When working on Maven web projects with Eclipse, m2e and m2e-wtp, Webapps can sometimes suddenly stop working, raising ClassNotFoundExceptions on every startup.

This is because the webapp lib folder is no longer published to the server. Cleaning, Publishing, Closing/opening project, restarting Eclipse, nothing restore this folder and its content. Additionally, a new warning appears in the problem view :

Classpath entry org.maven.ide.eclipse.MAVEN2_CLASSPATH_CONTAINER will not be exported or published

To solve this issue, just open .classpath at the root of the project and add the following attribute to the maven classpath :

<attribute name="org.eclipse.jst.component.dependency" value="/WEB-INF/lib"/>

Save and publish to the server.

The webapp should start again.

Source: Post from Eclipse forums http://www.eclipse.org/forums/index.php/t/262101/

Just relaying a ‘thank-you’ post from Stavros Kounis on the nebula newsgroup :

Hi all

Its was back to 2008 when we have decide to rely on nebula gallery widget for our project named “PosterGenius”[1][2].

Since then Nebula Gallery widget[3] was havy used in our application. Now PosterGenius is a finalist for the Best RCP Application for the 2010 Eclipse Community Awards.

I what to share this “recognition” of our work with the Nebula Team[4] and say a BIG “Thank you guys!!”

/stavros

[1] http://www.postergenius.com/
[2] http://skounis.blogspot.com/2010/03/nebula-gallery-widget-in-production.html
[3] http://www.eclipse.org/nebula/widgets/gallery/gallery.php
[4] http://www.eclipse.org/nebula/

It’s nice to see the Gallery widget being used in more RCP applications. This kind of feedback shows that Gallery is ready to be used in production applications, even if it is still labeled as ‘beta’ because of some missing features, like accessibility and full JFace support (Feel free to help ).

Thanks Stavros for using Nebula widgets
I’ve updated my Nebula Gallery page with screenshots and links.

The CollabNet team has made a fantastic work with the new merge client in Subclipse 1.6.x. I was used to the previous merge dialog and I was surprised how merging with SVN can be easy with a good wizard.

Let’s take a look at these screenshots :

Select merge operation

Select branch to reintegrate

Pre-merge checks

No screenshot here but if there is something wrong in the current working copy, the wizard warns you and provides quick fixes.

Merge options

Results

Merge graph

The branch and merge history can be shown in the history graph. We can see the previous merge on this test project.

Great work guys

ShareMedia and Remus information Management are two open source RCP applications which have similar features :

ShareMedia is a multi-platform photo manager. It supports several repositories such as local computer, Jabber, Picasa web or Flickr.

RIM is a free OpenSource client application for the management of information with a connection to multitude of data repositories like Flickr, Youtube or Facebook and a desktop-integration for an optimal usage for the offline management, visualization and easy accessibility of information to the user.

A few weeks ago, Tom Seidel and I decided to work on Eclipse bundles that will be shared between the two projects in order to speed up development and improve reusability of our code.

Our first goal is to define a common API which will be used by both applications and to port the existing image viewers from ShareMedia to this new API. ShareMedia has two full screen viewers including an OpenGL based one, inspired from CoverFlow from iTunes (see screencast bellow @0:55).

While these bundles are mainly targeted to ShareMedia and RIM, they can also be used in the Eclipse IDE and in any RCP application.

We now have a first implementation of the viewer API and two basic viewers. A few features are still missing and there is no background image loading so the IU may freeze a few seconds while loading large images, but it is working.

The following explains how to install the viewers in Eclipse and in an RCP application.

Installing the demo viewer into Eclipse :

The viewer has a dependency on Nebula Gallery which is not yet packaged into the feature. So you have to install the gallery widget from its update site :

http://download.eclipse.org/technology/nebula/gallery/update-N/

then install the demo viewer from ShareMedia / RIM update site :

http://smedia-rim.sourceforge.net/update/site.xml

Testing the viewer :

Select one or several image files in the package viewer / navigator view, open the context menu and select View in full screen…

Your monitors will fade to black and the first file will be displayed on your primary monitor. Commands are : ESC – Return to Eclipse , SPACE – Next image.

