connection.getAttribute(domainConfig, "AppDeployments"); for (ObjectName appDeployment : appDeployments) { String resourceIdentifier = (String)connection.getAttribute(appDeployment, "SourcePath"); System.out.println(resourceIdentifier); } } catch (Exception e) { throw new RuntimeException(e); } } /** * Example of accessing WLS MBean directly with a full reference. * This does the same thing as testEntryPoint in slightly difference way. */ public void testDirectAccess() { try { System.out.println("testDirectAccess"); ObjectName appDeployment = new ObjectName("com.bea:Location=DefaultDomain,"+ "Name=AppsLoggerService,Type=AppDeployment"); String resourceIdentifier = (String)connection.getAttribute(appDeployment, "SourcePath"); System.out.println(resourceIdentifier); } catch (Exception e) { throw new RuntimeException(e); } } /** * Example of invoking operation on a WLS MBean. */ public void testInvokeOperation() { try { System.out.println("testInvokeOperation"); ObjectName appRuntimeStateRuntime = new ObjectName("com.bea:Name=AppRuntimeStateRuntime,"+ "Type=AppRuntimeStateRuntime"); String identifier = "AppsLoggerService"; String serverName = "DefaultServer"; Object[] parameters = { identifier, serverName }; String[] signature = { "java.lang.String", "java.lang.String" }; String result = (String)connection.invoke(appRuntimeStateRuntime, "getCurrentState", parameters, signature); System.out.println("State of " + identifier + " = " + result); } catch (Exception e) { throw new RuntimeException(e); } }}

