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  • extend web server to serve static files

    - by Turtle
    Hello, I want to extend a web server which is only able to handle RPC handling now. The web server is written in C#. It provides a abstract handler function like following: public string owsHandler(string request, string path, string param, OSHttpRequest httpRequest, OSHttpResponse httpResponse) And I wrote following code to handle image files: Bitmap queryImg = new Bitmap(path); System.IO.MemoryStream stream = new System.IO.MemoryStream(); queryImg.Save(stream, System.Drawing.Imaging.ImageFormat.Bmp); queryImg.Dispose(); byte[] byteImage = stream.ToArray(); stream.Dispose(); return Convert.ToBase64String(byteImage); And I test it in the browser, the image is returned but the image dimension info is missed. Shall I add something more to the code? Or is any general way to server static files? I do not want to serve it in a ASP.net server. Thanks

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  • Why compiler go to suspend mode when want to open database?

    - by rima
    Dear friend I try to connect to database with a less line for my connection string... I find out s.th in oracle website but i dont know Why when the compiler arrive to the line of open database do nothing????!it go back to GUI,but it like hanging...please help me to solve it. p.s.Its funny the program didnt get me any exception also! these service is active in my computer: > Oracle ORCL VSS Writer Service Start > OracleDBConsolrorcl > OracleJobSchedulerORCL Start > OracleOraDB11g+home1TNSListener Start > oracleServiceORCL Start try { /** * ORCL = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = rima-PC)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl) ) )*/ string oradb = "Data Source=(DESCRIPTION=" + "(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=rima-PC)(PORT=1521)))" + "(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=orcl)));" + "User Id=bird_artus;Password=123456;"; //string oradb = "Data Source=OraDb;User Id=scott;Password=tiger;"; string oradb1 = "Data Source=ORCL;User Id=scott;Password=tiger;"; // C# OracleConnection con = new OracleConnection(); con.ConnectionString = oradb1; String command = "select dname from dept where deptno = 10"; MessageBox.Show(command); OracleDataAdapter oda = new OracleDataAdapter(); oda.SelectCommand = new OracleCommand(); oda.SelectCommand.Connection = con; oda.SelectCommand.CommandText = command; con.Open(); oda.SelectCommand.ExecuteNonQuery(); DataSet ds = new DataSet(); oda.Fill(ds); Console.WriteLine(ds.GetXml()); dataGridView1.DataSource = ds; con.Close(); } catch (Exception ex) { MessageBox.Show(ex.Message.ToString()+Environment.NewLine+ ex.StackTrace.ToString()); }

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  • ProtoInclude for fields ?

    - by Big
    I have a simple object [ProtoContract] public class DataChangedEventArgs<T> : EventArgs { private readonly object key; private readonly T data; private readonly DataChangeType changeType; ///<summary> /// Key to identify the data item ///</summary> public object Key { get { return key; } } [ProtoMember(2, IsRequired = true)] public T Data { get { return data; } } [ProtoMember(3, IsRequired = true)] public DataChangeType ChangeType { get { return changeType; } } and I have a problem with the key. Its type is object, but it can be either int, long or string. I would intuitively use a ProtoInclude attribute to say "expect these types" but unfortunately they are class only attribute. Does anybody has any idea how I could work around this ? For background, the public object Key is here for historical reasons (and all over the place) so I would very much like to avoid the mother of all refactorings ;-) Any chance I could get this to Serialize, even force it to Serialize as a string ?

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  • How to sort a list in Scala by two fields?

    - by Twistleton
    how to sort a list in Scala by two fields, in this example I will sort by lastName and firstName? case class Row(var firstName: String, var lastName: String, var city: String) var rows = List(new Row("Oscar", "Wilde", "London"), new Row("Otto", "Swift", "Berlin"), new Row("Carl", "Swift", "Paris"), new Row("Hans", "Swift", "Dublin"), new Row("Hugo", "Swift", "Sligo")) rows.sortBy(_.lastName) I try things like this rows.sortBy(_.lastName + _.firstName) but it doesn't work. So I be curious for a good and easy solution. Thanks in advance! Pongo

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  • Axis webservice calls fail sometimes, access.log shows content!