Multi-monitor setups are supported. Your secondary monitor will let you select the image to display on the primary monitor using a gallery of all items from your selection.

How to add a viewer to your application :

First, you will have to add the following bundles to your application

• org.sharemediarim.api : the base API plugin, always required
• org.sharemediarim.simple : the basic viewers. These are the only viewers available right now, just wait
• org.sharemediarim.viewers.adapter.file : the adapter for IFile objects. Only if you want do show eclipse resources (IFile) in the viewer.
• org.apache.sanselan : dependency of o.s.v.adapter.file, used to read image thumbnails.
• org.sharemedia.rim.viewers : Eclipse integration. Adds full screen action for IFile items in the context menu.

If you didn’t use the Eclipse integration, you can open the viewer from your code (usually in an action) :

1 – Create a viewer : a viewer can display images, but not necessary in full screen. It can also be hosted in a view :

IViewer viewer= new SampleViewer();

2 – Create a full screen viewer from the previous viewer. You can also provide additional viewers which will be displayed on secondary monitors.

final GenericFullScreenViewer fullScreenViewer = new GenericFullScreenViewer(new SampleViewer());

3 – Set the viewer’s input. Objects within the selection must implement IAdaptable and have an adapter to Image or IAdvancedImage. We provide a default Adapter for IFile in org.sharemediarim.viewers.adapter.file.

fullScreenViewer.setInput(structuredSelection);

4 – Register a listener to dispose the viewer on close. You can also reuse the viewer every time, and dispose it only on exit.

fullScreenViewer.addCloseListener(new Listener() {
public void handleEvent(Event event) {
viewer.dispose();
}});


5 – Finally, open the viewer :

fullScreenViewer.open();

Get involved :

If you are interested by using these viewers in your application or by creating new implementations, don’t hesitate to get in touch with us and help improve this API and viewers.

Project home page : http://sourceforge.net/projects/smedia-rim/

Issue tracker : http://www.remus-software.org/jira/browse/SMEDIARIM

Forum : http://sourceforge.net/forum/forum.php?forum_id=977188

On Mac OS X, Growl has become the de facto standard for all notifications. There is an opened bug asking for Growl support in SWT/RCP : Bug 209911 – [Mac] Support for Growl notifications.

The best solution would be to have a standard API for notification with support for notification plug ins (including growl) and this is exactly what is discussed on bug 209911 and on the wiki page for Platform UI/Notifications.

But for those wanting to add Growl support to their applications as soon as possible, I’ve just attached to bug 209911 a plug-in which can successfully send Growl notifications.

Growl Action

Growl Notification from Eclipse

The Growl wrapper depends on Apple’s Java/cocoa bindings, so the trick was to add external libraries to the plugin classpath :

Bundle-ClassPath: .,
external:/System/Library/Java

It works, but you should know that :

• Apple Java/Cocoa bindings are deprecated.
• This does not work with Cocoa/x86_64, probably because of the deprecation. There you get the following error :java.lang.UnsatisfiedLinkError: /usr/lib/java/libObjCJava.A.dylib: no suitable
image found. Did find: /usr/lib/java/libObjCJava.A.dylib: no matching
architecture in universal wrapper

Hopefully, the Growl wrapper is a really small class, and it should be rather easy to rewrite it with SWT’s internal Cocoa packages for someone who knows Cocoa (I don’t). If you want to take a look at the wrapper, just download my attachment to Bug 209911 and take a look at the class : com.growl.Growl.

Eclipse Galileo (3.5) will be released on June 24, 2009 and comes with a really good and easy-to-use JVM Memory Analyzer.

Memory chart

Here is a quick memory analysis walkthrough :

Creating a heap dump

You can dump the memory of a Java process anytime using jmap which is included in the JDK.

