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  • Java: ResultSet exception - before start of result set

    - by Rosarch
    I'm having trouble getting data from a ResultSet object. Here is my code: String sql = "SELECT type FROM node WHERE nid = ?"; PreparedStatement prep = conn.prepareStatement(sql); int meetNID = Integer.parseInt(node.get(BoutField.field_meet_nid)); prep.setInt(1, meetNID); ResultSet result = prep.executeQuery(); result.beforeFirst(); String foundType = result.getString(1); if (! foundType.equals("meet")) { throw new IllegalArgumentException(String.format("Node %d must be of type 'meet', but was %s", meetNID, foundType)); } The error trace: Exception in thread "main" java.sql.SQLException: Before start of result set at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1072) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:986) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:981) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926) at com.mysql.jdbc.ResultSetImpl.checkRowPos(ResultSetImpl.java:841) at com.mysql.jdbc.ResultSetImpl.getStringInternal(ResultSetImpl.java:5656) at com.mysql.jdbc.ResultSetImpl.getString(ResultSetImpl.java:5576) at nth.cumf3.nodeImport.Validator.validate(Validator.java:43) at nth.cumf3.nodeImport.Main.main(Main.java:38) What am I doing wrong here?

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  • Circular Reference exception with JSON Serialisation with MVC3 and EF4 CTP5w

    - by nakchak
    Hi I'm having problems with a circular reference when i try and serialise an object returned via EF4 CTP5. Im using the code first approach and simple poco's for my model. I have added [ScriptIgnore] attributes to any properties that provide a back references to an object and annoyingly every seems to work fine if i manually instantiate the poco's, i.e. they serialise to JSON fine, and the scriptignore attribute is acknowledged. However when i try and serialise an object returned from the DAL i get the circular reference exception "A circular reference was detected while serializing an object of type 'System.Data.Entity.DynamicProxies.xxxx'" I have tried several ways of retreiving the data but they all get stuck with this error: public JsonResult GetTimeSlot(int id) { TimeSlotDao tsDao = new TimeSlotDao(); TimeSlot ts = tsDao.GetById(id); return Json(ts); } The method below works slightly better as rather than the timeslot dynamic proxied object causing the circular refference its the appointment object. public JsonResult GetTimeSlot(int id) { TimeSlotDao tsDao = new TimeSlotDao(); var ts = from t in tsDao.GetQueryable() where t.Id == id select new {t.Id, t.StartTime, t.Available, t.Appointment}; return Json(ts); } Any ideas or solutions to this problem? Update I would prefer to use the out of the box serialiser if possible although Json.Net via nuget is ok as an alternative i would hope its possible to use it as I intended as well...

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  • Exception when retrieving record using Nhibernate

    - by Muhammad Akhtar
    I am new to NHibernate and have just started right now. I have very simple table contain Id(Int primary key and auto incremented), Name(varchar(100)), Description(varchar(100)) Here is my XML <class name="DevelopmentStep" table="DevelopmentSteps" lazy="true"> <id name="Id" type="Int32" column="Id"> </id> <property name="Name" column="Name" type="String" length="100" not-null="false"/> <property name="Description" column="Description" type="String" length="100" not-null="false"/> here is how I want to get all the record public List<DevelopmentStep> getDevelopmentSteps() { List<DevelopmentStep> developmentStep; developmentStep = Repository.FindAll<DevelopmentStep>(new OrderBy("Name", Order.Asc)); return developmentStep; } But I am getting exception The element 'id' in namespace 'urn:nhibernate-mapping-2.2' has incomplete content. List of possible elements expected: 'urn:nhibernate-mapping-2.2:meta urn:nhibernate-mapping- 2.2:column urn:nhibernate-mapping-2.2:generator'. Please Advise me --- Thanks

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  • Are C++ exceptions sufficient to implement thread-local storage?