Read the article

Syncing Data with a Server using Silverlight and HTTP Polling Duplex

- by dwahlin

Many applications have the need to stay in-sync with data provided by a service. Although web applications typically rely on standard polling techniques to check if data has changed, Silverlight provides several interesting options for keeping an application in-sync that rely on server “push” technologies. A few years back I wrote several blog posts covering different “push” technologies available in Silverlight that rely on sockets or HTTP Polling Duplex. We recently had a project that looked like it could benefit from pushing data from a server to one or more clients so I thought I’d revisit the subject and provide some updates to the original code posted. If you’ve worked with AJAX before in Web applications then you know that until browsers fully support web sockets or other duplex (bi-directional communication) technologies that it’s difficult to keep applications in-sync with a server without relying on polling. The problem with polling is that you have to check for changes on the server on a timed-basis which can often be wasteful and take up unnecessary resources. With server “push” technologies, data can be pushed from the server to the client as it changes. Once the data is received, the client can update the user interface as appropriate. Using “push” technologies allows the client to listen for changes from the data but stay 100% focused on client activities as opposed to worrying about polling and asking the server if anything has changed. Silverlight provides several options for pushing data from a server to a client including sockets, TCP bindings and HTTP Polling Duplex. Each has its own strengths and weaknesses as far as performance and setup work with HTTP Polling Duplex arguably being the easiest to setup and get going. In this article I’ll demonstrate how HTTP Polling Duplex can be used in Silverlight 4 applications to push data and show how you can create a WCF server that provides an HTTP Polling Duplex binding that a Silverlight client can consume. What is HTTP Polling Duplex? Technologies that allow data to be pushed from a server to a client rely on duplex functionality. Duplex (or bi-directional) communication allows data to be passed in both directions. A client can call a service and the server can call the client. HTTP Polling Duplex (as its name implies) allows a server to communicate with a client without forcing the client to constantly poll the server. It has the benefit of being able to run on port 80 making setup a breeze compared to the other options which require specific ports to be used and cross-domain policy files to be exposed on port 943 (as with sockets and TCP bindings). Having said that, if you’re looking for the best speed possible then sockets and TCP bindings are the way to go. But, they’re not the only game in town when it comes to duplex communication. The first time I heard about HTTP Polling Duplex (initially available in Silverlight 2) I wasn’t exactly sure how it was any better than standard polling used in AJAX applications. I read the Silverlight SDK, looked at various resources and generally found the following definition unhelpful as far as understanding the actual benefits that HTTP Polling Duplex provided: "The Silverlight client periodically polls the service on the network layer, and checks for any new messages that the service wants to send on the callback channel. The service queues all messages sent on the client callback channel and delivers them to the client when the client polls the service." Although the previous definition explained the overall process, it sounded as if standard polling was used. Fortunately, Microsoft’s Scott Guthrie provided me with a more clear definition several years back that explains the benefits provided by HTTP Polling Duplex quite well (used with his permission): "The [HTTP Polling Duplex] duplex support does use polling in the background to implement notifications – although the way it does it is different than manual polling. It initiates a network request, and then the request is effectively “put to sleep” waiting for the server to respond (it doesn’t come back immediately). The server then keeps the connection open but not active until it has something to send back (or the connection times out after 90 seconds – at which point the duplex client will connect again and wait). This way you are avoiding hitting the server repeatedly – but still get an immediate response when there is data to send." After hearing Scott’s definition the light bulb went on and it all made sense. A client makes a request to a server to check for changes, but instead of the request returning immediately, it parks itself on the server and waits for data. It’s kind of like waiting to pick up a pizza at the store. Instead of calling the store over and over to check the status, you sit in the store and wait until the pizza (the request data) is ready. Once it’s ready you take it back home (to the client). This technique provides a lot of efficiency gains over standard polling techniques even though it does use some polling of its own as a request is initially made from a client to a server. So how do you implement HTTP Polling Duplex in your Silverlight applications? Let’s take a look at the process by starting with the server. Creating an HTTP Polling Duplex WCF Service Creating a WCF service that exposes an HTTP Polling Duplex binding is straightforward as far as coding goes. Add some one way operations into an interface, create a client callback interface and you’re ready to go. The most challenging part comes into play when configuring the service to properly support the necessary binding and that’s more of a cut and paste operation once you know the configuration code to use. To create an HTTP Polling Duplex service you’ll need to expose server-side and client-side interfaces and reference the System.ServiceModel.PollingDuplex assembly (located at C:\Program Files (x86)\Microsoft SDKs\Silverlight\v4.0\Libraries\Server on my machine) in the server project. For the demo application I upgraded a basketball simulation service to support the latest polling duplex assemblies. The service simulates a simple basketball game using a Game class and pushes information about the game such as score, fouls, shots and more to the client as the game changes over time. Before jumping too far into the game push service, it’s important to discuss two interfaces used