Getting access to files in Eclipse plug-ins

There are several ways to access files in Eclipse. Here are some samples

• Getting an ImageDescriptor from a plug-in
  
• Getting a resolved URL to a resource in another plug-in
• Opening a resource in an editor
  

Getting an ImageDescriptor from a plug-in
You can get an image descriptor to an image resource via the

• UIPlugin.imageDescriptorFromPlugin("pluginId", "icons/image.png")

Getting a URL to a resource inside a plug-in
First you have to have a plug-in (Bundle). Your can get it via

• Activator.getDefault().getBundle() or
  
• Platform.getBundle("plug-in id")
  

//If you want to access your own plug-in use Activator.getDefault().getBundle()
Bundle bundle = Platform.getBundle("org.eclipse.ui");

// This line return a url looking like this, bundleentry://921/plugin.xml
URL url = bundle.getEntry("/plugin.xml");

try {
// This line resolves the bundle resource url to an explicit file url into the bundle
// The url will get to look like below,
// jar:file:C:\...\org.eclipse.ui_3.4.0.I20080610-1200.jar!/plugin.xml
URL realUrl = FileLocator.resolve(url);

} catch (IOException e) {
e.printStackTrace();
}


Opening a resource in an editor
Here is a sample on how to open the org.eclipse.ui plugin.xml in an editor.

// Start by getting an IPath to a bundle resource.
IPath path = null;
URL url = null;
try {
url = FileLocator.toFileURL( Platform.getBundle("org.eclipse.ui").getEntry("/plugin.xml"));
path = new Path(url.getPath());
} catch (IOException e) {
e.printStackTrace();
}

// Next, use the Eclipse file store to validate and pass to an editor
IFileStore fileStore = EFS.getLocalFileSystem().getStore(path);

if (!fileStore.fetchInfo().isDirectory() && fileStore.fetchInfo().exists()) {
IWorkbenchPage page = getSite().getPage();
try {
IDE.openEditorOnFileStore(page, fileStore);
} catch (PartInitException e) {
e.printStackTrace();
}
}