refreshLocal on IResource throws exception - eclipse

I am trying to programmatically refresh a folder inside the project for my Eclipse plugin. I have also included a simple semaphore rule in the Job. Here is the code:
public class MutexRule implements ISchedulingRule {
public boolean isConflicting(ISchedulingRule rule) {
return rule == this;
}
public boolean contains(ISchedulingRule rule) {
return rule == this;
}
}
...
Job refreshJob = new Job("Refreshing...") {
public void run() {
IResource myFolder = ...
if(myFolder != null)
myFolder.refreshLocal(DEPTH_INFINITE, null);
}
};
refreshJob.setRule(
When I schedule two jobs, and run the refresh, I get the following exception:
Attempted to beginRule: P/test, does not match outer scope rule: ...
What am I missing?
What is a possible solution / workaround?

The error you are getting is because the IResource you are refreshing also has a scheduling rule (IResource implements ISchedulingRule). When there are nested scheduling rules the outer rule must 'contain' the inner rule - your MutexRule doesn't do this.
Because the resource already has a scheduling rule there is no need to set a rule on your job.
refreshLocal does not have to in a Job but if it is run from the UI thread a progress monitor should be provided using IProgressService or similar.
Update: refreshLocal can generate many resource changed events, to minimize these use a WorkspaceModifyOperation or a WorkspaceJob:
Job job = new WorkspaceJob("Refreshing") {
public IStatus runInWorkspace(IProgressMonitor monitor) {
monitor.beginTask("", IProgressMonitor.UNKNOWN);
try {
resource.refreshLocal(monitor);
}
finally {
monitor.done();
}
return Status.OK_STATUS;
}
});
or
WorkspaceModifyOperation op = new WorkspaceModifyOperation() {
#Override
protected void execute(IProgressMonitor monitor) throws CoreException {
resource.refreshLocal(monitor);
}
};
If you are in a wizard page you can run the WorkspaceModifyOperation with:
getContainer().run(true, true, op);
elsewhere you can use:
IProgressService service = PlatformUI.getWorkbench().getProgressService();
service.run(true, true, op);
Even better is to use the Eclipse IFile and IFolder APIs to create files and folders, in this case refreshLocal is not required.

Related

class member returns null after osgi bind method

My problem is that in the main class I have some osgi references that work just fine when the class is call. But after that all the references became null. When I close the main windows and call shutdown method, the hubService reference returns null. What do I do wrong here?
private void shutdown() {
if(hubService == null) {
throw new NullPointerException();
}
hubService.shutdownHub(); // why is hubService null?
}
// bind hub service
public synchronized void setHubService(IHubService service) {
hubService = service;
try {
hubService.startHub(PORT, authenticationHandler);
} catch (Exception e) {
JOptionPane.showMessageDialog(mainFrame, e.toString(), "Server", JOptionPane.ERROR_MESSAGE);
System.exit(0);
}
}
// remove hub service
public synchronized void unsetHubService(IHubService service) {
hubService.shutdownHub();
hubService = null;
}
If a field can be read and written by multiple threads, you must protect access to read as well as write. Your first method, shutdown, does not protect the read of hubService so that the value of hubService can change between the first read and the second read. You don't show the declaration of the hubService field. You could make it volatile or only read when synchronized (on the same object used to synchronized when writing the field). Then your shutdown implementation could look like:
private volatile IHubService hubService;
private void shutdown() {
IHubService service = hubService; // make a copy of the field in a local variable
if (service != null) // use local var from now on since the field could have changed
service.shutdownHub();
}
I assume your shutdown method is the DS deactivate method? If so, why do you shutdown in the unset method as well in the shutdown method?
Overall the design does not seem very sound. The IHubService is used as a factory and should return some object that is then closed in the deactivate method. You made the IHubService effectively a singleton. Since it must come from another bundle, it should handle its life cycle itself.
Since you also do not use annotations, it is not clear if your set/unset methods are static/dynamic and/or single/multiple. The following code should not have your problems (exammple code with bnd annotations):
#Component public class MyImpl {
IHubService hub;
#Activate
void activate() {
hubService.startHub(PORT, authenticationHandler);
}
#DeActivate
void deactivate() {
hubService.shutdown();
}
#Reference
void setHub(IHubService hub) { this.hub = hub; }
}

Is there a way to have Eclipse flash its taskbar icon once a time consuming task finishes?