    - by Potatoswatter
    I was commenting on an answer that thread-local storage is nice and recalled another informative discussion about exceptions where I supposed The only special thing about the execution environment within the throw block is that the exception object is referenced by rethrow. Putting two and two together, wouldn't executing an entire thread inside a function-catch-block of its main function imbue it with thread-local storage? It seems to work fine: #include <iostream> #include <pthread.h> using namespace std; struct thlocal { string name; thlocal( string const &n ) : name(n) {} }; thlocal &get_thread() { try { throw; } catch( thlocal &local ) { return local; } } void print_thread() { cerr << get_thread().name << endl; } void *kid( void *local_v ) try { thlocal &local = * static_cast< thlocal * >( local_v ); throw local; } catch( thlocal & ) { print_thread(); return NULL; } int main() try { thlocal local( "main" ); throw local; } catch( thlocal & ) { print_thread(); pthread_t th; thlocal kid_local( "kid" ); pthread_create( &th, NULL, &kid, &kid_local ); pthread_join( th, NULL ); print_thread(); return 0; } Is this novel or well-characterized? Was my initial premise correct? What kind of overhead does get_thread incur in, say, GCC and VC++? It would require throwing only exceptions derived from struct thlocal, but altogether this doesn't feel like an unproductive insomnia-ridden Sunday morning…

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  • Hibernate Exception Fixed By Alt+Tab

    - by Lee Theobald
    Hi all, I've got a very curious problem in Hibernate that I would like some opinions on. In my code if I do the following: Go to page A Click a link on page A to be taken to page B Click on data item on page B Exception thrown I get an error telling me: failed to lazily initialize a collection of role: XYZ, no session or session was closed Fair enough. But when I do the same thing but add an alt+tab in the middle, everything is fine. E.g. Go to page A Click a link on page A to be taken to page B Hit ALt+Tab to switch to another application Hit ALt+Tab to switch back to the web browser Click on data item on page B Everything is fine. I'm a little confused as to how switching focus from my application makes it act as I want it to. Does anyone have any light to shine on the subject? I don't think it's a locking issue as even if I do the second set of steps quicker than the first, still no error. It's a Seam application using Hibernate 3.3.2.GA & 3.4.0.GA.

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  • C# XNA: What can cause SpriteBatch.End() to throw a NRE?

    - by Rosarch
    I don't understand what I'm doing wrong here: public void Draw(GameTime gameTime) // in ScreenManager { SpriteBatch.Begin(SpriteBlendMode.AlphaBlend); for (int i = 0; i < Screens.Count; i++) { if (Screens[i].State == Screen.ScreenState.HIDDEN) continue; Screens[i].Draw(gameTime); } SpriteBatch.End(); // null ref exception } SpriteBatch itself is not null. Some more context: public class MasterEngine : Microsoft.Xna.Framework.Game { public MasterEngine() { graphicsDeviceManager = new GraphicsDeviceManager(this); Components.Add(new GamerServicesComponent(this)); // ... spriteBatch = new SpriteBatch(graphicsDeviceManager.GraphicsDevice); screenManager = new ScreenManager(assets, gameEngine, graphicsDeviceManager.GraphicsDevice, spriteBatch); } //... protected override void Draw(GameTime gameTime) { screenManager.Draw(gameTime); // calls the problematic method base.Draw(gameTime); } } Am I failing to initialize something properly? UPDATE: As an experiment, I tried this to the constructor of MasterEngine: spriteBatch = new SpriteBatch(graphicsDeviceManager.GraphicsDevice); spriteBatch.Begin(); spriteBatch.DrawString(assets.GetAsset<SpriteFont>("calibri"), "ftw", new Vector2(), Color.White); spriteBatch.End(); This does not cause a NRE. hmm.... UPDATE 2: This does cause an NRE: protected override void Draw(GameTime gameTime) { spriteBatch.Begin(); spriteBatch.End(); // boned here //screenManager.Draw(gameTime); base.Draw(gameTime); }

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  • When is a try catch not a try catch?

    - by Dearmash
    I have a fun issue where during application shutdown, try / catch blocks are being seemingly ignored in the stack. I don't have a working test project (yet due to deadline, otherwise I'd totally try to repro this), but consider the following code snippet. public static string RunAndPossiblyThrow(int index, bool doThrow) { try { return Run(index); } catch(ApplicationException e) { if(doThrow) throw; } return ""; } public static string Run(int index) { if(_store.Contains(index)) return _store[index]; throw new ApplicationException("index not found"); } public static string RunAndIgnoreThrow(int index) { try { return Run(index); } catch(ApplicationException e) { } return ""; } During runtime this pattern works famously. We get legacy support for code that relies on exceptions for program control (bad) and we get to move forward and slowly remove exceptions used for program control. However, when shutting down our UI, we see an exception thrown from "Run" even though "doThrow" is false for ALL current uses of "RunAndPossiblyThrow". I've even gone so far as to verify this by modifying code to look like "RunAndIgnoreThrow" and I'll still get a crash post UI shutdown. Mr. Eric Lippert, I read your blog daily, I'd sure love to hear it's some known bug and I'm not going crazy. EDIT This is multi-threaded, and I've verified all objects are not modified while being accessed