    - by epischel
    Hi, our app is a webservice client (axis 1) to a third party webservice (also axis 1). We use it for some years now. Since a few weeks, we (as a client) get sometimes HTTP status 400 (bad request) or read timeouts when calling the webservice. Strangely, the access.log of the service shows part of the request or the response instead of the URL. It looks like this (looks like the end of the request string) x.x.x.x -> y.y.y.y:8080 - - [timestamp] "POST /webservice HTTP/1.0" 200 16127 0 x.x.x.x -> y.y.y.y:8080 - - [timestamp] "POST /webservice HTTP/1.0" 200 22511 1 x.x.x.x -> y.y.y.y:8080 - - [timestamp] "il=\"true\"/><nsl:text xsi:type=\"xsd:string\" xsi:nil=\"true\"/></SOAPSomeOperation></soapenv:Body></soapenv:Envelope> Axis/1.4" 400 299 0 or (some string out of the what looks like the request) x.x.x.x -> y.y.y.y:8080 - - [timestamp] ":string\">some text</sometag><othertag>moretext" 400 299 0 or in some other cases it looks like two requests thrown together (... means xml string left out): x.x.x.x -> y.y.y.y:8080 - - [timestamp] "...</someop></soapenv:Body></soapenv:Envelope>:xsd=\"http://www.w3.org/2001/XMLSchema\"...</soapenv:Body></soapenv:Envelope>" 400 299 0 Application log does not give any hints. Frequency of such call is 1% of all calls to that service. The only discriminator I know of so far is that it happens since operations informed us that the service url changed because of "server migration". Has anyone experienced such phenomenon yet? Has somebody got an idea whats wrong and how to fix? Thanks,

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  • SQLiteDataAdapter Update method returning 0

    - by Lirik
    I loaded 83 rows from my CSV file, but when I try to update the SQLite database I get 0 rows... I can't figure out what I'm doing wrong. The program outputs: Num rows loaded is 83 Num rows updated is 0 The source code is: public void InsertData(String csvFileName, String tableName) { String dir = Path.GetDirectoryName(csvFileName); String name = Path.GetFileName(csvFileName); using (OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dir + @";Extended Properties=""Text;HDR=Yes;FMT=Delimited""")) { conn.Open(); using (OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * FROM " + name, conn)) { QuoteDataSet ds = new QuoteDataSet(); adapter.Fill(ds, tableName); Console.WriteLine("Num rows loaded is " + ds.Tags.Rows.Count); InsertData(ds, tableName); } } } public void InsertData(QuoteDataSet data, String tableName) { using (SQLiteConnection conn = new SQLiteConnection(_connectionString)) { using (SQLiteDataAdapter sqliteAdapter = new SQLiteDataAdapter("SELECT * FROM " + tableName, conn)) { using (new SQLiteCommandBuilder(sqliteAdapter)) { conn.Open(); Console.WriteLine("Num rows updated is " + sqliteAdapter.Update(data, tableName)); } } } } Any hints on why it's not updating the correct number of rows?

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  • DataGridView and Binding List Event.

    - by bearrito
    I have a datagridview with a datasource of type binding list. I understand that when the datagridview changed this will update the items in the binding list. I also know that if the objects in the bindinglist implement Inotifypropertychanged then if the obects are changed outside the grid then the objects will notify the bindlist which will then notify the datagrid My question is: If the datagrid view changing an object, I want the bindinglist or changed object to fire an event that allows me to pass the object to a WCF service that will persist the object on the data access layer side e.g. Service.Save(ChangedObject) How would I go about doing this?

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  • Implements an Undo/Redo in MVC

    - by bnabilos
    Hello, I have a Java application and I want to implement an Undo/Redo option. the value that I want to stock and that I want to be able to recover is an integer. My Class Model implements the interface StateEditable and I have to redefine the 2 functions restoreState(Hashtable<?, ?> state) and storeState(Hashtable<Object, Object> state) but I don't know what to put on them. It will be really great if somebody can help me to do that. These are the first lines of my Model class, the value that I want to do an undo/redo on it is value public class Model extends Observable implements StateEditable { private int value = 5; private UndoManager undoRedo = new UndoManager(); final UndoableEditListener editListener = new UndoableEditListener() { public void undoableEditHappened(UndoableEditEvent evt) { undoRedo.addEdit(evt.getEdit()); } }; @Override public void restoreState(Hashtable<?, ?> state) { } @Override public void storeState(Hashtable<Object, Object> state) { } }

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  • ERROR_MORE_DATA ---- Reading from Registry