by the service to communicate in a bi-directional manner. The first is called IGameStreamService and defines the methods/operations that the client can call on the server (see Listing 1). The second is IGameStreamClient which defines the callback methods that a server can use to communicate with a client (see Listing 2). [ServiceContract(Namespace = "Silverlight", CallbackContract = typeof(IGameStreamClient))] public interface IGameStreamService { [OperationContract(IsOneWay = true)] void GetTeamData(); } Listing 1. The IGameStreamService interface defines server operations that can be called on the server. [ServiceContract] public interface IGameStreamClient { [OperationContract(IsOneWay = true)] void ReceiveTeamData(List<Team> teamData); [OperationContract(IsOneWay = true, AsyncPattern=true)] IAsyncResult BeginReceiveGameData(GameData gameData, AsyncCallback callback, object state); void EndReceiveGameData(IAsyncResult result); } Listing 2. The IGameStreamClient interfaces defines client operations that a server can call. The IGameStreamService interface is decorated with the standard ServiceContract attribute but also contains a value for the CallbackContract property. This property is used to define the interface that the client will expose (IGameStreamClient in this example) and use to receive data pushed from the service. Notice that each OperationContract attribute in both interfaces sets the IsOneWay property to true. This means that the operation can be called and passed data as appropriate, however, no data will be passed back. Instead, data will be pushed back to the client as it’s available. Looking through the IGameStreamService interface you can see that the client can request team data whereas the IGameStreamClient interface allows team and game data to be received by the client. One interesting point about the IGameStreamClient interface is the inclusion of the AsyncPattern property on the BeginReceiveGameData operation. I initially created this operation as a standard one way operation and it worked most of the time. However, as I disconnected clients and reconnected new ones game data wasn’t being passed properly. After researching the problem more I realized that because the service could take up to 7 seconds to return game data, things were getting hung up. By setting the AsyncPattern property to true on the BeginReceivedGameData operation and providing a corresponding EndReceiveGameData operation I was able to get around this problem and get everything running properly. I’ll provide more details on the implementation of these two methods later in this post. Once the interfaces were created I moved on to the game service class. The first order of business was to create a class that implemented the IGameStreamService interface. Since the service can be used by multiple clients wanting game data I added the ServiceBehavior attribute to the class definition so that I could set its InstanceContextMode to InstanceContextMode.Single (in effect creating a Singleton service object). Listing 3 shows the game service class as well as its fields and constructor. [ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Multiple, InstanceContextMode = InstanceContextMode.Single)] public class GameStreamService : IGameStreamService { object _Key = new object(); Game _Game = null; Timer _Timer = null; Random _Random = null; Dictionary<string, IGameStreamClient> _ClientCallbacks = new Dictionary<string, IGameStreamClient>(); static AsyncCallback _ReceiveGameDataCompleted = new AsyncCallback(ReceiveGameDataCompleted); public GameStreamService() { _Game = new Game(); _Timer = new Timer { Enabled = false, Interval = 2000, AutoReset = true }; _Timer.Elapsed += new ElapsedEventHandler(_Timer_Elapsed); _Timer.Start(); _Random = new Random(); }} Listing 3. The GameStreamService implements the IGameStreamService interface which defines a callback contract that allows the service class to push data back to the client. By implementing the IGameStreamService interface, GameStreamService must supply a GetTeamData() method which is responsible for supplying information about the teams that are playing as well as individual players. GetTeamData() also acts as a client subscription method that tracks clients wanting to receive game data. Listing 4 shows the GetTeamData() method. public void GetTeamData() { //Get client callback channel var context = OperationContext.Current; var sessionID = context.SessionId; var currClient = context.GetCallbackChannel<IGameStreamClient>(); context.Channel.Faulted += Disconnect; context.Channel.Closed += Disconnect; IGameStreamClient client; if (!_ClientCallbacks.TryGetValue(sessionID, out client)) { lock (_Key) { _ClientCallbacks[sessionID] = currClient; } } currClient.ReceiveTeamData(_Game.GetTeamData()); //Start timer which when fired sends updated score information to client if (!_Timer.Enabled) { _Timer.Enabled = true; } } Listing 4. The GetTeamData() method subscribes a given client to the game service and returns. The key the line of code in the GetTeamData() method is the call to GetCallbackChannel<IGameStreamClient>(). This method is responsible for accessing the calling client’s callback channel. The callback channel is defined by the IGameStreamClient interface shown earlier in Listing 2 and used by the server to communicate with the client. Before passing team data back to the client, GetTeamData() grabs the client’s session ID and checks if it already exists in the _ClientCallbacks dictionary object used to track clients wanting callbacks from the server. If the client doesn’t exist it adds it into the collection. It then pushes team data from the Game class back to the client by calling ReceiveTeamData(). Since the service simulates a basketball game, a timer is then started if it’s not already enabled which is then used to randomly send data to the client. When the timer fires, game data is pushed down to the client. Listing 5 shows the _Timer_Elapsed() method that is called when the timer fires as well as the SendGameData() method used to send data to the client. void _Timer_Elapsed(object sender, ElapsedEventArgs e) { int interval = _Random.Next(3000, 7000); lock (_Key) { _Timer.Interval = interval; _Timer.Enabled = false; } SendGameData(_Game.GetGameData()); } private void SendGameData(GameData gameData) { var cbs = _ClientCallbacks.Where(cb => ((IContextChannel)cb.Value).State == CommunicationState.Opened); for (int i = 0; i < cbs.Count(); i++) { var cb = cbs.ElementAt(i).Value; try { cb.BeginReceiveGameData(gameData, _ReceiveGameDataCompleted, cb); } catch (TimeoutException texp) { //Log timeout error } catch (CommunicationException cexp) { //Log communication error } } lock (_Key) _Timer.Enabled = true; } private static void ReceiveGameDataCompleted(IAsyncResult result) { try { ((IGameStreamClient)(result.AsyncState)).EndReceiveGameData(result); } catch (CommunicationException) { // empty } catch (TimeoutException) { // empty } } LIsting 5. _Timer_Elapsed is used to simulate time in a basketball game. When _Timer_Elapsed() fires the SendGameData() method is called which iterates through the clients wanting to be notified of changes. As each client is identified, their respective BeginReceiveGameData() method is called which ultimately pushes game data down to the client. Recall that this method was defined in the client callback interface named IGameStreamClient shown earlier in Listing 2. Notice that BeginReceiveGameData() accepts _ReceiveGameDataCompleted as its second parameter (an AsyncCallback delegate defined in the service class) and passes the client callback as the third parameter. The initial version of the sample application had a standard ReceiveGameData() method in the client callback interface. However, sometimes the client callbacks would work properly and sometimes they wouldn’t which was a little baffling at first glance. After some investigation I realized that I needed to implement an asynchronous pattern for client callbacks to work properly since 3 – 7 second delays are occurring as a result of the timer. Once I added the BeginReceiveGameData() and ReceiveGameDataCompleted() methods everything worked properly since each call was handled in an asynchronous manner. The final task that had to be completed to get the server working properly with HTTP Polling Duplex was adding configuration code into web.config. In the interest of brevity I won’t post all of the code here since the sample application includes everything you need. However, Listing 6 shows the key configuration code to handle creating a custom binding named pollingDuplexBinding and associate it with the service’s endpoint. <bindings> <customBinding> <binding name="pollingDuplexBinding"> <binaryMessageEncoding /> <pollingDuplex maxPendingSessions="2147483647" maxPendingMessagesPerSession="2147483647" inactivityTimeout="02:00:00" serverPollTimeout="00:05:00"/> <httpTransport /> </binding> </customBinding> </bindings> <services> <service name="GameService.GameStreamService" behaviorConfiguration="GameStreamServiceBehavior"> <endpoint address="" binding="customBinding" bindingConfiguration="pollingDuplexBinding" contract="GameService.IGameStreamService"/> <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" /> </service> </services> Listing 6. Configuring an HTTP Polling Duplex binding in web.config and associating an endpoint with it. Calling the Service and Receiving “Pushed” Data Calling the service and handling data that is pushed from the server is a simple and straightforward process in Silverlight. Since the service is configured with a MEX endpoint and exposes a WSDL file, you can right-click on the Silverlight project and select the standard Add Service Reference item. After the web service proxy is created you may notice that the ServiceReferences.ClientConfig file only contains an empty configuration element instead of the normal configuration elements created when creating a standard WCF proxy. You can certainly update the file if you want to read from it at runtime but for the sample application I fed the service URI directly to the service proxy as shown next: var address = new EndpointAddress("http://localhost.:5661/GameStreamService.svc"); var binding = new PollingDuplexHttpBinding(); _Proxy = new GameStreamServiceClient(binding, address); _Proxy.ReceiveTeamDataReceived += _Proxy_ReceiveTeamDataReceived; _Proxy.ReceiveGameDataReceived += _Proxy_ReceiveGameDataReceived; _Proxy.GetTeamDataAsync(); This code creates the proxy and passes the endpoint address and binding to use to its constructor. It then wires the different receive events to callback methods and calls GetTeamDataAsync(). Calling GetTeamDataAsync() causes the server to store the client in the server-side dictionary collection mentioned earlier so that it can receive data that is pushed. As the server-side timer fires and game data is pushed to the client, the user interface is updated as shown in Listing 7. Listing 8 shows the _Proxy_ReceiveGameDataReceived() method responsible for handling the data and calling UpdateGameData() to process it. Listing 7. The Silverlight interface. Game data is pushed from the server to the client using HTTP Polling Duplex. void _Proxy_ReceiveGameDataReceived(object sender, ReceiveGameDataReceivedEventArgs e) { UpdateGameData(e.gameData); } private void UpdateGameData(GameData gameData) { //Update Score this.tbTeam1Score.Text = gameData.Team1Score.ToString(); this.tbTeam2Score.Text = gameData.Team2Score.ToString(); //Update ball visibility if (gameData.Action != ActionsEnum.Foul) { if (tbTeam1.Text == gameData.TeamOnOffense) { AnimateBall(this.BB1, this.BB2); } else //Team 2 { AnimateBall(this.BB2, this.BB1); } } if (this.lbActions.Items.Count > 9) this.lbActions.Items.Clear(); this.lbActions.Items.Add(gameData.LastAction); if (this.lbActions.Visibility == Visibility.Collapsed) this.lbActions.Visibility = Visibility.Visible; } private void AnimateBall(Image onBall, Image offBall) { this.FadeIn.Stop(); Storyboard.SetTarget(this.FadeInAnimation, onBall); Storyboard.SetTarget(this.FadeOutAnimation, offBall); this.FadeIn.Begin(); } Listing 8. As the server pushes game data, the client’s _Proxy_ReceiveGameDataReceived() method is called to process the data. In a real-life application I’d go with a ViewModel class to handle retrieving team data, setup data bindings and handle data that is pushed from the server. However, for the sample application I wanted to focus on HTTP Polling Duplex and keep things as simple as possible. Summary Silverlight supports three options when duplex communication is required in an application including TCP bindins, sockets and HTTP Polling Duplex. In this post you’ve seen how HTTP Polling Duplex interfaces can be created and implemented on the server as well as how they can be consumed by a Silverlight client. HTTP Polling Duplex provides a nice way to “push” data from a server while still allowing the data to flow over port 80 or another port of your choice. Sample Application Download