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  • Null Pointer Exception in my BroadcastReceiver class

    - by user1760007
    I want to search a db and toast a specific column on the startup of the phone. The app keeps crashing and getting an exception even though I feel as the code is correct. @Override public void onReceive(Context ctx, Intent intent) { Log.d("omg", "1"); DBAdapter do = new DBAdapter(ctx); Log.d("omg", "2"); Cursor cursor = do.fetchAllItems(); Log.d("omg", "3"); if (cursor.moveToFirst()) { Log.d("omg", "4"); do { Log.d("omg", "5"); String title = cursor.getString(cursor.getColumnIndex("item")); Log.d("omg", "6"); // i = cursor.getInt(cursor.getColumnIndex("id")); Toast.makeText(ctx, title, Toast.LENGTH_LONG).show(); } while (cursor.moveToNext()); } cursor.close(); } The frustrating part is that I don't see any of my "omg" logs show up in logcat. I only see when my application crashes. I get three lines of errors in logcat. 10-19 12:31:11.656: E/AndroidRuntime(1471): java.lang.RuntimeException: Unable to start receiver com.test.toaster.MyReciever: java.lang.NullPointerException 10-19 12:31:11.656: E/AndroidRuntime(1471): at com.test.toaster.DBAdapter.fetchAllItems(DBAdapter.java:96) 10-19 12:31:11.656: E/AndroidRuntime(1471): at com.test.toaster.MyReciever.onReceive(MyReciever.java:26) For anyone interested, here is my DBAdapter fetchAllItems code: public Cursor fetchAllItems() { return mDb.query(DATABASE_TABLE, new String[] { KEY_ITEM, KEY_PRIORITY, KEY_ROWID }, null, null, null, null, null); }

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  • i have this code but when i run it i get an exception:

    - by nisnis84
    i have this code but when i run it i get an exception: java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:8081 connect,resolve) this is the code, the server running good but the client dont work <OBJECT classid="clsid:8AD9C840-044E-11D1-B3E9-00805F499D93" width="615" height="360" codebase="http://java.sun.com/products/plugin/autodl/jinstall-1_4-windows-i586.cab#Version=1,4,0,mn"> <PARAM name="code" value="client/LlamaChat.class"> <PARAM name="archive" value="LlamaChat.jar"> <PARAM name="type" value="application/x-java-applet;version=1.4"> <PARAM name="scriptable" value="true"> <PARAM name="username" value="[replace with username]"> <PARAM name="port" value="[replace with port]"> <COMMENT> <EMBED type="application/x-java-applet;version=1.4" width="615" height="360" code="client/LlamaChat.class" archive="LlamaChat.jar" pluginspage="http://java.sun.com/j2se/1.4.1/download.html" username="nis" port="8081" <NOEMBED> No Java 1.4 plugin </NOEMBED></EMBED> </COMMENT> </OBJECT>

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  • Haskell: Dealing With Types And Exceptions

    - by Douglas Brunner
    I'd like to know the "Haskell way" to catch and handle exceptions. As shown below, I understand the basic syntax, but I'm not sure how to deal with the type system in this situation. The below code attempts to return the value of the requested environment variable. Obviously if that variable isn't there I want to catch the exception and return Nothing. getEnvVar x = do { var <- getEnv x; Just var; } `catch` \ex -> do { Nothing } Here is the error: Couldn't match expected type `IO a' against inferred type `Maybe String' In the expression: Just var In the first argument of `catch', namely `do { var <- getEnv x; Just var }' In the expression: do { var <- getEnv x; Just var } `catch` \ ex -> do { Nothing } I could return string values: getRequestURI x = do { requestURI <- getEnv x; return requestURI; } `catch` \ex -> do { return "" } however, this doesn't feel like the Haskell way. What is the Haskell way?

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  • [WPF] ExceptionValidationRule doesn't react to exceptions...

