Package org.eclipse.swt.internal

Class ExceptionStash

java.lang.Object

org.eclipse.swt.internal.ExceptionStash

All Implemented Interfaces:

AutoCloseable

public class ExceptionStash
extends Object
implements AutoCloseable

The intent of this class is to insulate SWT from exceptions occurring in user's listeners, so that SWT remains stable and does not accidentally crash JVM or enter some very broken state. The supposed use is:

void someSwtInternalFunction() {
     // Make a stash to collect all exceptions from user listeners
     try (ExceptionStash exceptions = new ExceptionStash ()) {
         // Perform some action that may call a throwing user's listener
         try {
            sendEvent(SWT.SomeEvent);
         } catch (Error | RuntimeException ex) {
             exceptions.stash (ex);
         }

         // Do some important SWT stuff that you would normally do in
         // 'finally' clause. With 'ExceptionStash' you can interleave
         // important things with listeners without making code ugly.
         MakeSureThingsDontBreak();

         // Perform another action that may call a throwing user's listener.
         // Done in an independent 'try' block to make sure that all events
         // are sent regardless of exceptions in some of the listeners.
         try {
            askWidgetToSendMoreEvents();
         } catch (Error | RuntimeException ex) {
             exceptions.stash (ex);
         }

         // Exiting from 'try' statement will close ExceptionStash and
         // re-throw collected exception. If there are multiple exceptions,
         // all subsequent ones will be added as 'Throwable.addSuppressed()'.
     }
 } 

Constructor Summary

Constructors

Constructor	Description
ExceptionStash()

Method Summary

Modifier and Type	Method	Description
void	close()
void	stash(Throwable throwable)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ExceptionStash

public ExceptionStash()

Method Details

stash

public void stash(Throwable throwable)

close

public void close()

Specified by:

close in interface AutoCloseable