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  • Increasing time resolution of BOOST::progress timer

    - by feelfree
    BOOST::progress_timer is a very useful class to measure the running time of a function. However, the default implementation of progress_timer is not accurate enough and a possible way of increasing time resolution is to reconstruct a new class as the following codes show: #include <boost/progress.hpp> #include <boost/static_assert.hpp> template<int N=2> class new_progress_timer:public boost::timer { public: new_progress_timer(std::ostream &os=std::cout):m_os(os) { BOOST_STATIC_ASSERT(N>=0 &&N<=10); } ~new_progress_timer(void) { try { std::istream::fmtflags old_flags = m_os.setf(std::istream::fixed,std::istream::floatfield); std::streamsize old_prec = m_os.precision(N); m_os<<elapsed()<<"s\n" <<std::endl; m_os.flags(old_flags); m_os.precison(old_prec); } catch(...) { } } private: std::ostream &m_os; }; However, when I compile the codes with VC10, the following error appear: 'precison' : is not a member of 'std::basic_ostream<_Elem,_Traits>' Any ideas? Thanks.

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  • Identity.Name is disposed in a IIS7 Asp.NET MVC application Thread

    - by vIceBerg
    I have made the smallest demo project to illustrate my problem. You can download the sources Here Visual Studio 2008, .NET 3.5, IIS7, Windows 7 Ultimate 32 bits. The IIS Website is configured ONLY for Windows Authentication in an Integreated pipeline app pool (DefaultAppPool). Here's the problem. I have an Asp.NET MVC 2 application. In an action, I start a thread. The View returns. The thread is doing it's job... but it needs to access Thread.CurrentPrincipal.Identity.Name BANG The worker process of IIS7 stops. I have a window that says: "Visual Studio Just-In-Time Debugger An unhandled exception ('System.Object.DisposedException') occured in w3wp.exe [5524]" I checked with the debugger and the Thread.CurrentPrincipal.Identity is valid, but the Name property is disposed. If I put a long wait in the action before it returns the view, then the Thread can do it's job and the Identity.Name is not disposed. So I think the Name gets disposed when the view is returned. For the sake of the discussion, here's the code that the thread runs (but you can also download the demo project. The link is on top of this post): private void Run() { const int SECTOWAIT = 3; //wait SECTOWAIT seconds long end = DateTime.Now.Ticks + (TimeSpan.TicksPerSecond * SECTOWAIT); while (DateTime.Now.Ticks <= end) continue; //Check the currentprincipal. BANG!!!!!!!!!!!!! var userName = Thread.CurrentPrincipal.Identity.Name; } Here's the code that starts the thread public void Start() { Thread thread = new Thread(new ParameterizedThreadStart(ThreadProc)); thread.SetApartmentState(ApartmentState.MTA); thread.Name = "TestThread"; thread.Start(this); } static void ThreadProc(object o) { try { Builder builder = (Builder)o; builder.Run(); } catch (Exception ex) { throw; } } So... what am i doing wrong? Thanks

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  • What's the best way to only output a tag if it exists in XSL?

    - by Morinar
    I'm working on an interface with a 3rd party app that basically needs to take XML that was spat out by the app and convert it into XML our system can deal with. It's basically just applying a stylesheet to the original XML to make it looks like "our" XML. I've noticed that in other stylesheets we have, there are constructs like this: <xsl:for-each select="State"> <StateAbbreviation> <xsl:value-of select="."/> </StateAbbreviation> </xsl:for-each> Basically, the "in" XML has a State tag that I need to output as our recognized StateAbbreviation tag. However, I want to ONLY output the StateAbbreviation tag if the "in" XML contains the State tag. The block above accomplishes this just fine, but is not very intuitive (at least it wasn't to me), as every time I see a for-each I assume there is more than one, whereas in these cases there is 0 or 1. My question: is that a standard-ish construct? If not, is there a more preferred way to do it? I could obviously check the string length (which is also being done in other stylesheets), but would like to do it the same, "best" way everywhere (assuming of course that a "best" way exists. Advice? Suggestions?