    - by Darmak
    Hi, I have an ExceptionValidationRule on my TextBox: <Window.Resources> <Style x:Key="textStyleTextBox" TargetType="TextBox"> <Style.Triggers> <Trigger Property="Validation.HasError" Value="true"> <Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Self}, Path=(Validation.Errors)[0].ErrorContent}" /> </Trigger> </Style.Triggers> </Style> </Window.Resources> <TextBox x:Name="myTextBox" {Binding Path=MyProperty, ValidatesOnExceptions=True}" Style="{StaticResource ResourceKey=textStyleTextBox}" /> and MyProperty looks like that: private int myProperty; public int MyProperty { get { return myProperty; } set { if(value > 10) throw new ArgumentException("LOL that's an error"); myProperty = value; } } In DEBUG mode, application crashes with unhandled exception "LOL that's an error" (WPF Binding Engine doesn't catch this and I think it should...). In RELEASE mode, everything works fine. Can someone tell me, why the hell is this happening? And how can I fix this?

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  • @ManyToMany Duplicate Entry Exception

    - by zp26
    I have mapped a bidirectional many-to-many exception between the entities Course and Trainee in the following manner: Course { ... private Collection<Trainee> students; ... @ManyToMany(targetEntity = lesson.domain.Trainee.class, cascade = {CascadeType.All}, fetch = {FetchType.EAGER}) @Jointable(name="COURSE_TRAINEE", joincolumns = @JoinColumn(name="COURSE_ID"), inverseJoinColumns = @JoinColumn(name = "TRAINEE_ID")) @CollectionOfElements public Collection<Trainee> getStudents() { return students; } ... } Trainee { ... private Collection<Course> authCourses; ... @ManyToMany(cascade = {CascadeType.All}, fetch = {FetchType.EAGER}, mappedBy = "students", targetEntity = lesson.domain.Course.class) @CollectionOfElements public Collection<Course> getAuthCourses() { return authCourses; } ... } Instead of creating a table where the Primary Key is made of the two foreign keys (imported from the table of the related two entities), the system generates the table "COURSE_TRAINEE" with the following schema: I am working on MySQL 5.1 and my App. Server is JBoss 5.1. Does anyone guess why?

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  • Blackberry: Getting uncaught exception java.lang.securityexception

    - by Maxim Xion
    here is my code to open an image file from SDcard in Blackberry import javax.microedition.midlet.*; import javax.microedition.lcdui.*; import java.io.*; public class DisplayAnImage extends MIDlet { private Display mDisplay; private Form mForm; private Image pngBackground; public void startApp() { try{ pngBackground = Image.createImage("file:///Media Card/test_image.png"); ImageItem img = new ImageItem("bg",pngBackground, ImageItem.LAYOUT_EXPAND,"background",ImageItem.PLAIN); mForm = new Form("MIDlet Developer Guide: Display an image."); mForm.append(img); mDisplay = Display.getDisplay(this); mDisplay.setCurrent(mForm); } catch(IOException e) { mForm.append(e.getMessage()); } } public void pauseApp() { } public void destroyApp(boolean flag) { } } While I am running this app with giving all permission to app it shows me "uncaught exception java.lang.securityexception". Please somebody help me on this. Thanks in advance.. :-)

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  • ASP.NET Image Upload Parameter Not Valid. Exception

    - by pennylane
    Hi Guys, Im just trying to save a file to disk using a posted stream from jquery uploadify I'm also getting Parameter not valid. On adding to the error message so i can tell where it blew up in production im seeing it blow up on: var postedBitmap = new Bitmap(postedFileStream) any help would be most appreciated public string SaveImageFile(Stream postedFileStream, string fileDirectory, string fileName, int imageWidth, int imageHeight) { string result = ""; string fullFilePath = Path.Combine(fileDirectory, fileName); string exhelp = ""; if (!File.Exists(fullFilePath)) { try { using (var postedBitmap = new Bitmap(postedFileStream)) { exhelp += "got past bmp creation" + fullFilePath; using (var imageToSave = ImageHandler.ResizeImage(postedBitmap, imageWidth, imageHeight)) { exhelp += "got past resize"; if (!Directory.Exists(fileDirectory)) { Directory.CreateDirectory(fileDirectory); } result = "Success"; postedBitmap.Dispose(); imageToSave.Save(fullFilePath, GetImageFormatForFile(fileName)); } exhelp += "got past save"; } } catch (Exception ex) { result = "Save Image File Failed " + ex.Message + ex.StackTrace; Global.SendExceptionEmail("Save Image File Failed " + exhelp, ex); } } return result; }