Read the article

It's the End of the Life as We Know It and Linux Feels Fine

<b>IT World:</b> "Since we live in an entropic universe, things end. Heady stuff for a Monday morning, I will admit, but just keep drinking that coffee, you'll catch up."

Read the article

Generate DROP statements for all extended properties

- by jamiet

This evening I have been attempting to migrate an existing on-premise database to SQL Azure using the wizard that is built-in to SQL Server Management Studio (SSMS). When I did so I received the following error: The following objects are not supported = [MS_Description] = Extended Property Evidently databases containing extended properties can not be migrated using this particular wizard so I set about removing all of the extended properties – unfortunately there were over a thousand of them so I needed a better way than simply deleting each and every one of them manually. I found a couple of resources online that went some way toward this: Drop all extended properties in a MSSQL database by Angelo Hongens Modifying and deleting extended properties by Adam Aspin Unfortunately neither provided a script that exactly suited my needs. Angelo’s covered extended properties on tables and columns however I had other objects that had extended properties on them. Adam’s looked more complete but when I ran it I got an error: Msg 468, Level 16, State 9, Line 78 Cannot resolve the collation conflict between "Latin1_General_100_CS_AS" and "Latin1_General_CI_AS" in the equal to operation. So, both great resources but I wasn’t able to use either on their own to get rid of all of my extended properties. Hence, I combined the excellent work that Angelo and Adam had provided in order to manufacture my own script which did successfully manage to generate calls to sp_dropextendedproperty for all of my extended properties. If you think you might be able to make use of such a script then feel free to download it from https://skydrive.live.com/redir.aspx?cid=550f681dad532637&resid=550F681DAD532637!16707&parid=550F681DAD532637!16706&authkey=!APxPIQCatzC7BQ8. This script will remove extended properties on tables, columns, check constraints, default constraints, views, sprocs, foreign keys, primary keys, table triggers, UDF parameters, sproc parameters, databases, schemas, database files and filegroups. If you have any object types with extended properties on them that are not in that list then consult Adam’s aforementioned article – it should prove very useful. I repeat here the message that I have placed at the top of the script: /* This script will generate calls to sp_dropextendedproperty for every extended property that exists in your database. Actually, a caveat: I don't promise that it will catch each and every extended property that exists, but I'm confident it will catch most of them! It is based on this: http://blog.hongens.nl/2010/02/25/drop-all-extended-properties-in-a-mssql-database/ by Angelo Hongens. Also had lots of help from this: http://www.sqlservercentral.com/articles/Metadata/72609/ by Adam Aspin Adam actually provides a script at that link to do something very similar but when I ran it I got an error: Msg 468, Level 16, State 9, Line 78 Cannot resolve the collation conflict between "Latin1_General_100_CS_AS" and "Latin1_General_CI_AS" in the equal to operation. So I put together this version instead. Use at your own risk. Jamie Thomson 2012-03-25 */ Hope this is useful to someone! @Jamiet