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  • many to many and integrity when saving the null

    - by user369759
    I have two classes Software, Tag - they are related by ManyToMany. We CAN NOT create Software without putting the Tag to it. I want to write a test which check that: @Test public void createSoftwareWithNullTags() { List<Tag> tags = null; Software software = new Software("software1", "description1", tags); try { software.save(); fail("tags should not be null"); } catch (Exception ex) { // NEVER COME HERE !!! } } So, this test fails. I guess it is not good test for that case - because it even do not try to SAVE data to SOFTWARE_TAG table. Of course i could do validation manually but i want implement it with hibernate, using some annotation or something. Is it possible? Or how would you do this? My entities: @Entity public class Tag extends Model { public String title; public Tag(String title) { this.title = title; } @ManyToMany( cascade = {CascadeType.ALL}, mappedBy = "tags", targetEntity = Software.class ) public List<Software> softwares; } @Entity public class Software extends Model { public String title; public String description; @ManyToOne(optional = false) public Author author; @ManyToMany(cascade = CascadeType.ALL) @JoinTable( name = "SOFTWARE_TAG", joinColumns = @JoinColumn(name = "Software_id"), inverseJoinColumns = @JoinColumn(name = "Tag_id") ) public List<Tag> tags; public Software(String title, String description, Author author, List<Tag> tags) { this.title = title; this.description = description; this.author = author; this.tags = tags; } }

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  • Load PEM encoded private RSA key in Crypto++

    - by 01100110
    Often times, user will have PEM encoded RSA private keys. Crypto++ requires that these keys be in DER format to load. I've been asking people to manually convert their PEM files to DER beforehand using openssl like this: openssl pkcs8 -in in_file.pem -out out_file.der -topk8 -nocrypt -outform der That works fine, but some people don't understand how to do that nor do they want to. So I would like to convert PEM files to DER files automatically within the program. Is it as simple as striping the "-----BEGIN CERTIFICATE-----" and "-----END CERTIFICATE-----" from the PEM or is some other transformation required as well? I've been told that between those markers that it's just b64 encoded DER. Here's some code that demonstrates the issue: // load the private key CryptoPP::RSA::PrivateKey PK; CryptoPP::ByteQueue bytes; try { CryptoPP::FileSource File( rsa.c_str(), true, new CryptoPP::Base64Decoder() ); File.TransferTo( bytes ); bytes.MessageEnd(); // This line Causes BERDecodeError when a PEM encoded file is used PK.Load( bytes ); } catch ( CryptoPP::BERDecodeErr ) { // Convert PEM to DER and try to load the key again } I'd like to avoid making system calls to openssl and do the transformation entirely in Crypto++ so that users can provide either format and things "just work". Thanks for any advice.

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  • Scale an image which is stored as a byte[] in Java

    - by Sergio del Amo
    I upload a file with a struts form. I have the image as a byte[] and I would like to scale it. FormFile file = (FormFile) dynaform.get("file"); byte[] fileData = file.getFileData(); fileData = scale(fileData,200,200); public byte[] scale(byte[] fileData, int width, int height) { // TODO } Anyone knows an easy function to do this? public byte[] scale(byte[] fileData, int width, int height) { ByteArrayInputStream in = new ByteArrayInputStream(fileData); try { BufferedImage img = ImageIO.read(in); if(height == 0) { height = (width * img.getHeight())/ img.getWidth(); } if(width == 0) { width = (height * img.getWidth())/ img.getHeight(); } Image scaledImage = img.getScaledInstance(width, height, Image.SCALE_SMOOTH); BufferedImage imageBuff = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); imageBuff.getGraphics().drawImage(scaledImage, 0, 0, new Color(0,0,0), null); ByteArrayOutputStream buffer = new ByteArrayOutputStream(); ImageIO.write(imageBuff, "jpg", buffer); return buffer.toByteArray(); } catch (IOException e) { throw new ApplicationException("IOException in scale"); } } If you run out of Java Heap Space in tomcat as I did, increase the heap space which is used by tomcat. In case you use the tomcat plugin for Eclipse, next should apply: In Eclipse, choose Window Preferences Tomcat JVM Settings Add the following to the JVM Parameters section -Xms256m -Xmx512m

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  • Integer array or struct array - which is better?