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  • Could not load SWT library on Windows 32-bit

    - by Firzen
    I am almost done with one Java project that I have been developing on Linux. Now I need to build and test it on Windows. So I have installed Eclipse on Windows XP 32-bit, and imported my project. All dependencies of project are in jar files in lib folder, and on Linux everything works well, but on Windows XP I get following error: Exception in thread "main" java.lang.UnsatisfiedLinkError: Could not load SWT library. Reasons: no swt-pi-gtk-4234 in java.library.path no swt-pi-gtk in java.library.path Can't load library: C:\Documents and Settings\firzen\.swt\lib\win32\x86\swt-pi-gtk-4234.dll Can't load library: C:\Documents and Settings\firzen\.swt\lib\win32\x86\swt-pi-gtk.dll at org.eclipse.swt.internal.Library.loadLibrary(Library.java:331) at org.eclipse.swt.internal.Library.loadLibrary(Library.java:240) at org.eclipse.swt.internal.gtk.OS.<clinit>(OS.java:22) at org.eclipse.swt.internal.Converter.wcsToMbcs(Converter.java:63) at org.eclipse.swt.internal.Converter.wcsToMbcs(Converter.java:54) at org.eclipse.swt.widgets.Display.<clinit>(Display.java:133) at gui.Frontend.<init>(Frontend.java:51) at Fighter.main(Fighter.java:18) I have searched for these DLLs, but I have failed to find them. Where can I download these DLL files? Thanks in advance.

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  • workaround for ORA-03113: end-of-file on communication channel

    - by Jefferstone
    The call to TEST_FUNCTION below fails with "ORA-03113: end-of-file on communication channel". A workaround is presented in TEST_FUNCTION2. I boiled down the code as my actual function is far more complex. Tested on Oracle 11G. Anyone have any idea why the first function fails? CREATE OR REPLACE TYPE "EMPLOYEE" AS OBJECT ( employee_id NUMBER(38), hire_date DATE ); CREATE OR REPLACE TYPE "EMPLOYEE_TABLE" AS TABLE OF EMPLOYEE; CREATE OR REPLACE FUNCTION TEST_FUNCTION RETURN EMPLOYEE_TABLE IS table1 EMPLOYEE_TABLE; table2 EMPLOYEE_TABLE; return_table EMPLOYEE_TABLE; BEGIN SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) < 'm' ) AS EMPLOYEE_TABLE) INTO table1 FROM dual; SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) >= 'm' ) AS EMPLOYEE_TABLE) INTO table2 FROM dual; SELECT CAST(MULTISET ( SELECT employee_id, hire_date FROM TABLE(table1) UNION SELECT employee_id, hire_date FROM TABLE(table2) ) AS EMPLOYEE_TABLE) INTO return_table FROM dual; RETURN return_table; END TEST_FUNCTION; CREATE OR REPLACE FUNCTION TEST_FUNCTION2 RETURN EMPLOYEE_TABLE IS table1 EMPLOYEE_TABLE; table2 EMPLOYEE_TABLE; return_table EMPLOYEE_TABLE; BEGIN SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) < 'm' ) AS EMPLOYEE_TABLE) INTO table1 FROM dual; SELECT CAST(MULTISET ( SELECT user_id, created FROM all_users WHERE LOWER(username) >= 'm' ) AS EMPLOYEE_TABLE) INTO table2 FROM dual; WITH combined AS ( SELECT employee_id, hire_date FROM TABLE(table1) UNION SELECT employee_id, hire_date FROM TABLE(table2) ) SELECT CAST(MULTISET ( SELECT * FROM combined ) AS EMPLOYEE_TABLE) INTO return_table FROM dual; RETURN return_table; END TEST_FUNCTION2; SELECT * FROM TABLE (TEST_FUNCTION()); -- Throws exception ORA-03113. SELECT * FROM TABLE (TEST_FUNCTION2()); -- Works

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  • Exception when click DataGridview tab c#, .Net 4.0

