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  • C# - WinForms - Exception Handling for Events

    - by JustLooking
    Hi all, I apologize if this is a simple question (my Google-Fu may be bad today). Imagine this WinForms application, that has this type of design: Main application - shows one dialog - that 1st dialog can show another dialog. Both of the dialogs have OK/Cancel buttons (data entry). I'm trying to figure out some type of global exception handling, along the lines of Application.ThreadException. What I mean is: Each of the dialogs will have a few event handlers. The 2nd dialog may have: private void ComboBox_SelectedIndexChanged(object sender, EventArgs e) { try { AllSelectedIndexChangedCodeInThisFunction(); } catch(Exception ex) { btnOK.enabled = false; // Bad things, let's not let them save // log stuff, and other good things } } Really, all the event handlers in this dialog should be handled in this way. It's an exceptional-case, so I just want to log all the pertinent information, show a message, and disable the okay button for that dialog. But, I want to avoid a try/catch in each event handler (if I could). A draw-back of all these try/catch's is this: private void someFunction() { // If an exception occurs in SelectedIndexChanged, // it doesn't propagate to this function combobox.selectedIndex = 3; } I don't believe that Application.ThreadException is a solution, because I don't want the exception to fall all the way-back to the 1st dialog and then the main app. I don't want to close the app down, I just want to log it, display a message, and let them cancel out of the dialog. They can decide what to do from there (maybe go somewhere else in the app). Basically, a "global handler" in between the 1st dialog and the 2nd (and then, I suppose, another "global handler" in between the main app and the 1st dialog). Thanks.

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  • How to eliminate Unhandled Exception dialog produced by 3rd party application

    - by Tappen
    I'm working with a 3rd party executable that I can't recompile (vendor is no longer available). It was originally written under .Net 1.1 but seems to work fine under later versions as well. I launch it using Process.Start from my own application (I've tried p/invoke CreateProcess as well with the same results so that's not relevant) Unfortunately this 3rd party app now throws an unhandled exception as it exits. The Microsoft dialog box has a title like "Exception thrown from v2.0 ... Broadcast Window" with the version number relating to the version of .Net it's running under (I can use a .exe.config file to target different .Net versions, doesn't help). The unhandled exception dialog box on exit doesn't cause any real problems, but is troubling to my users who have to click OK to dismiss it every time. Is there any way (a config file option perhaps) to disable this dialog from showing for an app I don't have the source code to? I've considered loading it in a new AppDomain which would give me access to the UnhandledException event but there's no indication I could change the appearence of the dialog. Maybe someone knows what causes the exception and I can fix this some other way?

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  • How to refactor use of the general Exception?

    - by Colin
    Our code catches the general exception everywhere. Usually it writes the error to a log table in the database and shows a MessageBox to the user to say that the operation requested failed. If there is database interaction, the transaction is rolled back. I have introduced a business logic layer and a data access layer to unravel some of the logic. In the data access layer, I have chosen not to catch anything and I also throw ArgumentNullExceptions and ArgumentOutOfRangeExceptions so that the message passed up the stack does not come straight from the database. In the business logic layer I put a try catch. In the catch I rollback the transaction, do the logging and rethrow. In the presentation layer there is another try catch that displays a MessageBox. I am now thinking about catching a DataException and an ArgumentException instead of an Exception where I know the code only accesses a database. Where the code accesses a web service, then I thought I would create my own "WebServiceException", which would be created in the data access layer whenever an HttpException, WebException or SoapException is thrown. So now, generally I will be catching 2 or 3 exceptions where currently I catch just the general Exception, and I think that seems OK to me. Does anyone wrap exceptions up again to carry the message up to the presentation layer? I think I should probably add a try catch to Main() that catches Exception, attempts to log it, displays an "Application has encountered an error" message and exits the application. So, my question is, does anyone see any holes in my plan? Are there any obvious exceptions that I should be catching or do these ones pretty much cover it (other than file access - I think there is only 1 place where we read-write to a config file).