    - by MusiGenesis
    In my app, I'm storing Bitmap data in a two-dimensional integer array (int[,]). To access the R, G and B values I use something like this: // read: int i = _data[x, y]; byte B = (byte)(i >> 0); byte G = (byte)(i >> 8); byte R = (byte)(i >> 16); // write: _data[x, y] = BitConverter.ToInt32(new byte[] { B, G, R, 0 }, 0); I'm using integer arrays instead of an actual System.Drawing.Bitmap because my app runs on Windows Mobile devices where the memory available for creating bitmaps is severely limited. I'm wondering, though, if it would make more sense to declare a structure like this: public struct RGB { public byte R; public byte G; public byte B; } ... and then use an array of RGB instead of an array of int. This way I could easily read and write the separate R, G and B values without having to do bit-shifting and BitConverter-ing. I vaguely remember something from days of yore about byte variables being block-aligned on 32-bit systems, so that a byte actually takes up 4 bytes of memory instead of just 1 (but maybe this was just a Visual Basic thing). Would using an array of structs (like the RGB example` above) be faster than using an array of ints, and would it use 3/4 the memory or 3 times the memory of ints?

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  • Does C# allow method overloading, PHP style (__call)?

    - by mr.b
    In PHP, there is a special method named __call($calledMethodName, $arguments), which allows class to catch calls to non-existing methods, and do something about it. Since most of classic languages are strongly typed, compiler won't allow calling a method that does not exist, I'm clear with that part. What I want to accomplish (and I figured this is how I would do it in PHP, but C# is something else) is to proxy calls to a class methods and log each of these calls. Right now, I have code similar to this: class ProxyClass { static logger; public AnotherClass inner { get; private set; } public ProxyClass() { inner = new AnotherClass(); } } class AnotherClass { public void A() {} public void B() {} public void C() {} // ... } // meanwhile, in happyCodeLandia... ProxyClass pc = new ProxyClass(); pc.inner.A(); pc.inner.B(); // ... So, how can I proxy calls to an object instance in extensible way? Extensible, meaning that I don't have to modify ProxyClass whenever AnotherClass changes. In my case, AnotherClass can have any number of methods, so it wouldn't be appropriate to overload or wrap all methods to add logging. I am aware that this might not be the best approach for this kind of problem, so if anyone has idea what approach to use, shoot. Thanks!

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  • CSS- How to align background image over bottom border line? Jsfiddle included

    - by John Robinson
    I have an image I am trying to display over the top of a bottom border, but it is being arranged behind the bottom border element (in this example, named "divider"), and I can't get it to align correctly. I would like the image to be displayed in the middle of the the border element and over the top of it. Vertically, I am trying to get the 1px line on the left and right side of the image to align with the 1px border to appear as if it is one element. Here is the code: .divider { border-bottom: 1px solid #c3c3c3; clear: both; display: block; margin-bottom: 20px; padding-top: 20px; width: 100%; } .sidearrow { background: url(http://s16.postimage.org/sbf7v9n75/sidearrow.png) 50% 14px no-repeat; width: 100%; height: 25px; }? <p>Here is some content above</p> <div class="sidearrow"></div> <div class="divider"></div> <p>Here is some content below</p>? And the jsfiddle: http://jsfiddle.net/F5xjx/2/ Any ideas how to get this to work? Thanks in advance.