    - by Nguyen Nam
    My winform app have two tab and multi thread, one is main tab and other is log tab. I only use log tab to show logs in a datagridview control. Exception is random occurred when click to log tab (Not click to row or colunm), i have try but can not find anyway to fix it. This is the error log: Message : Object reference not set to an instance of an object. Source : System.Windows.Forms TargetSite : System.Windows.Forms.DataGridViewElementStates GetRowState(Int32) StackTrace : at System.Windows.Forms.DataGridViewRowCollection.GetRowState(Int32 rowIndex) at System.Windows.Forms.DataGridView.ComputeHeightOfFittingTrailingScrollingRows(Int32 totalVisibleFrozenHeight) at System.Windows.Forms.DataGridView.GetOutOfBoundCorrectedHitTestInfo(HitTestInfo& hti, Int32& mouseX, Int32& mouseY, Int32& xOffset, Int32& yOffset) at System.Windows.Forms.DataGridView.OnMouseMove(MouseEventArgs e) at System.Windows.Forms.Control.WmMouseMove(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.DataGridView.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) Message : Object reference not set to an instance of an object. Source : System.Windows.Forms TargetSite : Void ClearInternal(Boolean) StackTrace : at System.Windows.Forms.DataGridViewRowCollection.ClearInternal(Boolean recreateNewRow) at System.Windows.Forms.DataGridView.OnClearingColumns() at System.Windows.Forms.DataGridViewColumnCollection.Clear() at System.Windows.Forms.DataGridView.Dispose(Boolean disposing) at System.ComponentModel.Component.Dispose() at System.Windows.Forms.Control.Dispose(Boolean disposing) at System.ComponentModel.Component.Dispose() at System.Windows.Forms.Control.Dispose(Boolean disposing) at System.Windows.Forms.TabControl.Dispose(Boolean disposing) at System.ComponentModel.Component.Dispose() at System.Windows.Forms.Control.Dispose(Boolean disposing) at System.Windows.Forms.Form.Dispose(Boolean disposing) Update status code: private void updateMessage(int index, string message) { try { this.dgForums.Rows[index].Cells["ColStatus"].Value = message; System.Windows.Forms.Application.DoEvents(); } catch { } }

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  • How to use interfaces in exception handling

    - by vikp
    Hi, I'm working on the exception handling layer for my application. I have read few articles on interfaces and generics. I have used inheritance before quite a lot and I'm comfortable with in that area. I have a very brief design that I'm going to implement: public interface IMyExceptionLogger { public void LogException(); // Helper methods for writing into files,db, xml } I'm slightly confused what I should be doing next. public class FooClass: IMyExceptionLogger { // Fields // Constructors } Should I implement LogException() method within FooClass? If yes, than I'm struggling to see how I'm better of using an interface instead of the concrete class... I have a variety of classes that will make a use of that interface, but I don't want to write an implementation of that interface within each class. In the same time If I implement an interface in one class, and then use that class in different layers of the application I will be still using concrete classes instead of interfaces, which is a bad OO design... I hope this makes sense. Any feedback and suggestions are welcome. Please notice that I'm not interested in using net4log or its competitors because I'm doing this to learn. Thank you Edit: Wrote some more code. So I will implement variety of loggers with this interface, i.e. DBExceptionLogger, CSVExceptionLogger, XMLExceptionLogger etc. Than I will still end up with concrete classes that I will have to use in different layers of my application.

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  • VB.net avoiding cross thread exception with extension method

    - by user574632
    Hello I am trying to implement a solution for updating form controls without using a delegate. I am attempting to use the 1st solution on this page: http://www.dreamincode.net/forums/blog/143/entry-2337-handling-the-dreaded-cross-thread-exception/ Imports System.ComponentModel Imports System.Runtime.CompilerServices Public Module MyInvoke <Extension()> _ Public Sub CustomInvoke(Of T As ISynchronizeInvoke)(ByVal control As T, ByVal toPerform As Action(Of T)) If control.InvokeRequired Then control.Invoke(toPerform, New Object() {control}) toPerform(control) End If End Sub End Module The site gives this as example of how to use: Label1.CustomInvoke(l => l.Text = "Hello World!") But i get 'l' is not declared error. As you can see im very new to VB or any OOP. I can get the second solution on that page to work (using delegates) but i have quite a few things to do in this thread and it seems like i would need to write a new delegate sub for each thing, which seems wasteful. What i need to do is select the 1st item from a combobox, update a textbox.text with the selected item, and pass the selected item to a function. Then wait for x seconds and start again, selecting the second item. I can get it to work in a single threaded application, but i need the interface to remain responsive. Any help greatly appreciated. EDIT: OK so changing the syntax worked for the example. However if i change it from Label1.CustomInvoke(Sub(l) l.text = "hello world!") (which worked just fine) to: Dim indexnumber As Integer = 0 ComboBox1.CustomInvoke(Sub(l) l.SelectedIndex = indexnumber) I get a cross threading error as though i didnt even use this method: Cross-thread operation not valid: Control 'ComboBox1' accessed from a thread other than the thread it was created on. So now im back to where i started? Any further help very much appreciated.

