The finally statement is executed, but the return value isn’t affected. The execution order is: Code before return statement is executed Expression in return statement is evaluated finally block is executed Result evaluated in step 2 is returned Here’s a short program to demonstrate: using System; class Test { static string x; static void Main() … Read more
You can only make changes to WinForm controls from the master thread. You need to check whether InvokeRequired is true on the control and then Invoke the method as needed. You can do something like this to make it work: public void CheckUnusedTabs(string strTabToRemove) { if (TaskBarRef.tabControl1.InvokeRequired) { TaskBarRef.tabControl1.Invoke(new Action<string>(CheckUnusedTabs), strTabToRemove); return; } TabPage tp … Read more
Unlike Java 9 and later, Java 8 does not provide a static factory method for this scenario. The default constructor can be used instead: CompletableFuture<T> future = new CompletableFuture<>(); future.completeExceptionally(exception);
When you work with I/O in Java most of the time you have to handle IOException which can occur any time when you read/write or even close the stream. You have to put your sensitive block in a try//catch block and handle the exception here. For example: try{ // All your I/O operations } catch(IOException … Read more
It’s most likely because the current request is an ajax (asynchronous) request. The exception handler which you’ve there is designed for regular (synchronous) requests. The proper way to change the view in case of an ajax exception is as follows: String viewId = “/error.xhtml”; ViewHandler viewHandler = context.getApplication().getViewHandler(); context.setViewRoot(viewHandler.createView(context, viewId)); context.getPartialViewContext().setRenderAll(true); context.renderResponse(); This is however … Read more
Use ex.ToString() to get the full stack trace. You must compile with debugging symbols (.pdb files), even in release mode, to get the line numbers (this is an option in the project build properties).
In JUnit 4 it can be easily done using ExpectedException rule. Here is example from javadocs: // These tests all pass. public static class HasExpectedException { @Rule public ExpectedException thrown = ExpectedException.none(); @Test public void throwsNothing() { // no exception expected, none thrown: passes. } @Test public void throwsNullPointerException() { thrown.expect(NullPointerException.class); throw new NullPointerException(); } … Read more
The typical method most people have learned to handle exceptions is vulnerable to missing trapped exceptions: eval { some code here }; if( $@ ) { handle exception here }; You can do: eval { some code here; 1 } or do { handle exception here }; This protects from missing the exception due to … Read more
std::streambuf * buf; std::ofstream of; if(!condition) { of.open(“file.txt”); buf = of.rdbuf(); } else { buf = std::cout.rdbuf(); } std::ostream out(buf); That associates the underlying streambuf of either cout or the output file stream to out. After that you can write to “out” and it will end up in the right destination. If you just want … Read more
They are the Win32 equivalent to Unix signals, and let you catch CPU exceptions such as access violation, illegal instruction, divide by zero. With the right compiler options (/EHa for Visual C++), C++ exceptions use the same mechanism as stack unwinding works properly for both C++ (user) exceptions and SEH (OS) exceptions. Unlike C++ exceptions, … Read more