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  • joomla and allow_url_fopen [closed]

    - by liz
    so i have been reading of the pros and cons of allowing: allow_url_fopen. but i am still confused. after a recent hacking incident (which i believe had nothing to do with allow_url_fopen) my host turned allow_url_fopen off. so the thing i dont get is, in joomla 2.5.x there is an updating feature.you can search for new versions and be notified if things are out of date. there is a big security hole if joomla or its extensions get out of date. But the catch it needs allow_url_fopen turned on. so why did joomla build a security risk into a feature to improve security??is it okay to turn allow_url_fopen on and have the updating feature? to clarify: my question is. i have Joomla installed. I have CURl installed. when i run the discover updates through NATIVE joomla i get a request for fopen. shouldn't i not need to enable a security risk? i am running version 2.5.8 of joomla.

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  • Five unique, random numbers from a subset

    - by tau
    I know similar questions come up a lot and there's probably no definitive answer, but I want to generate five unique random numbers from a subset of numbers that is potentially infinite (maybe 0-20, or 0-1,000,000). The only catch is that I don't want to have to run while loops or fill an array. My current method is to simply generate five random numbers from a subset minus the last five numbers. If any of the numbers match each other, then they go to their respective place at the end of the subset. So if the fourth number matches any other number, it will bet set to the 4th from the last number. Does anyone have a method that is "random enough" and doesn't involve costly loops or arrays? Please keep in mind this a curiosity, not some mission-critical problem. I would appreciate it if everyone didn't post "why are you having this problem?" answers. I am just looking for ideas. Thanks a lot!

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  • How do I connect to SQL Server with VB?

    - by Wayne Werner
    Hi, I'm trying to connect to a SQL server from VB. The SQL server is across the network uses my windows login for authentication. I can access the server using the following python code: import odbc conn = odbc.odbc('SignInspection') c = conn.cursor() c.execute("SELECT * FROM list_domain") c.fetchone() This code works fine, returning the first result of the SELECT. However, I've been trying to use the SqlClient.SqlConnection in VB, and it fails to connect. I've tried several different connection strings but this is the current code: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim conn As New SqlClient.SqlConnection conn.ConnectionString = "data source=signinspection;initial catalog=signinspection;integrated security=SSPI" Try conn.Open() MessageBox.Show("Sweet Success") 'Insert some code here, woo Catch ex As Exception MessageBox.Show("Failed to connect to data source.") MessageBox.Show(ex.ToString()) Finally conn.Close() End Try End Sub It fails miserably, and it gives me an error that says "A network-related or instance-specific error occurred... (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) I'm fairly certain it's my connection string, but nothing I've found has given me any solid examples (server=mySQLServer is not a solid example) of what I need to use. Thanks! -Wayne

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  • How to insert array into mysql using PDO and bindParam?

    - by moomoochoo
    I'm using the following code. The code works, but I want to change it so that it uses bindparam try { $dbh = new PDO("mysql:host=$hostname;dbname=$dbname", $username, $password); $stqid=array(); for ($i=0; $i<$array_count; $i++){ $stqid[$i][0]=$lastInsertValue; $stqid[$i][1]=$qid[$i][0]; $stqid[$i][2]=$qid[$i][1]; } $values = array(); foreach ($stqid as $rowValues) { foreach ($rowValues as $key => $rowValue) { $rowValues[$key] = $rowValues[$key]; } $values[] = "(" . implode(', ', $rowValues) . ")"; } $count = $dbh->exec("INSERT INTO qresults(instance, qid, result) VALUES ".implode (', ', $values)); $dbh = null; } catch(PDOException $e){ echo $e->getMessage(); } I replaced the following $count = $dbh->exec("INSERT INTO qresults(instance, qid, result) VALUES ".implode (', ', $values)); with $sql = "INSERT INTO qresults (instance, qid, result) VALUES (:an_array)"; $stmt = $dbh->prepare($sql); $stmt->bindParam(':an_array', implode(',', $values),PDO::PARAM_STR); $stmt->execute(); but the insert doesn't work anymore (I didn't get any error messages though). QUESTION: What am I doing wrong? How can I rewrite the code to use bindParam?