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  • Do you catch expected exceptions in the controller or business service of your asp.net mvc application

    - by Pascal
    I am developing an asp.net mvc application where user1 could delete data records which were just loaded before by user2. User2 either changes this non-existent data record (Update) or is doing an insert with this data in another table that a foreign-key constraint is violated. Where do you catch such expected exceptions? In the Controller of your asp.net mvc application or in the business service? Just a sidenote: I only catch the SqlException here if its a ForeignKey constraint exception to tell the user that another user has deleted a certain parent record and therefore he can not create the testplan. But this code is not fully implemented yet! Controller:   public JsonResult CreateTestplan(Testplan testplan)   {    bool success = false;    string error = string.Empty;    try   {    success = testplanService.CreateTestplan(testplan);    }   catch (SqlException ex)    {    error = ex.Message;    }    return Json(new { success = success, error = error }, JsonRequestBehavior.AllowGet);   } OR Business service: public Result CreateTestplan(Testplan testplan) { Result result = new Result(); try { using (var con = new SqlConnection(_connectionString)) using (var trans = new TransactionScope()) { con.Open(); _testplanDataProvider.AddTestplan(testplan); _testplanDataProvider.CreateTeststepsForTestplan(testplan.Id, testplan.TemplateId); trans.Complete(); result.Success = true; } } catch (SqlException e) { result.Error = e.Message; } return result; } then in the Controller: public JsonResult CreateTestplan(Testplan testplan)   {    Result result = testplanService.CreateTestplan(testplan);       return Json(new { success = result.success, error = result.error }, JsonRequestBehavior.AllowGet);   }

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  • FTP exception 501 "pathname" more than 8 characters

    - by BigMac66
    I am trying to access a file via a URI using the FTP protocol. For obvious security reasons I had to make some changes but this is where the problems seem to be coming from. My URI is as follows: ftp://user:[email protected]/u/Bigpathname/XYZ/ABC/BigPathname/bigpathname/xyz/abc/MY_LOG.LOG And I see this exception: sun.net.ftp.FtpProtocolException: CWD Bigpathname:501 A qualifier in "Bigpathname" is more than 8 characters This is really confusing as I can access the file from a Windows 7 command line with the CD command just fine. Both one directory at a time and as a full path. I found one article mentioning that MVS file names must be 8 or fewer characters but this does not explain how I can get to these same files from my command line! They do exist there is data there that I can download manual but I can not get there via a URI in Java. PS I use .toURL().openStream() to get files on my local machine just fine, it only fails when I try to get them from my server. EDIT October 1st I am able to access files on the MVS host using FileZilla and the basic FTP client from the Windows 7 command line - but I still cannot get them from a URI/URL. I downloaded a very basic Java built FTP client and tried accessing the same file in my program from there and the path works but because my file name has a dot in it "MY_LOG.LOG" I am getting File does not exist 501 Invalid data set name "MY_LOG.LOG". Use MVS Dsname conventions. I am utterly perplexed by this...