    - by user314749
    I am trying to create an offline registry in memory using the offreg.dll provided in the windows ddk 7 package. You can find out more information on the offreg.dll here: MSDN Currently, while attempting to read a value from an open registry hive / key I receive the following error: 234 or ERROR_MORE_DATA Here is the .h code that contains ORGetValue: DWORD ORAPI ORGetValue ( __in ORHKEY Handle, __in_opt PCWSTR lpSubKey, __in_opt PCWSTR lpValue, __out_opt PDWORD pdwType, __out_bcount_opt(*pcbData) PVOID pvData, __inout_opt PDWORD pcbData ); Here is the code that I am using to pull the data [DllImport("offreg.dll", CharSet = CharSet.Auto, EntryPoint = "ORGetValue", SetLastError = true, CallingConvention = CallingConvention.StdCall)] public static extern uint ORGetValue(IntPtr Handle, string lpSubKey, string lpValue, out uint pdwType, out string pvData, out uint pcbData); IntPtr myHive; IntPtr myKey; string myValue; uint pdwtype; uint pcbdata; uint ret3 = ORGetValue(myKey, "", "DefaultUserName", out pdwtype, out myValue, out pcbdata); The goal is to be able to read myValue as a string. I am not sure if I need to use marshaling... or a second call with an adjusted buffer.. Or really how to adjust the buffer in C#. Any help or pointers would be greatly appreciated. Thank you.

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  • WMS authentication plugin

    - by roul
    Hi, I'm trying to create a custom authentication plugin for WMS 2009 in C#. I managed to implement something that for some reason blocks all requests... [ComVisible(true)] [Guid("C0A0B38C-C4FE-43B5-BE9E-C100A83BBCEE")] public class AuthenticationPlugin : IWMSBasicPlugin, IWMSAuthenticationPlugin, IWMSAuthenticationContext private const string SubKey = "SOFTWARE\\Microsoft\\Windows Media\\Server\\RegisteredPlugins\\Authentication\\{C0A0B38C-C4FE-43B5-BE9E-C100A83BBCEE}"; [ComRegisterFunction] public static void RegisterFunction(Type t) { try { RegistryKey regHKLM = Registry.LocalMachine; regHKLM = regHKLM.CreateSubKey(SubKey); regHKLM.SetValue(null, "UC WMS Authentication plugin"); RegistryKey regHKCR = Registry.ClassesRoot; regHKCR = regHKCR.CreateSubKey("CLSID\\{C0A0B38C-C4FE-43B5-BE9E-C100A83BBCEE}\\Properties"); regHKCR.SetValue("Name", CustomC WMS Authentication plugin"); regHKCR.SetValue("Author", "Me"); regHKCR.SetValue("CopyRight", "Copyright 2009. All rights reserved"); regHKCR.SetValue("Description", "Enables custom WMS authentication"); } catch (Exception error) { Console.WriteLine(error.Message, "Inside RegisterFunction(). Cannot Register."); } } [ComUnregisterFunction] public static void UnRegisterFunction(Type t) { try { RegistryKey regHKLM = Registry.LocalMachine; regHKLM.DeleteSubKey(SubKey); RegistryKey regHKCR = Registry.ClassesRoot; regHKCR.DeleteSubKeyTree("CLSID\\{C0A0B38C-C4FE-43B5-BE9E-C100A83BBCEE}"); regHKCR.DeleteSubKeyTree("CSEventTest.CSEventPlugin"); } catch (Exception error) { Console.WriteLine(error.Message, "Cannot delete a subkey."); } } #region IWMSBasicPlugin Members public void InitializePlugin(IWMSContext serverContext, WMSNamedValues namedValues, IWMSClassObject classFactory) { } public void ShutdownPlugin() { } public void EnablePlugin(ref int flags, ref int heartbeatPeriod) { } public void DisablePlugin() { } public object GetCustomAdminInterface() { return null; } public void OnHeartbeat() { } #endregion #region IWMSAuthenticationPlugin Members public IWMSAuthenticationContext CreateAuthenticationContext() { return (IWMSAuthenticationContext)this; } public int GetFlags() { return Convert.ToInt32(WMS_AUTHENTICATION_FLAGS.WMS_AUTHENTICATION_ANONYMOUS, CultureInfo.InvariantCulture); } public string GetPackageName() { return "Custom WMS Authentication"; } public string GetProtocolName() { return "Basic"; } #endregion #region IWMSAuthenticationContext Members public void Authenticate(object responseBlob, IWMSContext userContext, IWMSContext presentationContext, IWMSCommandContext commandContext, IWMSAuthenticationCallback callBack, object context) { callBack.OnAuthenticateComplete(WMS_AUTHENTICATION_RESULT.WMS_AUTHENTICATION_SUCCESS, null, context); } public IWMSAuthenticationPlugin GetAuthenticationPlugin() { return (IWMSAuthenticationPlugin)this; } public string GetImpersonationAccountName() { return String.Empty; } public int GetImpersonationToken() { return 0; } public string GetLogicalUserID() { return this.GetImpersonationAccountName(); } #endregion } Can anyone spot why this is happening? Also, is there any way I could have a look at the code for the standard Anonymous Authentication plugin already installed on the server? Is it in an assembly somewhere? Thanks.