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  • vb.net documentation and exception question

    - by dcp
    Let's say I have this sub in vb.net: ''' <summary> ''' Validates that <paramref name="value"/> is not <c>null</c>. ''' </summary> ''' ''' <param name="value">The object to validate.</param> ''' ''' <param name="name">The variable name of the object.</param> ''' ''' <exception cref="ArgumentNullException">If <paramref name="value"/> is <c>null</c>.</exception> Sub ValidateNotNull(ByVal value As Object, ByVal name As String) If value Is Nothing Then Throw New ArgumentNullException(name, String.Format("{0} cannot be null.", name)) End If End Sub My question is, is it proper to call this ValidateNotNull (which is what I would call it in C#) or should I stick with VB terminology and call it ValidateNotNothing instead? Also, in my exception, is it proper to say "cannot be null", or would it be better to say "cannot be Nothing"? I sort of like the way I have it, but since this is VB, maybe I should use Nothing. But since the exception itself is called ArgumentNullException, it feels weird to make the message say "cannot be Nothing". Anyway, I guess it's pretty nitkpicky, just wondered what you folks thought.

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  • Keep Hibernate Initializer from Crashing Program

    - by manyxcxi
    I have a Java program using a basic Hibernate session factory. I had an issue with a hibernate hbm.xml mapping file and it crashed my program even though I had the getSessionFactory() call in a try catch try { session = SessionFactoryUtil.getSessionFactory().openStatelessSession(); session.beginTransaction(); rh = getRunHistoryEntry(session); if(rh == null) { throw new Exception("No run history information found in the database for run id " + runId_ + "!"); } } catch(Exception ex) { logger.error("Error initializing hibernate"); } It still manages to break out of this try/catch and crash the main thread. How do I keep it from doing this? The main issue is I have a bunch of cleanup commands that NEED to be run before the main thread shuts down and need to be able to guarantee that even after a failure it still cleans up and goes down somewhat gracefully. The session factory looks like this: public class SessionFactoryUtil { private static final SessionFactory sessionFactory; static { try { // Create the SessionFactory from hibernate.cfg.xml sessionFactory = new Configuration().configure().buildSessionFactory(); } catch (Throwable ex) { // Make sure you log the exception, as it might be swallowed System.err.println("Initial SessionFactory creation failed." + ex); throw new ExceptionInInitializerError(ex); } } public static SessionFactory getSessionFactory() { try { return sessionFactory; } catch(Exception ex) { return null; } } }

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  • PHP: Exception not caught by try ... catch

    - by Christian Brenner
    I currently am working on an autoloader class for one of my projects. Below is the code for the controller library: public static function includeFileContainingClass($classname) { $classname_rectified = str_replace(__NAMESPACE__.'\\', '', $classname); $controller_path = ENVIRONMENT_DIRECTROY_CONTROLLERS.strtolower($classname_rectified).'.controller.php'; if (file_exists($controller_path)) { include $controller_path; return true; } else { // TODO: Implement gettext('MSG_FILE_CONTROLLER_NOTFOUND') throw new Exception('File '.strtolower($classname_rectified).'.controller.php not found.'); return false; } } And here's the code of the file I try to invoke the autoloader on: try { spl_autoload_register(__NAMESPACE__.'\\Controller::includeFileContainingClass'); } catch (Exception $malfunction) { die($malfunction->getMessage()); } // TESTING ONLY $test = new Testing(); When I try to force a malfunction, I get the following message: Fatal error: Uncaught exception 'Exception' with message 'File testing.controller.php not found.' in D:\cerophine-0.0.1-alpha1\application\libraries\controller.library.php:51 Stack trace: #0 [internal function]: application\Controller::includeFileContainingClass('application\Tes...') #1 D:\cerophine-0.0.1-alpha1\index.php(58): spl_autoload_call('application\Tes...') #2 {main} thrown in D:\cerophine-0.0.1-alpha1\application\libraries\controller.library.php on line 51 What seems to be wrong?