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  • ASP.NET MVC Unit Testing Controllers - Repositories

    - by Brian McCord
    This is more of an opinion seeking question, so there may not be a "right" answer, but I would welcome arguments as to why your answer is the "right" one. Given an MVC application that is using Entity Framework for the persistence engine, a repository layer, a service layer that basically defers to the repository, and a delete method on a controller that looks like this: public ActionResult Delete(State model) { try { if( model == null ) { return View( model ); } _stateService.Delete( model ); return RedirectToAction("Index"); } catch { return View( model ); } } I am looking for the proper way to Unit Test this. Currently, I have a fake repository that gets used in the service, and my unit test looks like this: [TestMethod] public void Delete_Post_Passes_With_State_4() { //Arrange var stateService = GetService(); var stateController = new StateController( stateService ); ViewResult result = stateController.Delete( 4 ) as ViewResult; var model = (State)result.ViewData.Model; //Act RedirectToRouteResult redirectResult = stateController.Delete( model ) as RedirectToRouteResult; stateController = new StateController( stateService ); var newresult = stateController.Delete( 4 ) as ViewResult; var newmodel = (State)newresult.ViewData.Model; //Assert Assert.AreEqual( redirectResult.RouteValues["action"], "Index" ); Assert.IsNull( newmodel ); } Is this overkill? Do I need to check to see if the record actually got deleted (as I already have Service and Repository tests that verify this)? Should I even use a fake repository here or would it make more sense just to mock the whole thing? The examples I'm looking at used this model of doing things, and I just copied it, but I'm really open to doing things in a "best practices" way. Thanks.

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  • How to check for a null object reference when validating forms in MVC

    - by quakkels
    Hello SO, I'm experimenting with validating forms in the asp.net MVC framework. I'm focusing on server side validation for the time being. I've come across an error that I'm not sure how to rectify. System.NullReferenceException: Object reference not set to an instance of an object. The code that throws the error is: [AcceptVerbs(HttpVerbs.Post)] public ActionResult Create([Bind(Exclude="ID")] MembersCreate mc ) { mc.Modules = ModuleListDataContext.GetModuleList(); ViewData.Model = mc; //Validation using ModelState // // //line below errors when form field is empty // if ((string)mc.Member.Username.Trim() == "") ModelState.AddModelError("Member.Username", "Username is required."); if (!ModelState.IsValid) return View(); try { // TODO: Add insert logic here return RedirectToAction("Index","Home"); } catch { return View(); } } When I put spaces in the field it performs exactly as i want, but if I leave the field blank and press submit I get the error. What's the best way to avoid this error and still validate blank form fields? Thanks all -

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  • How To Deal With Exceptions In Large Code Bases

    - by peter
    Hi All, I have a large C# code base. It seems quite buggy at times, and I was wondering if there is a quick way to improve finding and diagnosing issues that are occuring on client PCs. The most pressing issue is that exceptions occur in the software, are caught, and even reported through to me. The problem is that by the time they are caught the original cause of the exception is lost. I.e. If an exception was caught in a specific method, but that method calls 20 other methods, and those methods each call 20 other methods. You get the picture, a null reference exception is impossible to figure out, especially if it occured on a client machine. I have currently found some places where I think errors are more likely to occur and wrapped these directly in their own try catch blocks. Is that the only solution? I could be here a long time. I don't care that the exception will bring down the current process (it is just a thread anyway - not the main application), but I care that the exceptions come back and don't help with troubleshooting. Any ideas? I am well aware that I am probably asking a question which sounds silly, and may not have a straightforward answer. All the same some discussion would be good.

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  • PHP -- automatic SQL injection protection?