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  • Problems with list<T> in Asp.Net c#

    - by Johnathan Nardia
    I'm making a web app in Asp.Net using c# that lets you add items into the list. My problem is that each time that i click the button to add a new item into the list , its just shows me the last item and the list counter shows me only 1 . What am I doing wrong?? Here is the code : public partial class home : System.Web.UI.Page { List<string> messageboxs = new List<string>(); public string val = ""; public string data = ""; protected void Button1_Click(object sender, EventArgs e) { val = ""; messageboxs.Add(text1.Text); ListBox1.DataSource = messageboxs; ListBox1.DataBind(); val = messageboxs.Count.ToString(); } }

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  • JSF 2 f:ajax lifecycle problem

    - by gerry
    The problem is, that if a property is changed during an f:ajax request and a binded panelGroup should be newly created depending on that changed value, the old value is used. This code will explain the problem. Here is the backingbean TestBean: public String getFirst() { return first; } public void setFirst(String first) { this.first = first; } public String getLast() { return last; } public void setLast(String last) { this.last = last; } public String getName(){ return first+" "+last; } public void setDynamicPanel(HtmlPanelGroup panel){ } public HtmlPanelGroup getDynamicPanel(){ Application app = FacesContext.getCurrentInstance().getApplication(); HtmlPanelGroup component = (HtmlPanelGroup)app.createComponent(HtmlPanelGroup.COMPONENT_TYPE); HtmlOutputLabel label1 = (HtmlOutputLabel)app.createComponent(HtmlOutputLabel.COMPONENT_TYPE); label1.setValue(" --> "+getFirst()+" "+getLast()); component.getChildren().add(label1); return component; } and now the jsf/facelet code: <h:form id="form"> <h:panelGrid columns="1"> <h:inputText id="first" value="#{testBean.first}" /> <h:inputText id="last" value="#{testBean.last}" /> <h:commandButton value="Show"> <f:ajax execute="first last" render="name dyn" /> </h:commandButton> </h:panelGrid> <h:outputText id="name" value="#{testBean.name}" /> <h:panelGroup id="dyn" binding="#{testBean.dynamicPanel}" /> </h:form> After the page was initially loaded the outputText and panelGroup shows both "null" as first and last. But after the button is pressed, the outputText is updated well, but the the panelgroup shows again only "null". This is due to the problem, that the "binded method" dynamicPanel is executed before the update of the first and last properties. how can workaround this behaviour or what is wrong with my code?

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  • Regex help in java validations

    - by user1697113
    Hi i want to do some validations.I used to put regex in JS but im new to regex in java, so i tried to make up a code on similar lines in java. Here is what i did. 1)Check whether first character in string is alphanumeric. 2)Check whether the string atleast 1 number. so i wrote a code, but it is always returning false.I am not sure if i'm doing this correctly. private static boolean checkEmbeddedPassword(final String field) { boolean returnValue=true; String testpatternAlpha="/^[A-Za-z0-9].+$/"; String testNumber="/[0-9]/"; Pattern pattern=Pattern.compile(testpatternAlpha); Pattern pattern2=Pattern.compile(testNumber); Matcher matcher = pattern.matcher(field); Matcher matcher2 = pattern2.matcher(field); boolean firstChar=matcher.matches(); boolean numberFlag=matcher2.matches(); System.out.println("-----the value of pwd iss-----"+field); System.out.println("---------Regex---------Out--put-----"+firstChar); System.out.println("---------Regex---------Out- for numeral-put-----"+numberFlag); if(firstChar){ returnValue=false; } else if(field.contains(" ")) { System.out.println("-----------cannot have space------"); returnValue=false; } else if(numberFlag) { returnValue=false; } return returnValue; }