I often minimize Eclipse to read or work on something else for a few minutes while I wait for it to do something (e.g., run a large JUnit test suite, synchronize a huge number of files with a repo, run a long Ant build, etc.). I have to check back every 30 seconds or so to see if it's finished yet. I would like Eclipse to alert me, preferably by blinking its taskbar icon, after it finishes a time consuming operation. Are there any settings or plugins that can make this happen?
I believe is you have Mylyn installed, this should be enabled by default for Windows 7. See here and here. Regarding the post-build actions, I do not know of any existing Eclipse plugins that do this. However, I have not exhaustively searched the marketplace. However, this could be accomplished with existing Eclipse APIs but it would require someone to author a new Eclipse plugin.
The Eclipse Platform jobs framework has an API called IJobManager. A developer could write a new Eclipse plugin that could use this API to listen for job changes and do the following:
Create an eclipse plugin, register a listener to IJobManager on startup.
Once any interesting job is completed, it could fire off some external task/script using normal java process execution API in the JDK
This all could be accomplished in one Java file, probably less than 500 lines long.
You could use this template to setup a basic Eclipse plugin project including build system and have it built and ready to install into your existing Eclipse.
Update I just found a maven archetype for building eclipse plugins with tycho here. It would be my recommendation for someone new to building an eclipse feature/updatesite.
You can create a new plugin project and create this kind of functionality for yourself. The
IJobchangeListener from the Eclipse Jobs API is probably very interesting for you.
The IJobChangeListener is an interface where you can receive notifications for the different type of job states.
I have created a class called JobListener which adds the IJobchangeListener to the JobManager. With the action SampleAction you can register or unregister the listener. that means, if the listener is registered and your application is minimized you will be notified with a MessageDialog (no blinking taskbar).
I found a link where someone made his swing application blink. This functionality should be included in the method public void done(final IJobChangeEvent event). I haven't done this in my test class.
You can also get additional information about the Job with
event.getJob();
Here you are able to check the Job name:
String jobName = event.getJob().getName();
The name of the Job is human readable, for example "Collecting garbage", "Update for Decoration Completion", "Building workspace", etc.
The JobListener class.
/**
* A job listener which may be added to a job manager
*/
public class JobListener {
private MyJobListener listener = null;
private IWorkbenchWindow window = null;
private boolean active = false;
public JobListener(IWorkbenchWindow window) {
this.window = window;
}
/**
* register the job listener
*/
public void register() {
listener = new MyJobListener(window);
IJobManager jobMan = Job.getJobManager();
jobMan.addJobChangeListener(listener);
active = true;
}
/**
* unregister the job listener
*/
public void unregister() {
IJobManager jobMan = Job.getJobManager();
jobMan.removeJobChangeListener(listener);
active = false;
}
public boolean isActive() {
return active;
}
class MyJobListener implements IJobChangeListener {
private IWorkbenchWindow window;
public MyJobListener(IWorkbenchWindow window) {
this.window = window;
}
#Override
public void sleeping(IJobChangeEvent event) {
}
#Override
public void scheduled(IJobChangeEvent event) {
}
#Override
public void running(IJobChangeEvent event) {
}
#Override
public void done(final IJobChangeEvent event) {
window.getShell().getDisplay().asyncExec(new Runnable() {
#Override
public void run() {
if(window.getShell().getMinimized()) {
MessageDialog.openInformation(
window.getShell(),
"Test",
"Job " + event.getJob().getName() + " done.");
}
}
});
}
#Override
public void awake(IJobChangeEvent event) {
}
#Override
public void aboutToRun(IJobChangeEvent event) {
System.out.println("About to run: " + event.getJob().getName());
}
}
}
I called this class from a class called SampleAction.java
public class SampleAction implements IWorkbenchWindowActionDelegate {
private IWorkbenchWindow window;
private JobListener listener;
/**
* The constructor.
*/
public SampleAction() {
}
public void run(IAction action) {
if(listener.isActive()) {
listener.unregister();
MessageDialog.openInformation(
window.getShell(),
"Lrt",
"Unregistered");
}
else {
listener.register();
MessageDialog.openInformation(
window.getShell(),
"Lrt",
"Registered");
}
}
public void selectionChanged(IAction action, ISelection selection) {
}
public void dispose() {
}
public void init(IWorkbenchWindow window) {
this.window = window;
this.listener = new JobListener(window);
}
You can get started with eclipse plugin development by creating a new plugin project:
File > New > Project > Plugin Project
I used the Hello World plugin project template to test the code above.

Eclipse Plugin, How can I know when IResourceDeltaVisitor ends processing tree nodes?