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  • getting nullpointer exception when click on button

    - by user1315187
    I am use a button and when u click this button a text field is automatic created and button status is automatic disable but if u click on disable button text field is automatic delete and button status is changed to enable.i going through this process. public class ConfigurationScreen extends MainScreen implements FieldChangeListener{ TextField tf_text; tf_text = new TextField(TextField.TYPE_PLAIN,img_text[1],img_text[0],TextField.FIELD_HCENTER); tf_text.setWidth(Display.getWidth()/2+20); ImageButton btn_en; btn_en = new ImageButton(imgs_tmintrvl1,"enable",ImageButton.FIELD_HCENTER); ImageButton btn_dis; btn_dis=new ImageButton(imgs_tmintrvl1,"Disable",ImageButton.FIELD_HCENTER); add(btn_en); btn_en.setChangeListener(this); public void fieldChanged(Field field, int context) { if( field==btn_en) { delete(btn_en); insert(btn_dis, 4); insert(tf_text, 5); System.out.println(ex); }else if (field == btn_dis){ delete(btn_dis); delete(tf_text); insert(btn_en, 4); System.out.println("Disable Button="+ex); } } But when i run this code i am getting null pointerr exception please help me where i am making mistake. Thanks in Advance

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  • Windows: Does something temporarily grab the com ports on startup?

    - by Tim
    I have a WPF/C# app that is launched as part of the "Startup" group on a Windows Embedded Standard machine. One of the first things the app does (in its static App() method) is create a new SerialPort object for COM1. COM1 is a hardwired serial port, not a USB virtual port or anything like that. My problem is that every so often (maybe 1 out of 12) on startup, I get an exception: System.UnauthorizedAccessException: Access to the port 'COM1' is denied. There are no other applications using this port. Also, when I relaunch the app following this error, it grabs the port just fine. It's as if the com port isn't ready/set up for my app sometimes. I'm clueless on this one! Any insight is appreciated! UPDATE: I added a call to SerialPort.GetPortNames() and printout all available ports before attempting to open the port. In the failure case COM1 is indeed THERE! So, it's not that the port isn't ready. It looks like something in Windows is actually grabbing the port temporarily and blocking me.

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  • throwing exception from APCProc crashes program

    - by lazy_banana
    I started to do some research on how terminate a multithreaded application properly and I found those 2 post(first, second) about how to use QueueUserAPC to signal other threads to terminate. I thought I should give it a try, and the application keeps crashing when I throw the exception from the APCProc. Code: #include <stdio.h> #include <windows.h> class ExitException { public: char *desc; DWORD exit_code; ExitException(char *desc,int exit_code): desc(desc), exit_code(exit_code) {} }; //I use this class to check if objects are deconstructed upon termination class Test { public: char *s; Test(char *s): s(s) { printf("%s ctor\n",s); } ~Test() { printf("%s dctor\n",s); } }; DWORD CALLBACK ThreadProc(void *useless) { try { Test t("thread_test"); SleepEx(INFINITE,true); return 0; } catch (ExitException &e) { printf("Thread exits\n%s %lu",e.desc,e.exit_code); return e.exit_code; } } void CALLBACK exit_apc_proc(ULONG_PTR param) { puts("In APCProc"); ExitException e("Application exit signal!",1); throw e; return; } int main() { HANDLE thread=CreateThread(NULL,0,ThreadProc,NULL,0,NULL); Sleep(1000); QueueUserAPC(exit_apc_proc,thread,0); WaitForSingleObject(thread,INFINITE); puts("main: bye"); return 0; } My question is why does this happen? I use mingw for compilation and my OS is 64bit. Can this be the reason?I read that you shouldn't call QueueApcProc from a 32bit app for a thread which runs in a 64bit process or vice versa, but this shouldn't be the case.

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  • IntelliJ inspection -- non-thrown exception

    - by skiaddict1
    This is a follow-up question to 1832203. I'm making it a new question as well, because it seems that posting an answer to a question doesn't change its position on the java page and so I'm worried that it won't get seen. Apologies if I've just stepped on some etiquette toes. I'm an IntelliJ newbie -- started using it two days ago and I'm absolutely head-over-heels in love! One of the things I adore is the code inspections. However... In one of my classes I often create exceptions without throwing them. If I can't turn off (or downgrade) the inspection warning for this then I can see I'm going to end up ignoring inspections on at least that file (if not the entire project), which would be a real pity. I've done a search in the inspection settings for "exception", and found nothing that relates exactly, so I turned them all off just to see, and it's still doing it (even after a rebuild...BTW when are inspections redone? at save? at rebuild? ???), so I would really like some help on how to make this one into an info/typo level -- which I can then ignore. Using the free version, if that makes any difference TIA to all those experienced IntelliJ warriors out there!

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