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  • Catch a thread's exception in the caller thread in Python

    - by Mikee
    Hi Everyone, I'm very new to Python and multithreaded programming in general. Basically, I have a script that will copy files to another location. I would like this to be placed in another thread so I can output "...." to indicate that the script is still running. The problem that I am having is that if the files cannot be copied it will throw an exception. This is ok if running in the main thread; however, having the following code does not work: try: threadClass = TheThread(param1, param2, etc.) threadClass.start() ##### **Exception takes place here** except: print "Caught an exception" In the thread class itself, I tried to re-throw the exception, but it does not work. I have seen people on here ask similar questions, but they all seem to be doing something more specific than what I am trying to do (and I don't quite understand the solutions offered). I have seen people mention the usage of sys.exc_info(), however I do not know where or how to use it. All help is greatly appreciated! EDIT: The code for the thread class is below: class TheThread(threading.Thread): def __init__(self, sourceFolder, destFolder): threading.Thread.__init__(self) self.sourceFolder = sourceFolder self.destFolder = destFolder def run(self): try: shul.copytree(self.sourceFolder, self.destFolder) except: raise

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  • java.lang.ExceptionInInitializerError Exception when creating Application Context in Spring

    - by cyotee
    I am practicing with Spring, and am getting a java.lang.ExceptionInInitializerError exception when I try to instantiate the context. The Exception appears below, with my code following it. I have simplified my experiment from before. The Exception Oct 17, 2012 5:54:22 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@570c16b7: startup date [Wed Oct 17 17:54:22 CDT 2012]; root of context hierarchy Exception in thread "main" java.lang.ExceptionInInitializerError at org.springframework.context.support.AbstractRefreshableApplicationContext.createBeanFactory(AbstractRefreshableApplicationContext.java:195) at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:128) at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:535) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:449) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83) at helloworld.HelloWorldTest.main(HelloWorldTest.java:13) Caused by: java.lang.NullPointerException at org.springframework.beans.factory.support.DefaultListableBeanFactory.<clinit>(DefaultListableBeanFactory.java:105) ... 7 more My configuration XML <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:c="http://www.springframework.org/schema/c" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd"> <bean id="messageContainer" class="helloworld.MessageContainer"> <property name="message" value="Hello World"> </property> </bean> <bean id="messageOutputService" class="helloworld.MessageOutputService"> </bean> My test class. package helloworld; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class HelloWorldTest { /** * @param args */ public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("HelloWorldTest-context.xml"); MessageContainer message = context.getBean(MessageContainer.class); MessageOutputService service = context.getBean(MessageOutputService.class); service.outputMessageToConsole(message); } }

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  • Java w/ SQL Server Express 2008 - Index out of range exception

    - by BS_C3
    Hi! I created a stored procedure in a sql express 2008 and I'm getting the following error when calling the procedure from a Java method: Index 36 is out of range. com.microsoft.sqlserver.jdbc.SQLServerException:Index 36 is out of range. at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:170) at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.setterGetParam(SQLServerPreparedStatement.java:698) at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.setValue(SQLServerPreparedStatement.java:707) at com.microsoft.sqlserver.jdbc.SQLServerCallableStatement.setString(SQLServerCallableStatement.java:1504) at fr.alti.ccm.middleware.Reporting.initReporting(Reporting.java:227) at fr.alti.ccm.middleware.Reporting.main(Reporting.java:396) I cannot figure out where it is coming from... _< Any help would be appreciated. Regards, BS_C3 Here's some source code: public ArrayList<ReportingTableMapping> initReporting( String division, String shop, String startDate, String endDate) { ArrayList<ReportingTableMapping> rTable = new ArrayList<ReportingTableMapping>(); ManagerDB db = new ManagerDB(); CallableStatement callStmt = null; ResultSet rs = null; try { callStmt = db.getConnexion().prepareCall("{call getInfoReporting(?,...,?)}"); callStmt.setString("CODE_DIVISION", division); . . . callStmt.setString("cancelled", " "); rs = callStmt.executeQuery(); while (rs.next()) { ReportingTableMapping rtm = new ReportingTableMapping( rs.getString("werks"), ... ); rTable.add(rtm); } rs.close(); callStmt.close(); } catch (Exception e) { System.out.println(e.getMessage()); e.printStackTrace(); } finally { if (rs != null) try { rs.close(); } catch (Exception e) { } if (callStmt != null) try { callStmt.close(); } catch (Exception e) { } if (db.getConnexion() != null) try { db.getConnexion().close(); } catch (Exception e) { } } return rTable; }

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  • php: autoload exception handling.