    - by ashgromnies
    I took over maintenance of a PHP app recently and I'm not super familiar with PHP but some of the things I've been seeing on the site are making me nervous that it could be vulnerable to a SQL injection attack. For example, see how this code for logging into the administrative section works: $password = md5(HASH_SALT . $_POST['loginPass']); $query = "SELECT * FROM `administrators` WHERE `active`='1' AND `email`='{$_POST['loginEmail']}' AND `password`='{$password}'"; $userInfo = db_fetch_array(db_query($query)); if($userInfo['id']) { $_SESSION['adminLoggedIn'] = true; // user is logged in, other junk happens here, not important The creators of the site made a special db_query method and db_fetch_array method, shown here: function db_query($qstring,$print=0) { return @mysql(DB_NAME,$qstring); } function db_fetch_array($qhandle) { return @mysql_fetch_array($qhandle); } Now, this makes me think I should be able to do some sort of SQL injection attack with an email address like: ' OR 'x'='x' LIMIT 1; and some random password. When I use that on the command line, I get an administrative user back, but when I try it in the application, I get an invalid username/password error, like I should. Could there be some sort of global PHP configuration they have enabled to block these attacks? Where would that be configured? Here is the PHP --version information: # php --version PHP 5.2.12 (cli) (built: Feb 28 2010 15:59:21) Copyright (c) 1997-2009 The PHP Group Zend Engine v2.2.0, Copyright (c) 1998-2009 Zend Technologies with the ionCube PHP Loader v3.3.14, Copyright (c) 2002-2010, by ionCube Ltd., and with Zend Optimizer v3.3.9, Copyright (c) 1998-2009, by Zend Technologies

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  • Dynamic Auto updating (to UI, Grid) binding list in C# Winform?

    - by Dhana
    I'm not even sure if i'm doing this correctly. But basically I have a list of objects that are built out of a class/interface. From there, I am binding the list to a datagrid view that is on a Windows Form (C#) Here the list is a Sync list which will auto update the UI, in this case datagridview. Every thing works fine now, but now i would like to have the List should have an dynamic object, that is the object will have by default two static property (ID, Name), and at run time user will select remaining properties. These should be bind to the data grid. Any update on the list should be auto reflected in the grid. I am aware that, we can use dynamic objects, but i would like to know , how to approach for solution, datagridview.DataSource = myData; // myData is AutoUpdateList<IPersonInfo> Now IPersonInfo is the type of object, need to add dynamic properties for this type at runtime. public class AutoUpdateList<T> : System.ComponentModel.BindingList<T> { private System.ComponentModel.ISynchronizeInvoke _SyncObject; private System.Action<System.ComponentModel.ListChangedEventArgs> _FireEventAction; public AutoUpdateList() : this(null) { } public AutoUpdateList(System.ComponentModel.ISynchronizeInvoke syncObject) { _SyncObject = syncObject; _FireEventAction = FireEvent; } protected override void OnListChanged(System.ComponentModel.ListChangedEventArgs args) { try { if (_SyncObject == null) { FireEvent(args); } else { _SyncObject.Invoke(_FireEventAction, new object[] { args }); } } catch (Exception) { // TODO: Log Here } } private void FireEvent(System.ComponentModel.ListChangedEventArgs args) { base.OnListChanged(args); } } Could you help out on this?

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  • File streaming in PHP - How to replicate this C#.net code in PHP?

    - by openid_kenja
    I'm writing an interface to a web service where we need to upload configuration files. The documentation only provides a sample in C#.net which I am not familiar with. I'm trying to implement this in PHP. Can someone familiar with both languages point me in the right direction? I can figure out all the basics, but I'm trying to figure out suitable PHP replacements for the FileStream, ReadBytes, and UploadDataFile functions. I believe that the RecService object contains the URL for the web service. Thanks for your help! private void UploadFiles() { clientAlias = “<yourClientAlias>”; string filePath = “<pathToYourDataFiles>”; string[] fileList = {"Config.txt", "ProductDetails.txt", "BrandNames.txt", "CategoryNames.txt", "ProductsSoldOut.txt", "Sales.txt"}; RecommendClient RecService = new RecommendClient(); for (int i = 0; i < fileList.Length; i++) { bool lastFile = (i == fileList.Length - 1); //start generator after last file try { string fileName = filePath + fileList[i]; if (!File.Exists(fileName)) continue; // file not found } // set up a file stream and binary reader for the selected file and convert to byte array FileStream fStream = new FileStream(fileName, FileMode.Open, FileAccess.Read); BinaryReader br = new BinaryReader(fStream); byte[] data = br.ReadBytes((int)numBytes); br.Close(); // pass byte array to the web service string result = RecService.UploadDataFile(clientAlias, fileList[i], data, lastFile); fStream.Close(); fStream.Dispose(); } catch (Exception ex) { // log an error message } } }