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  • How to implement an EventHandler to update controls

    - by Bill
    May I ask for help with the following? I am attempting to connect and control three pieces of household electronic equipment by computer through a GlobalCache GC-100 and iTach. As you will see in the following code, I created a class-instance of GlobalCacheAdapter that communicates with each piece of equipment. Although the code seems to work well in controlling the equipment, I am having trouble updating controls with the feedback from the equipment. The procedure "ReaderThreadProc" captures the feedback; however I don't know how to update the associated TextBox with the feedback. I believe that I need to create an EventHandler to notify the TextBox of the available update; however I am uncertain as to how an EventHandler like this would be implemented. Any help wold be greatly appreciated. using System; using System.IO; using System.Net; using System.Net.Sockets; using System.Threading; using System.Windows.Forms; namespace WindowsFormsApplication1 { public partial class Form1 : Form { // Create three new instances of GlobalCacheAdaptor and connect. // GC-100 (Elan) 192.168.1.70 4998 // GC-100 (TuneSuite) 192.168.1.70 5000 // GC iTach (Lighting) 192.168.1.71 4999 private GlobalCacheAdaptor elanGlobalCacheAdaptor; private GlobalCacheAdaptor tuneSuiteGlobalCacheAdaptor; private GlobalCacheAdaptor lutronGlobalCacheAdaptor; public Form1() { InitializeComponent(); elanGlobalCacheAdaptor = new GlobalCacheAdaptor(); elanGlobalCacheAdaptor.ConnectToDevice(IPAddress.Parse("192.168.1.70"), 4998); tuneSuiteGlobalCacheAdaptor = new GlobalCacheAdaptor(); tuneSuiteGlobalCacheAdaptor.ConnectToDevice(IPAddress.Parse("192.168.1.70"), 5000); lutronGlobalCacheAdaptor = new GlobalCacheAdaptor(); lutronGlobalCacheAdaptor.ConnectToDevice(IPAddress.Parse("192.168.1.71"), 4999); elanTextBox.Text = elanGlobalCacheAdaptor._line; tuneSuiteTextBox.Text = tuneSuiteGlobalCacheAdaptor._line; lutronTextBox.Text = lutronGlobalCacheAdaptor._line; } private void btnZoneOnOff_Click(object sender, EventArgs e) { elanGlobalCacheAdaptor.SendMessage("sendir,4:3,1,40000,4,1,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,800" + Environment.NewLine); } private void btnSourceInput1_Click(object sender, EventArgs e) { elanGlobalCacheAdaptor.SendMessage("sendir,4:3,1,40000,1,1,20,179,20,179,20,179,20,179,20,179,20,179,20,179,20,278,20,179,20,179,20,179,20,780" + Environment.NewLine); } private void btnSystemOff_Click(object sender, EventArgs e) { elanGlobalCacheAdaptor.SendMessage("sendir,4:3,1,40000,1,1,20,184,20,184,20,184,20,184,20,184,20,286,20,286,20,286,20,184,20,184,20,184,20,820" + Environment.NewLine); } private void btnLightOff_Click(object sender, EventArgs e) { lutronGlobalCacheAdaptor.SendMessage("sdl,14,0,0,S2\x0d"); } private void btnLightOn_Click(object sender, EventArgs e) { lutronGlobalCacheAdaptor.SendMessage("sdl,14,100,0,S2\x0d"); } private void btnChannel31_Click(object sender, EventArgs e) { tuneSuiteGlobalCacheAdaptor.SendMessage("\xB8\x4D\xB5\x33\x31\x00\x30\x21\xB8\x0D"); } private void btnChannel30_Click(object sender, EventArgs e) { tuneSuiteGlobalCacheAdaptor.SendMessage("\xB8\x4D\xB5\x33\x30\x00\x30\x21\xB8\x0D"); } } } public class GlobalCacheAdaptor { public Socket _multicastListener; public string _preferredDeviceID; public IPAddress _deviceAddress; public Socket _deviceSocket; public StreamWriter _deviceWriter; public bool _isConnected; public int _port; public IPAddress _address; public string _line; public GlobalCacheAdaptor() { } public static readonly GlobalCacheAdaptor Instance = new GlobalCacheAdaptor(); public bool IsListening { get { return _multicastListener != null; } } public GlobalCacheAdaptor ConnectToDevice(IPAddress address, int port) { if (_deviceSocket != null) _deviceSocket.Close(); try { _port = port; _address = address; _deviceSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); _deviceSocket.Connect(new IPEndPoint(address, port)); ; _deviceAddress = address; var stream = new NetworkStream(_deviceSocket); var reader = new StreamReader(stream); var writer = new StreamWriter(stream) { NewLine = "\r", AutoFlush = true }; _deviceWriter = writer; writer.WriteLine("getdevices"); var readerThread = new Thread(ReaderThreadProc) { IsBackground = true }; readerThread.Start(reader); _isConnected = true; return Instance; } catch { DisconnectFromDevice(); MessageBox.Show("ConnectToDevice Error."); throw; } } public void SendMessage(string message) { try { var stream = new NetworkStream(_deviceSocket); var reader = new StreamReader(stream); var writer = new StreamWriter(stream) { NewLine = "\r", AutoFlush = true }; _deviceWriter = writer; writer.WriteLine(message); var readerThread = new Thread(ReaderThreadProc) { IsBackground = true }; readerThread.Start(reader); } catch { MessageBox.Show("SendMessage() Error."); } } public void DisconnectFromDevice() { if (_deviceSocket != null) { try { _deviceSocket.Close(); _isConnected = false; } catch { MessageBox.Show("DisconnectFromDevice Error."); } _deviceSocket = null; } _deviceWriter = null; _deviceAddress = null; } private void ReaderThreadProc(object state) { var reader = (StreamReader)state; try { while (true) { var line = reader.ReadLine(); if (line == null) break; _line = _line + line + Environment.NewLine; } // Need to create EventHandler to notify the TextBoxes to update with _line } catch { MessageBox.Show("ReaderThreadProc Error."); } } }

