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| <TITLE>Handling errors from a launched program</TITLE> |
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| <h3>Handling errors from a launched program</h3> |
| <p>If you have defined your own type of launch configuration, it's likely that |
| you will want to handle errors or other status information that arises during the |
| running of the program. For example, you may want to prompt or alert the |
| user when certain types of errors occur during a launch, or provide information |
| messages for certain status changes in the program. Since it's good |
| practice to separate UI handling from core function, you do not want to have |
| direct references from your launch delegate to status handling classes.</p> |
| <p>This problem is addressed by the |
| <a href="../reference/extension-points/org_eclipse_debug_core_statusHandlers.html"><b>org.eclipse.debug.core.statusHandlers</b></a> |
| extension point. It allows you to associate a status handler with a |
| specific status code. Using this extension point, you can define all of |
| the possible status and error codes in your launch delegate and core classes, |
| while registering unique handlers for the different status codes from another |
| plug-in.</p> |
| <p>The extension point does not designate any association between a status |
| handler and a launch configuration. It is up to the implementation of the |
| launch delegate to detect errors, find the appropriate status handler, and |
| invoke it. The extension merely provides a registry so that the status |
| handlers can be found for particular status codes. |
| <a href="../reference/api/org/eclipse/debug/core/DebugPlugin.html"><b>DebugPlugin</b></a> |
| provides a utility method for obtaining a specific status handler.</p> |
| <pre> |
| IStatusHandler handler = DebugPlugin.getDefault().getStatusHandler(status);</pre> |
| <p>Status handlers should implement <a href="../reference/api/org/eclipse/debug/core/IStatusHandler.html"><b>IStatusHandler</b></a>. |
| The status handling class is specified in the extension definition, along with |
| its associated status code and the plug-in that is expected to generate the |
| status codes.</p> |
| <p>The following markup shows how the Java tools declare status handlers:</p> |
| <pre><extension point = "org.eclipse.debug.core.statusHandlers"> |
| <statusHandler |
| id="org.eclipse.jdt.debug.ui.statusHandler.vmConnectTimeout" |
| class="org.eclipse.jdt.internal.debug.ui.launcher.VMConnectTimeoutStatusHandler" |
| plugin ="org.eclipse.jdt.launching" |
| code="117"> |
| </statusHandler> |
| ... |
| </extension></pre> |
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