I wrote an Eclipse Plugin that basically allow a programmer to select a Java source from the Project Explorer and by selecting the corresponding DropDown menu option it will creates an interface .java file based on the one selected.
Everything works fine, but now I need to program the update part of the job.
The update requierement is simple, I need to listen for changes and identify that the sources that have the interface generated have been modified and recreate the interface file.
To do this I wrote a class that implements IResourceChangeListener interface.
That class looks like:
public class DTOChangeListener implements IResourceChangeListener {
private List<UpdatedUnit> updatedUnits;
public DTOChangeListener() {
super();
this.updatedUnits=new ArrayList<UpdatedUnit>();
}
#Override
public void resourceChanged(IResourceChangeEvent event) {
try{
if(event.getType() == IResourceChangeEvent.POST_CHANGE){
event.getDelta().accept(this.buildVisitor());
}
}catch(CoreException ex){
ex.printStackTrace();
}
}
protected IResourceDeltaVisitor buildVisitor(){
IResourceDeltaVisitor result=new IResourceDeltaVisitor() {
#Override
public boolean visit(IResourceDelta resDelta) throws CoreException {
String resName=resDelta.getResource().getName();
if(resName==null || resName.equals("")){
return true;
}
String[] splits=resName.split("\\.");
String name = splits[0];
if(name.contains("PropertyAccess")){
return false;
}
String interfaceName=name + "PropertyAccess";
String interfaceFile=interfaceName + ".java";
IResource res=resDelta.getResource();
if((res instanceof IFolder) || (res instanceof IProject)){
// Avoid Folder & Project Nodes
return true;
}
IProject project=res.getProject();
if(project!=null){
if(project.isNatureEnabled("org.eclipse.jdt.core.javanature")){
IJavaElement element=JavaCore.create(res);
if(element instanceof ICompilationUnit){
ICompilationUnit unit=(ICompilationUnit)element;
IPath path=res.getProjectRelativePath().removeLastSegments(1);
IResource propertyAccess=project.findMember(path.append(interfaceFile));
if(propertyAccess!=null){
UpdatedUnit updatedUnit=new UpdatedUnit(project, path, unit);
updatedUnits.add(updatedUnit);
return false;
}
}
}
}
return true;
}
};
return result;
}
public List<UpdatedUnit> getUpdatedUnits() {
return updatedUnits;
}
}
I add the Listener to the Workspace, now the question I have is:
How can I know when the updatedUnits List is completed in order to proccess the list with my own code?
One posible answer to this question would be, don't worry, the:
event.getData().accept(this.buildVisitor());
will block until proccessing of the visitor finish.
but at least is not documented like it would.
Any ideas would be appreciated.
Thanks in Advance.
Daniel
Unless it's documented to not block, it blocks.

How can I correctly update a progress bar for an operation of unknown duration within an Eclipse wizard?

