java.lang.OutOfMemoryError even if there is enough RAM available

问题

I am trying to open a file in eclipse programmatically. the associated editor for the file is defined in an external plugin which I don't have control over the source code.

I use the code snippet shown below to open the file. However I always got

Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "AWT-Windows"

I tried to increase the memory available for eclipse run configuration, but that didn't help. Any ideas what can cause this?

    private void openFiles(final IPath filePath ) {
    PlatformUI.getWorkbench().getDisplay().asyncExec(new Runnable() {

        @Override
        public void run() {

            IWorkspace workspace = ResourcesPlugin.getWorkspace();
            IFile iFileInput = workspace.getRoot().getFileForLocation(filePath);

            IEditorInput editorInput = new FileEditorInput(iFileInput);

            IWorkbenchWindow window = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
            IWorkbenchPage page = window.getActivePage();
            try {
                iFileInput.refreshLocal(IResource.DEPTH_INFINITE, null);
            } catch (CoreException e1) {
                e1.printStackTrace();
            }
            try {
                   String editorID = "xxxxx";
                   IDE.openEditor(page, editorInput, editorID);
            } catch (PartInitException e) {
                e.printStackTrace();
            }

        }
    });
}

回答1:

Try to increase heap memory size:

If you are starting using command line

java -Xms<initial heap size> -Xmx<maximum heap size>

You can do it also through eclipse, just add the following lines in eclipse.ini or through eclipse gui configuration:

-Xms1024m   
-Xmx1024m   
-XX:MaxPermSize=256M    

回答2:

You're guessing without data.

Get a profiler like VisualVM and see what's going on with memory.

Java VM uses a generational memory model. You could have plenty of physical RAM and heap space set adequately, but still get an OOM error if perm gen fills up. See if that is happening to you.

来源：https://stackoverflow.com/questions/25348511/java-lang-outofmemoryerror-even-if-there-is-enough-ram-available