    - by YuriKolovsky
    Hello again, I'm extending my previous question (Handling exceptions within exception handle) to address my bad coding practice. I'm trying to delegate autoload errors to a exception handler. <?php function __autoload($class_name) { $file = $class_name.'.php'; try { if (file_exists($file)) { include $file; }else{ throw new loadException("File $file is missing"); } if(!class_exists($class_name,false)){ throw new loadException("Class $class_name missing in $file"); } }catch(loadException $e){ header("HTTP/1.0 500 Internal Server Error"); $e->loadErrorPage('500'); exit; } return true; } class loadException extends Exception { public function __toString() { return get_class($this) . " in {$this->file}({$this->line})".PHP_EOL ."'{$this->message}'".PHP_EOL . "{$this->getTraceAsString()}"; } public function loadErrorPage($code){ try { $page = new pageClass(); echo $page->showPage($code); }catch(Exception $e){ echo 'fatal error: ', $code; } } } $test = new testClass(); ?> the above script is supposed to load a 404 page if the testClass.php file is missing, and it works fine, UNLESS the pageClass.php file is missing as well, in which case I see a "Fatal error: Class 'pageClass' not found in D:\xampp\htdocs\Test\PHP\errorhandle\index.php on line 29" instead of the "fatal error: 500" message I do not want to add a try/catch block to each and every class autoload (object creation), so i tried this. What is the proper way of handling this?

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  • Is catching general exceptions really a bad thing?

    - by Bob Horn
    I typically agree with most code analysis warnings, and I try to adhere to them. However, I'm having a harder time with this one: CA1031: Do not catch general exception types I understand the rationale for this rule. But, in practice, if I want to take the same action regardless of the exception thrown, why would I handle each one specifically? Furthermore, if I handle specific exceptions, what if the code I'm calling changes to throw a new exception in the future? Now I have to change my code to handle that new exception. Whereas if I simply caught Exception my code doesn't have to change. For example, if Foo calls Bar, and Foo needs to stop processing regardless of the type of exception thrown by Bar, is there any advantage in being specific about the type of exception I'm catching?

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  • Exception Logging for WCF Services using ELMAH

    - by Ismail
    I tried this solution but I'm getting following exception System.ArgumentNullException was unhandled by user code Message="Value cannot be null.\r\nParameter name: context" Source="Elmah" ParamName="context" StackTrace: at Elmah.ErrorSignal.FromContext(HttpContext context) in c:\builds\ELMAH\src\Elmah\ErrorSignal.cs:line 67 at Elmah.ErrorSignal.FromCurrentContext() in c:\builds\ELMAH\src\Elmah\ErrorSignal.cs:line 61 at ElmahHttpErrorHandler.ProvideFault(Exception error, MessageVersion version, Message& fault) in c:\Myapplication\App_Code\Util\ElmahHttpErrorHandler.cs:line 19 at System.ServiceModel.Dispatcher.ErrorBehavior.ProvideFault(Exception e, FaultConverter faultConverter, ErrorHandlerFaultInfo& faultInfo) at System.ServiceModel.Dispatcher.ErrorBehavior.ProvideMessageFaultCore(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessageCleanup(MessageRpc& rpc) InnerException:

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  • How can I set up .NET UnhandledException handling in a Windows service?

    - by Mike Pateras
    protected override void OnStart(string[] args) { AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException); Thread.Sleep(10000); throw new Exception(); } void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e) { } I attached a debugger to the above code in my windows service, setting a breakpoint in CurrentDomain_UnhandledException, but it was never hit. The exception pops up saying that it is unhandled, and then the service stops. I even tried putting some code in the event handler, in case it was getting optimized away. Is this not the proper way to set up unhandled exception handling in a windows service?