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  • rails delete_all exception

    - by Sergei
    Hello, guys! I have some User model, Role model and Assignment model to manage role-based user system. Just like here . So, here some kind of code, to include roles into users form: <% for role in Role.all %> <%= check_box_tag "user[role_ids][]", role.id, @user.roles.include?(role) %> <%=h role.name %><br /> <% end %> And all's working fine for new records and for editing records. But I just want to make possible to restrict deleting Assigment with id=1, cause this Assignment for default root user from migration, who must be admin anyway. Otherwise, I can lose my last admin. So I've tryed to add before_destroy to Assignment.rb model, but it doesn't work. I've noticed, that when I'm editing user and trying to remove his admin role(assignment), the server makes a delete_all method, not destroy method. So, does anybody know how to catch the deleting of Assignment with id=1 through this kind of code? Thanks in advance!

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  • Sequential access to asynchronous sockets

    - by Lars A. Brekken
    I have a server that has several clients C1...Cn to each of which there is a TCP connection established. There are less than 10,000 clients. The message protocol is request/response based, where the server sends a request to a client and then the client sends a response. The server has several threads, T1...Tm, and each of these may send requests to any of the clients. I want to make sure that only one of these threads can send a request to a specific client at any one time, while the other threads wanting to send a request to the same client will have to wait. I do not want to block threads from sending requests to different clients at the same time. E.g. If T1 is sending a request to C3, another thread T2 should not be able to send anything to C3 until T1 has received its response. I was thinking of using a simple lock statement on the socket: lock (c3Socket) { // Send request to C3 // Get response from C3 } I am using asynchronous sockets, so I may have to use Monitor instead: Monitor.Enter(c3Socket); // Before calling .BeginReceive() And Monitor.Exit(c3Socket); // In .EndReceive I am worried about stuff going wrong and not letting go of the monitor and therefore blocking all access to a client. I'm thinking that my heartbeat thread could use Monitor.TryEnter() with a timeout and throw out sockets that it cannot get the monitor for. Would it make sense for me to make the Begin and End calls synchronous in order to be able to use the lock() statement? I know that I would be sacrificing concurrency for simplicity in this case, but it may be worth it. Am I overlooking anything here? Any input appreciated.

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  • Pass scalar/list context to called subroutine

    - by Will
    I'm trying to write a sub that takes a coderef parameter. My sub does some initialization, calls the coderef, then does some cleanup. I need to call the coderef using the same context (scalar, list, void context) that my sub was called in. The only way I can think of is something like this: sub perform { my ($self, $code) = @_; # do some initialization... my @ret; my $ret; if (not defined wantarray) { $code->(); } elsif (wantarray) { @ret = $code->(); } else { $ret = $code->(); } # do some cleanup... if (not defined wantarray) { return; } elsif (wantarray) { return @ret; } else { return $ret; } } Obviously there's a good deal of redundancy in this code. Is there any way to reduce or eliminate any of this redundancy? EDIT   I later realized that I need to run $code->() in an eval block so that the cleanup runs even if the code dies. Adding eval support, and combining the suggestions of user502515 and cjm, here's what I've come up with. sub perform { my ($self, $code) = @_; # do some initialization... my $w = wantarray; return sub { my $error = $@; # do some cleanup... die $error if $error; # propagate exception return $w ? @_ : $_[0]; }->(eval { $w ? $code->() : scalar($code->()) }); } This gets rid of the redundancy, though unfortunately now the control flow is a little harder to follow.

