Eclipse插件：启动后立即运行代码

Question

I want to show a message right after the plugin starts. If I put my code at the end of the Activator.start() method I get an error (probably because the needed resources are not loaded yet).

The errors look like this:

!MESSAGE While loading class "de.stefansurkamp.package.ClassIWantToLoad", thread "Thread[main,6,main]" timed out waiting (5006ms) for thread "Thread[Worker-2,5,main]" to finish starting bundle "MyPlugin_1.0.0.qualifier [302]". To avoid deadlock, thread "Thread[main,6,main]" is proceeding but "de.stefansurkamp.package.ClassIWantToLoad" may not be fully initialized.
!STACK 0
org.osgi.framework.BundleException: State change in progress for bundle "reference:file:/C:/Users/Stefan/workspace/MyPlugin/" by thread "Worker-2".
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.beginStateChange(AbstractBundle.java:1088)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:298)
    at org.eclipse.osgi.framework.util.SecureAction.start(SecureAction.java:478)
    at org.eclipse.osgi.internal.loader.BundleLoader.setLazyTrigger(BundleLoader.java:263)
    at org.eclipse.core.runtime.internal.adaptor.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:109)
    [...]
Caused by: org.eclipse.osgi.framework.internal.core.AbstractBundle$BundleStatusException
    ... 53 more
Root exception:
org.eclipse.osgi.framework.internal.core.AbstractBundle$BundleStatusException
    [...]

If needed, I can provide a full stack trace.

So is there any method that runs right after start() is finished?

EDIT: Using a job and org.eclipse.ui.startup

According to greg's recommendations I created a Job inside a class which is loaded by the org.eclipse.ui.startup extension point.

This is how my earlyStartup() method looks like:

@Override
public void earlyStartup() {        
    Job clearPrefsJob = new Job("clearPrefsJob") {

        @Override
        protected IStatus run(IProgressMonitor monitor) {
            try {
                DataStorage dataStorage = new DataStorage();
                dataStorage.clearPrefs();
                System.out.println("Everything gone.");
            }
            catch (StorageException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return null;
        }

    };

    clearPrefsJob.addJobChangeListener(new IJobChangeListener() {
        (All of the IchangeEvents here)
    });

    clearPrefsJob.setPriority(Job.BUILD);
    clearPrefsJob.schedule();

My console prints Everything gone. and my debugging message for the job being done (by the job change listener).

But right after that I get an error message:

!ENTRY org.eclipse.core.jobs 4 2 2014-07-29 11:53:12.481
!MESSAGE An internal error occurred during: "clearPrefsJob".
!STACK 0
java.lang.NullPointerException
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:69)

Additionally my testing environment shows the following error message:

'clearPrefsJob' has encountered a problem.
   An internal error occured during: "clearPrefsJob".
   java.lang.NullPointerException

I have no idea where the NullPointerException in this part of the code should come from because everything worked fine before using a job.

Solution:

Looks like the problem was using return null . When using return Status.OK_STATUS (or similar) everything went fine.

Answer 1

You could create a Job ( org.eclipse.core.runtime.jobs.Job ) in the start method and schedule it to run.

If your code needs to interact with the UI use UIJob .

Alternatively you could use the org.eclipse.ui.startup extension point to have a class run early in Eclipse startup (but this may be too early for what you want to do so a Job may still be necessary).

You could also use an OSGi service for your class.