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  • How to use pure in D 2.0

    - by James Dean
    While playing around with D 2.0 I found the following problem: Example 1: pure string[] run1() { string[] msg; msg ~= "Test"; msg ~= "this."; return msg; } This compiles and works as expected. When I try to wrap the string array in a class I find I can not get this to work: class TestPure { string[] msg; void addMsg( string s ) { msg ~= s; } }; pure TestPure run2() { TestPure t = new TestPure(); t.addMsg("Test"); t.addMsg("this."); return t; } This code will not compile because the addMsg function is impure. I can not make that function pure since it alters the TestPure object. Am i missing something? Or is this a limitation? The following does compile: pure TestPure run3() { TestPure t = new TestPure(); t.msg ~= "Test"; t.msg ~= "this."; return t; } Would the ~= operator not been implemented as a impure function of the msg array? How come the compiler does not complain about that in the run1 function?

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  • Can you pass by reference in Java?

    - by dbones
    Hi. Sorry if this sounds like a newbie question, but the other day a Java developer mentioned about passing a paramter by reference (by which it was ment just pass a Reference object) From a C# perspective I can pass a reference type by value or by reference, this is also true to value types I have written a noddie console application to show what i mean.. can i do this in Java? namespace ByRefByVal { class Program { static void Main(string[] args) { //Creating of the object Person p1 = new Person(); p1.Name = "Dave"; PrintIfObjectIsNull(p1); //should not be null //A copy of the Reference is made and sent to the method PrintUserNameByValue(p1); PrintIfObjectIsNull(p1); //the actual reference is passed to the method PrintUserNameByRef(ref p1); //<-- I know im passing the Reference PrintIfObjectIsNull(p1); Console.ReadLine(); } private static void PrintIfObjectIsNull(Object o) { if (o == null) { Console.WriteLine("object is null"); } else { Console.WriteLine("object still references something"); } } /// <summary> /// this takes in a Reference type of Person, by value /// </summary> /// <param name="person"></param> private static void PrintUserNameByValue(Person person) { Console.WriteLine(person.Name); person = null; //<- this cannot affect the orginal reference, as it was passed in by value. } /// <summary> /// this takes in a Reference type of Person, by reference /// </summary> /// <param name="person"></param> private static void PrintUserNameByRef(ref Person person) { Console.WriteLine(person.Name); person = null; //this has access to the orginonal reference, allowing us to alter it, either make it point to a different object or to nothing. } } class Person { public string Name { get; set; } } } If it java cannot do this, then its just passing a reference type by value? (is that fair to say) Many thanks Bones

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  • Java Iterators - Trying to get a for each loop to work

    - by CS Student
    So I have a Tree<E> class where E is the datatype held and organized by the tree. I'd like to iterate through the Tree like this, or in a way similar to this: 1. Tree<String> tree=new Tree<String>(); 2. ...add some nodes... 3. for (String s : tree) 4. System.out.println(s); It gives me an error on line 3 though. Incompatible types required: java.lang.String found: java.lang.Object The following works fine and as expected though, performing a proper in-order traversal of the tree and printing each node out as it should: for (TreeIterator<String> i = tree.iterator(); i.hasNext(); ) System.out.println(i.next()); Any idea what I'm doing wrong? Do you need to see more of the code?