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  • how to use a list containing the query result with hibernate and display it in jsp

    - by kawtousse
    hi everyone, In my servlet I construct the query like the following: net.sf.hibernate.Session s = null; net.sf.hibernate.Transaction tx; try { s= HibernateUtil.currentSession(); tx=s.beginTransaction(); Query query = s.createQuery("select opcemployees.Nom,opcemployees.Prenom,dailytimesheet.TrackingDate,dailytimesheet.Activity," + "dailytimesheet.ProjectCode,dailytimesheet.WAName,dailytimesheet.TaskCode," + "dailytimesheet.TimeSpent,dailytimesheet.PercentTaskComplete from Opcemployees opcemployees,Dailytimesheet dailytimesheet " + "where opcemployees.Matricule=dailytimesheet.Matricule and dailytimesheet.Etat=3 " + "group by opcemployees.Nom,opcemployees.Prenom" ); List opdts= query.list(); request.setAttribute("items", opdts); request.getRequestDispatcher("EspaceValidation.jsp").forward(request, response); } catch (HibernateException e){ e.printStackTrace();} But in the jsp I can't display the result correctly. I do the following in JSP: <table> <c:forEach items="${items}" var="item"> <tr> <td>${item}</td> </tr> </c:forEach> </table> thanks for help.

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  • Problems with LWUIT in J2ME on Nokia E72

    - by Andre Mariano
    Well, I'm developing a app in my cellphone that is going to connect to my PC, the problem is that everytime that I return a URLRequest to the cellphone, it shows the previous Form on the screen and not de actual one, for example this is what goes in my actionListener: public void actionPerformed(ActionEvent ae) { if (ae.getCommand() == guiaUtil.cSelecionar()) { LoginRemote loginRemote = new LoginRemote(); try { //This is the request, returns true or false, does not affect the form loginRemote.login(tLogin.getText(), tPassword.getText()); } catch (Exception e) { GuiaUtil.error(e); return; } guiaUtil.mainApp().startMenu(); } } Then in the "guiaUtil.mainApp().startMenu()" I have this public void startMenu() { if (itemsMenu == null) { itemsMenu = new List(); itemsMenu.setWidth(320); itemsMenu.addItem("Sincronize Spots"); itemsMenu.addItem("Find Spots"); itemsMenu.addItem("Work"); itemsMenu.setFocus(true); this.addComponent(itemsMenu); this.addCommandListener(this); this.addCommand(guiaUtil.cSelect()); Form form = new Form(); form.addComponent(itemsMenu); } form.show(); } Anyway, after the request returns, it shows my Login form again, instead of showing the Menu List

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  • Getting Outlook calendar items based on subject

    - by EKS
    I'm trying to get a list of calendar objects from exchange and sorting them based on subject. The part of of getting the objects just based on date and sorting out via subject is in "code" is now working, but i want to do a sort on subject in the "sql" first, but im unable to make it work ( Currently getting error from exchange saying the query is wrong. The line I added is: + "AND lcase(\"urn:schemas:calendar:subject\") = 'onsite%' " What I want is the ability to catch all appointments that start with onsite, both in upper and lower case. strQuery = "<?xml version=\"1.0\"?>" + "<g:searchrequest xmlns:g=\"DAV:\">" + "<g:sql>SELECT \"urn:schemas:calendar:location\", \"urn:schemas:httpmail:subject\", " + "\"urn:schemas:calendar:dtstart\", \"urn:schemas:calendar:dtend\", " + "\"urn:schemas:calendar:busystatus\", \"urn:schemas:calendar:instancetype\" " + "FROM Scope('SHALLOW TRAVERSAL OF \"" + strCalendarURI + "\"') " + "WHERE NOT \"urn:schemas:calendar:instancetype\" = 1 " + "AND \"DAV:contentclass\" = 'urn:content-classes:appointment' " + "AND \"urn:schemas:calendar:dtstart\" > '2003/06/01 00:00:00' " //'" + DateString + "'" + "AND lcase(\"urn:schemas:calendar:subject\") = 'onsite' " + "ORDER BY \"urn:schemas:calendar:dtstart\" ASC" + "</g:sql></g:searchrequest>";

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