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  • LINQ error when deployed - Security Exception - cannot create DataContext

    - by aximili
    The code below works locally, but when I deploy it to the server it gives the following error. Security Exception Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your system administrator or change the application's trust level in the configuration file. Exception Details: System.Security.SecurityException: Request for the permission of type 'System.Security.Permissions.FileIOPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed. The code is protected void Page_Load(object sender, EventArgs e) { DataContext context = new DataContext(Global.ConnectionString); // <-- throws the exception //Table<Group> _kindergartensTable = context.GetTable<Group>(); Response.Write("ok"); } I have set full write permissons on all files and folders on the server. Any suggestions how to solve this problem? Thanks in advance.

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  • C# File Exception: cannot access the file because it is being used by another process

    - by Lirik
    I'm trying to download a file from the web and save it locally, but I get an exception: C# The process cannot access the file 'blah' because it is being used by another process. This is my code: File.Create("data.csv"); // create the file request = (HttpWebRequest)WebRequest.CreateDefault(new Uri(url)); request.Timeout = 30000; response = (HttpWebResponse)request.GetResponse(); using (Stream file = File.OpenWrite("data.csv"), // <-- Exception here input = response.GetResponseStream()) { // Save the file using Jon Skeet's CopyStream method CopyStream(input, file); } I've seen numerous other questions with the same exception, but none of them seem to apply here. Any help?

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  • When to log exception?

    - by Rune
    try { // Code } catch (Exception ex) { Logger.Log("Message", ex); throw; } In the case of a library, should I even log the exception? Should I just throw it and allow the application to log it? My concern is that if I log the exception in the library, there will be many duplicates (because the library layer will log it, the application layer will log it, and anything in between), but if I don't log it in the library, it'll be hard to track down bugs. Is there a best practices for this?

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  • Tomcat Exception-Type Ignoring Specific Exception for More General

    - by David Marks
    For one type of exception, IOException, I want to display one page. For all other exceptions I have a default error page. In my web.xml I have things setup like this: java.io.IOException /queryException.jsp java.lang.Exception /error.jsp The problem is the error.jsp is the only page that ever shows, even if an IOException is thrown. The order the tags appear in doesn't matter; if I remove the java.lang.Exception tag though, I can get queryException to show for IOExceptions. What is the solution here? How can I keep a general error page for all exceptions EXCEPT for those with specific pages?

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  • Exception declared on ANTLR grammar rule ignored

    - by Kaleb Pederson
    I have a tree parser that's doing semantic analysis on the AST generated by my parser. It has a rule declared as follows: transitionDefinition throws WorkflowStateNotFoundException: /* ... */ This compiles just fine and matches the rule syntax at the ANTLR Wiki but my exception is never declared so the Java compiler complains about undeclared exceptions. ./tool/src/main/antlr3/org/antlr/grammar/v3/ANTLRv3.g shows that it's building a tree (but I'm not actually positive if it's the v2 or v3 grammar that ANTLR 3.2 is using): throwsSpec : 'throws' id ( ',' id )* -> ^('throws' id+) ; I know I can make it a runtime exception, but I'd like to use my exception hierarchy. Am I doing something wrong or should that syntax work?

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  • How to log python exception ?

    - by Maxim Veksler
    Hi, Coming from java, being familiar with logback I used to do try { ... catch (Exception e) { log("Error at X", e); } I would like the same functionality of being able to log the exception and the stacktrace into a file. How would you recommend me implementing this? Currently using boto logging infrastructre, boto.log.info(...) I've looked at some options and found out I can access the actual exception details using this code: import sys try: 1/0 except: exc_type, exc_value, exc_traceback = sys.exc_info() traceback.print_exception(exc_type, exc_value, exc_traceback) I would like to somehow get the string print_exception() throws to stdout so that I can log it. Thank you, Maxim.

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  • JNI_CreateJavaVM: Buffer overrun if I throw an exception in case of failure

    - by Dominik Fretz
    Hi, In a C++ project, I use the JNI invocation API to launch a JVM. I've done a little wrapper arount the JVM so I can use all the needed parts in a OO fashion. So far that works great. Now, if the JVM does not start (JNI_CreateJavaVM returns a value < 0) I'd like to raise an exception within my C++ code.But if I throw an exception after JNI_CreateJavaVM, I get a buffer overrun. If I raise the exception without the JNI_CreateJavaVM call, it works as expected. Does anyone have a clue on what the issue could be here? Or how to debug this? Environment: Windows, Visual Studio 2008 JDK: jrockit27.6jdk16005, but happens with SUN stock one as well Cheers Dominik