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  • How to do call function after client finishes download from tornado web server?

    - by Shabbyrobe
    I would like to be able to run some cleanup functions if and only if the client successfully completes the download of a file I'm serving using Tornado. I installed the firefox throttle tool and had it slow the connection down to dialup speed and installed this handler to generate a bunch of rubbish random text: class CrapHandler(BaseHandler): def get(self, token): crap = ''.join(random.choice(string.ascii_uppercase + string.digits) for x in range(100000)) self.write(crap) print "done" I get the following output from tornado immediately after making the request: done I 100524 19:45:45 web:772] 200 GET /123 (192.168.45.108) 195.10ms The client then plods along downloading for about 20 seconds. I expected that it would print "done" after the client was done. Also, if I do the following I get pretty much the same result: class CrapHandler(BaseHandler): @tornado.web.asynchronous def get(self, token): crap = ''.join(random.choice(string.ascii_uppercase + string.digits) for x in range(100000)) self.write(crap) self.finish() print "done" Am I missing something fundamental here? Can tornado even support what I'm trying to do? If not, is there an alternative that does?

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  • How do I use Google's Gson API to deserialize JSON properly?

    - by FK82
    Hi, In short, this is a sketch of the JSON object I want to parse in JAVA: { object1: { item1: //[String | Array | Object] , item2: // ... //<> more items object2: { // } //<> more objects } These are the POJO s I created for parsing (I'll leave out the import statements for brevity's sake): (1) The representation of the complete JSON object public class JObjectContainer { private List<JObject> jObjects ; public JObjectContainer() { // } //get & set methods } (2) The representation of the nested objects: public class JObject { private String id ; private List<JNode> jObjects ; public JObject() { // } //get & set methods } (3) The representation of the items: public class JNode { private JsonElement item1 ; private JsonElement item2 ; //<> more item fields public JNode() { // } //get & set methods } Now, creating a Gson instance (FileReader for importing the jsonFile), Gson gson = new Gson() ; JObjectContainer joc = gson(jsonFile,JObjectContainer.class) ; I get a NullPointerException whenever I try to access the parseable object (e.g. through a ListIterator). Gson does however create an object of the class I specified and does not throw any subsequent errors. I know that this has been done before. So, what am I missing? TIA

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  • Java library class to handle scheduled execution of "callbacks"?

    - by Hanno Fietz
    My program has a component - dubbed the Scheduler - that lets other components register points in time at which they want to be called back. This should work much like the Unix cron service, i. e. you tell the Scheduler "notify me at ten minutes past every full hour". I realize there are no real callbacks in Java. Here's my approach, is there a library which already does this stuff? Feel free to suggest improvements, too. Register call to Scheduler passes: a time specification containing hour, minute, second, year month, dom, dow, where each item may be unspecified, meaning "execute it every hour / minute etc." (just like crontabs) an object containing data that will tell the calling object what to do when it is notified by the Scheduler. The Scheduler does not process this data, just stores it and passes it back upon notification. a reference to the calling object Upon startup, or after a new registration request, the Scheduler starts with a Calendar object of the current system time and checks if there are any entries in the database that match this point in time. If there are, they are executed and the process starts over. If there aren't, the time in the Calendar object is incremented by one second and the entreis are rechecked. This repeats until there is one entry or more that match(es). (Discrete Event Simulation) The Scheduler will then remember that timestamp, sleep and wake every second to check if it is already there. If it happens to wake up and the time has already passed, it starts over, likewise if the time has come and the jobs have been executed. Edit: Thanks for pointing me to Quartz. I'm looking for something much smaller, however.