Read the article

View Clipboard & Copy To Clipboard from NetBeans IDE

- by Geertjan

Thanks to this code, I can press Ctrl-Alt-V in NetBeans IDE and then view whatever is in the clipboard: import java.awt.Toolkit; import java.awt.datatransfer.DataFlavor; import java.awt.datatransfer.Transferable; import java.awt.datatransfer.UnsupportedFlavorException; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.IOException; import javax.swing.JOptionPane; import org.openide.awt.ActionRegistration; import org.openide.awt.ActionReference; import org.openide.awt.ActionReferences; import org.openide.awt.ActionID; import org.openide.util.NbBundle.Messages; @ActionID( category = "Tools", id = "org.demo.ShowClipboardAction") @ActionRegistration( displayName = "#CTL_ShowClipboardAction") @ActionReferences({ @ActionReference(path = "Menu/Tools", position = 5), @ActionReference(path = "Shortcuts", name = "DA-V") }) @Messages("CTL_ShowClipboardAction=Show Clipboard") public final class ShowClipboardAction implements ActionListener { @Override public void actionPerformed(ActionEvent e) { JOptionPane.showMessageDialog(null, getClipboard(), "Clipboard Content", 1); } public String getClipboard() { String text = null; Transferable t = Toolkit.getDefaultToolkit().getSystemClipboard().getContents(null); try { if (t != null && t.isDataFlavorSupported(DataFlavor.stringFlavor)) { text = (String) t.getTransferData(DataFlavor.stringFlavor); } } catch (UnsupportedFlavorException e) { } catch (IOException e) { } return text; } } And now I can also press Ctrl-Alt-C, which copies the path to the current file to the clipboard: import java.awt.Toolkit; import java.awt.datatransfer.Clipboard; import java.awt.datatransfer.StringSelection; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import org.openide.awt.ActionID; import org.openide.awt.ActionReference; import org.openide.awt.ActionReferences; import org.openide.awt.ActionRegistration; import org.openide.awt.StatusDisplayer; import org.openide.loaders.DataObject; import org.openide.util.NbBundle.Messages; @ActionID( category = "Tools", id = "org.demo.CopyPathToClipboard") @ActionRegistration( displayName = "#CTL_CopyPathToClipboard") @ActionReferences({ @ActionReference(path = "Menu/Tools", position = 0), @ActionReference(path = "Editors/Popup", position = 10), @ActionReference(path = "Shortcuts", name = "DA-C") }) @Messages("CTL_CopyPathToClipboard=Copy Path to Clipboard") public final class CopyPathToClipboardAction implements ActionListener { private final DataObject context; public CopyPathToClipboardAction(DataObject context) { this.context = context; } @Override public void actionPerformed(ActionEvent e) { String path = context.getPrimaryFile().getPath(); StatusDisplayer.getDefault().setStatusText(path); StringSelection ss = new StringSelection(path); Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard(); clipboard.setContents(ss, null); } }

Read the article

Oracle ADF Sessions at Oracle OpenWorld LAD This Week

- by shay.shmeltzer

If you are attending Oracle OpenWorld/Oracle Develop/JavaOne in Sao Paulo Brazil this week, there are a few sessions dedicated to ADF that you might want to catch,Wed 3:45 S316863 An Introduction to Oracle Application Development Framework Task Flows (Salon 9)Wed 6:00pm An ADF Hands-on Lab: S318563 Oracle Fusion Applications Development Experience: An Oracle ADF Overview (Salon 7)Thu 5:15 S316857 Accelerated Java EE Development: The Oracle Way (Salon 9)And don't forget the JDeveloper booth at the JavaOne Demoground area.See you there.

Search Results

Search found 6686 results on 268 pages for 'liston catch'.

Page 53/268 | < Previous Page | 49 50 51 52 53 54 55 56 57 58 59 60 | Next Page >

- by Costa

- by mr popo

- by Duncan Palmer

- by kevdliu

- by daemon_x

- by Nitesh Panchal

- by fuch

- by oudouz

- by kate

- by doele

- by giant91

- by user2785137

- by Nitesh Panchal

- by Rick Strahl

- by Reed

- by Brian Schroer

- by subodhnpushpak

- by Kavitha

- by KKline

- by Jani Rautiainen

- by dwahlin

- by jamiet

- by Geertjan

- by shay.shmeltzer

< Previous Page | 49 50 51 52 53 54 55 56 57 58 59 60 | Next Page >