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  • Interface "not marked with serializable attribute" exception

    - by Joel in Gö
    I have a very odd exception in my C# app: when trying to deserialize a class containing a generic List<IListMember> (where list entries are specified by an interface), an exception is thrown reporting that "the type ...IListMember is not marked with the serializable attribute" (phrasing may be slightly different, my VisualStudio is not in English). Now, interfaces cannot be Serializable; the class actually contained in the list, implementing IListMember, is [Serializable]; and yes, I have checked that IListMember is in fact defined as an interface and not accidentally as a class! I have tried reproducing the exception in a separate test project only containing the class containing the List and the members, but there it serializes and deserializes happily :/ Does anyone have any good ideas about what it could be?

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  • How to stop .Net HttpWebRequest.GetResponse() raising an exception

    - by James
    Surely, surely, surely there is a way to configure the .Net HttpWebRequest object so that it does not raise an exception when HttpWebRequest.GetResponse() is called and any 300 or 400 status codes are returned? Jon Skeet does not think so, so I almost dare not even ask, but I find it hard to believe there is no way around this. 300 and 400 response codes are valid responses in certain circumstances. Why would we be always forced to incur the overhead of an exception? Perhaps there is some obscure configuration setting that evaded Jon Skeet? Perhaps there is a completely different type of request object that can be used that does not have this behavior? (and yes, I know you can just catch the exception and get the response from that, but I would like to find a way not to have to). Thanks for any help

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  • Need to determine if ELMAH is logging an unhandled exception or one raised by ErrorSignal.Raise()

    - by Ronnie Overby
    I am using the Elmah Logged event in my Global.asax file to transfer users to a feedback form when an unhandled exception occurs. Sometimes I log other handled exceptions. For example: ErrorSignal.FromCurrentContext().Raise(new System.ApplicationException("Program code not found: " + Student.MostRecentApplication.ProgramCode)); // more code that should execute after logging this exception The problem I am having is that the Logged event gets fired for both unhandled and these handled, raised exceptions. Is there a way to determine, in the Logged event handler, whether the exception was raised via ErrorSignal class or was simply unhandled? Are there other Elmah events that I can take advantage of?

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  • Condition checking vs. Exception handling

    - by Aidas Bendoraitis
    When is exception handling more preferable than condition checking? There are many situations where I can choose using one or the other. For example, this is a summing function which uses a custom exception: # module mylibrary class WrongSummand(Exception): pass def sum_(a, b): """ returns the sum of two summands of the same type """ if type(a) != type(b): raise WrongSummand("given arguments are not of the same type") return a + b # module application using mylibrary from mylibrary import sum_, WrongSummand try: print sum_("A", 5) except WrongSummand: print "wrong arguments" And this is the same function, which avoids using exceptions # module mylibrary def sum_(a, b): """ returns the sum of two summands if they are both of the same type """ if type(a) == type(b): return a + b # module application using mylibrary from mylibrary import sum_ c = sum_("A", 5) if c is not None: print c else: print "wrong arguments" I think that using conditions is always more readable and manageable. Or am I wrong? What are the proper cases for defining APIs which raise exceptions and why?

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  • ActiveRecord Create (not !) Throwing Exception on Validation

    - by myferalprofessor
    So I'm using ActiveRecord model validations to validate a form in a RESTful application. I have a create action that does: @association = Association.new and the receiving end of the form creates a data hash of attributes from the form parameters to save to the database using: @association = user.associations.create(data) I want to simply render the create action if validation fails. The problem is that the .create (not !) method is throwing an exception in cases where the model validation fails. Example: validates_format_of :url, :with => /(^$)|(^(http|https):\/\/[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(([0-9]{1,5})?\/.*)?$)/ix, :message => "Your url doesn't seem valid." in the model produces: ActiveRecord::RecordInvalid Exception: Validation failed: Url Your url doesn't seem valid. I thought .create! is supposed throw an exception whereas .create is not. Am I missing something here? Ruby 1.8.7 patchlevel 173 & rails 2.3.3

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