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  • java looping - declaration of a Class outside / inside the loop

    - by lisak
    when looping, for instance: for ( int j = 0; j < 1000; j++) {}; and I need to instantiate 1000 objects, how does it differ when I declare the object inside the loop from declaring it outside the loop ?? for ( int j = 0; j < 1000; j++) {Object obj; obj =} vs Object obj; for ( int j = 0; j < 1000; j++) {obj =} It's obvious that the object is accessible either only from the loop scope or from the scope that is surrounding it. But I don't understand the performance question, garbage collection etc. What is the best practice ? Thank you

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  • inserting selected page from one word document in another word document with c#

    - by daemonkid
    I have a requirement to move selected pages from word DocumentA into another word DocumentB. So in the end DocumentB should have its own contents plus selected pages from DocumentA inserted at selected pages in DocumentB. The page number in DocumentB I will set thru properties. This is the code I am using to just append contents of DocumentA to DocumentB. object missing = System.Reflection.Missing.Value; Word._Application wordApp = new Word.Application(); Word._Document aDoc = new Word.Document(); try { wordApp.Visible = false; object readOnly = false; object isVisible = false; aDoc = wordApp.Documents.Open(ref fPath1, ref missing, ref readOnly, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref isVisible, ref missing, ref missing, ref missing, ref missing); Word.Selection selection = wordApp.Selection; selection.InsertFile(fPath2, ref missing, ref missing, ref missing, ref missing); aDoc.Save(); wordApp.Quit(ref missing, ref missing, ref missing); } catch(Exception ex) { throw new Exception(ex.Message); } finally { wordApp = null; aDoc = null; } However, I keep getting this exception 'object reference not set to instance of object' at the line 'selection.InsertFile...' What is going wrong here? And how do I insert contents of page 2 from DocumentA into page 3 of DocumentB? Thanks for your time.

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  • CascadingDropDown ViewState Problem

    - by Steven
    I have two Ajax CascadingDropDown extenders on my page. After a postback, the value of the first dropdown is set (presumably) triggering an event for the second dropdown to refresh. Question: How do I maintain both the contents (from queries) and selected value of both dropdowns after postback? C# answers also welcome. Default.aspx Active States<br /><asp:DropDownList ID="StatesDrop" runat="server" /><br /> Active Cities<br /><asp:DropDownList ID="CitiesDrop" runat="server" /><br /> <ajax:CascadingDropDown ID="StatesCasc" TargetControlID="StatesDrop" ServicePath="WebService1.asmx" ServiceMethod="GetActiveStates" Category="States" runat="server" PromptText="Select a State" PromptValue="?" /> <ajax:CascadingDropDown ID="CitiesCasc" TargetControlID="CitiesDrop" ServicePath="WebService1.asmx" ServiceMethod="GetActiveCities" Category="Cities" runat="server" ParentControlID="StatesDrop" PromptText="Select a City" PromptValue="?" /> WebService1.asmx.vb Imports System.Web.Services Imports System.Web.Services.Protocols Imports System.ComponentModel Imports System.Web.Script.Services Imports AjaxControlToolkit <System.Web.Script.Services.ScriptService()> _ <System.Web.Services.WebService(Namespace:="http://tempuri.org/")> _ <System.Web.Services.WebServiceBinding _ (ConformsTo:=WsiProfiles.BasicProfile1_1)> _ <ToolboxItem(False)> _ Public Class WebService1: Inherits System.Web.Services.WebService <WebMethod()> _ Public Function GetActiveStates (ByVal knownCategoryValues As String, _ ByVal category As String) As CascadingDropDownNameValue() Dim values As New List(Of CascadingDropDownNameValue)() 'Populate values with query' Return values.ToArray() End Function <WebMethod()> _ Public Function GetActiveCities (ByVal knownCategoryValues As String, _ ByVal category As String) As CascadingDropDownNameValue() Dim kv As StringDictionary = _ CascadingDropDown.ParseKnownCategoryValuesString(knownCategoryValues) Dim SelState As String = "" If kv.ContainsKey("State") Then SelState = kv("State") Dim values As New List(Of CascadingDropDownNameValue)() ' Populate values with query.' Return values.ToArray() End Function End Class

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  • Setting generic type at runtime

    - by destroyer of evil
    I have a class public class A<T> { public static string B(T obj) { return TransformThisObjectToAString(obj); } } I can call the static function like this just fine on a known/specified type: string s= A<KnownType>.B(objectOfKnownType); How do I make this call, if I don't know T beforehand, rather I have a variable of type Type that holds the type. If I do this: Type t= typeof(string); string s= A<t>.B(someStringObject); I get this compiler error: Cannot implicitly convert type 't' to 'object'

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