I have implemented a wizard for my Eclipse plug-in, showing several pages. One of these pages needs some lengthy initialization, that means it consists of a SWT table, which needs to be populated by information coming from an external source. This source needs to be activated first (one single method call that returns after a couple of seconds - I can not know in advance how long it will take exactly), before it can be used as input for for the table viewer. This initialization is currently done by the table model provider when it needs to access the external source for the first time.
Therefore, when I enter the wizard page, I would like to show a dummy progress bar that just counts up for a while. My approach was the following, but unfortunately does not work at all:
private void initViewer() {
IRunnableWithProgress runnable = new IRunnableWithProgress() { // needed to embed long running operation into the wizard page
#Override
public void run(IProgressMonitor monitor) throws InvocationTargetException, InterruptedException {
SubMonitor progress = SubMonitor.convert(monitor);
Thread thread = new Thread() {
#Override
public void run() {
Display.getDefault().syncExec(new Runnable() {
public void run() {
viewer.setInput(ResourcesPlugin.getWorkspace().getRoot()); // this will make the table provider initialize the external source.
}
});
}
};
thread.start();
while(thread.isAlive()) {
progress.setWorkRemaining(10000);
progress.worked(1);
}
progress.done();
}
};
try {
getContainer().run(false, false, runnable);
} catch(Exception e) {
throw new Exception("Could not access data store", e);
}
}
This method gets then invoked when the wizard page's setVisible()-method is called and should, after a couple of seconds, set the viewer's input. This, however, never happens, because the inner-most run()-method never gets executed.
Any hints on how to deal with long-running (where an exact estimate is not available) initializations in Eclipse wizards would be very appreciated!
I have given below a simple example on how to use IRunnableWithProgress along with a ProgressMonitorDialog to perform a task of unknown quantity. To start with, have an implementation to IRunnableWithProgress from where the actual task is performed. This implementation could be an inner class.
public class MyRunnableWithProgress implements IRunnableWithProgress {
private String _fileName;
public MyRunnableWithProgress(String fileName) {
_fileName = fileName;
}
#Override
public void run(IProgressMonitor monitor) throws InvocationTargetException, InterruptedException {
int totalUnitsOfWork = IProgressMonitor.UNKNOWN;
monitor.beginTask("Performing read. Please wait...", totalUnitsOfWork);
performRead(_fileName, monitor); // This only performs the tasks
monitor.done();
}
}
Now, a generic implementation to ProgressMonitorDialog can be created as below which could be used for other places where a progress monitor dialog is required.
public class MyProgressMonitorDialog extends ProgressMonitorDialog {
private boolean cancellable;
public MyProgressMonitorDialog(Shell parent, boolean cancellable) {
super(parent);
this.cancellable = cancellable;
}
#Override
public Composite createDialogArea(Composite parent) {
Composite container = (Composite) super.createDialogArea(parent);
setCancelable(cancellable);
return container;
}
}
Having got the required implementation, the task can be invoked as below to get it processed with a progress dialog.
boolean cancellable = false;
IRunnableWithProgress myRunnable = new MyRunnableWithProgress(receivedFileName);
ProgressMonitorDialog progressMonitorDialog = new MyProgressMonitorDialog(getShell(), cancellable);
try {
progressMonitorDialog.run(true, true, myRunnable);
} catch (InvocationTargetException e) {
// Catch in your best way
throw new RuntimeException(e);
} catch (InterruptedException e) {
//Catch in your best way
Thread.currentThread().interrupt();
}
Hope this helps!
I assume the reason why it's "not working" for you is that the preparation of input is done in UI thread meaning that the progress bar cannot be updated. A better approach is to prepare input in advance and only set input to viewer after that.

Using IoC container as a service locator for HttpHandler

This question relates to my other post.
Ok so after a bit more messing around I decided to do it this way. Which seems to work fine when I run it, although I'm getting the following error in NUnit: Could not load file or assembly 'Castle.Core, Version=1.0.3.0, Culture=neutral, PublicKeyToken=407dd0808d44fbdc' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) So not sure what is happening there???
Just wanted to know what others thought about the design and if there are any obvious 'no no's' or improvements. I.e. Is the constructor of the base handler a good place to instantiate the windsor component or is there a better place to do this? As I said in the original post the idea behind doing things this way was to keep the components nicely decoupled and to make unit testing easy. I should also add I'm new to unit testing, mocking. Thanks!
public abstract class BaseHttpHandler : IHttpHandler
{
private HttpContext _httpContext;
private ILogger _logger;
private IDataRepository _dataRepository;
protected HttpRequest Request { get { return _httpContext.Request; } }
protected HttpResponse Response { get { return _httpContext.Response; } }
protected bool IsRequestFromUAD { get { return Request.UserAgent == null ? false : Request.UserAgent.Equals("UAD"); } }
protected ILogger Logger { get { return _logger; } }
protected IDataRepository DataRepository { get { return _dataRepository; } }
public virtual bool IsReusable { get { return false; } }
public BaseHttpHandler()
{
var container = new WindsorContainer(new XmlInterpreter(new ConfigResource("castle")));
_logger = container.Resolve<ILogger>();
_dataRepository = container.Resolve<IDataRepository>();
}
public void ProcessRequest(HttpContext context)
{
_httpContext = context;
ProcessRequest(new HttpContextWrapper(context));
}
public abstract void ProcessRequest(HttpContextBase context);
}
public class UADRecordHttpHandler : BaseHttpHandler
{
public override void ProcessRequest(HttpContextBase context)
{
if (IsRequestFromUAD)
{
using (var reader = new StreamReader(context.Request.InputStream))
{
string data = reader.ReadToEnd();
if (Logger != null)
Logger.Log(data);
if(DataRepository != null)
DataRepository.Write(data);
context.Response.Write(data);
}
}
else
ReturnResponse(HttpStatusCode.BadRequest);
}
}
That's a very bad thing to do, what you're doing here. You should have one instance of the container per application, while with this code you will have one per each request.
About the error in NUnit: make sure you don't have other versions of Castle assemblies in the GAC. If so, uninstall them.
About your BaseHttpHandler: the problem with this implementation is that you're creating a new container. Instead, use a single container per application, like Krzysztof said. Use a static service locator, e.g. CommonServiceLocator. (I never recommend this but it's one of the few places where it does make sense).