To ensure jmap is working for you, get your java process ID :
ps -Af | grep java

or, if you want to dump eclipse memory :
ps -Af | grep eclipse

Then ask jmap to output a memory summary :

jmap <pid>

Jmap output :
Attaching to process ID 356, please wait...
Debugger attached successfully.
Client compiler detected.
JVM version is 1.5.0_16-133

using thread-local object allocation.
Mark Sweep Compact GC

Heap Configuration:
(...)


If you get an error, take a look at the end of this post for a few tips.

Ok so jmap works for you. Now dump the complete memory in a file :
jmap -heap:format=b <pid>

There is now a file named heap.bin in your current directory.

Installing Memory Analyzer
Start Eclipse, use Help->Install new software… and select Memory Analyzer from the Galileo update site :

Installing Memory Analyzer

Opening the dump

Switch to Memory Analysis perspective

Perspectives : select Memory Analysis

Memory summary

You can now digg into your application heap memory and ensure that no objects is using more memory than it should. Memory Analyzer also includes really nice features like an automatic leak search :

Leak suspects report

Have fun and catch the leaks

jmap tips
If you have problems running jmap, try the following tips :

• Be sure to use the jmap binary packaged with the JVM you are running : jmap from a Java 5 JDK will not be able to dump memory from a Java 6 VM : you’ll get this stacktrace :

  Attaching to process ID 704, please wait...
Exception in thread "main" java.lang.RuntimeException: gHotSpotVMTypes was not initialized properly in the remote process; can not continue
at sun.jvm.hotspot.HotSpotTypeDataBase.readVMTypes(HotSpotTypeDataBase.java:111)
at sun.jvm.hotspot.HotSpotTypeDataBase.(HotSpotTypeDataBase.java:68)
at sun.jvm.hotspot.MacOSXTypeDataBase.(MacOSXTypeDataBase.java:35)
at sun.jvm.hotspot.bugspot.BugSpotAgent.setupVM(BugSpotAgent.java:560)
at sun.jvm.hotspot.bugspot.BugSpotAgent.go(BugSpotAgent.java:481)
at sun.jvm.hotspot.bugspot.BugSpotAgent.attach(BugSpotAgent.java:319)
at sun.jvm.hotspot.tools.Tool.start(Tool.java:146)
at sun.jvm.hotspot.tools.JMap.main(JMap.java:128)


• jmap needs high system privileges. If you can’t attach to a java process with the following error :

  Attaching to process ID 704, please wait...
attach: task_for_pid(704) failed (5)
Error attaching to process: Error attaching to process, or no such process


  …, try to use sudo : sudo jmap <pid>. (See Ken Sipe's blog for additional information)

Eclipse 3.5 RC3 is out and this release fixes the last issues (Bugs 277539 and 277437) I was seeing when running the best test suite I have, ShareMedia, on the previous 3.5 RC2 Cocoa x86_64 SWT port.

Now everything is working, even the most tricky parts such as custom widgets, Open GL with LWJGL and animations….

ShareMedia running on SWT 3.5 Cocoa x86_64

The new 3.5 release also brings some long-waited features on Mac OS X :

- Java 6 and 64 bits support

- Shell modified hint

Shell modified hint

- Shell sheet style

Shell sheet style

- Program icons are now returned in full size !!!! Program.findProgram("jpg").getImageData() returns beautiful 512×512 icons instead of 16×16, see the following gallery widget snippet :

Gallery Snippet on SWT 3.4

Gallery Snippet on SWT 3.5

UPDATE: Oh no ! this is a cocoa bug, images should still be returned in 16×16. SWT committers, please don’t fix it ! I hope this will help fixing bug 181723.

These improvements make Eclipse 3.5 an absolute must for all Mac users.

The only thing I’m still missing is the Native OSX toolbar (bug 222859)

I would like to thanks all developpers who worked very hard to create this great Cocoa port in only one year and those who keep hacking to improving Eclipse UI on Mac.

Nebula is a rather active Eclipse project even if it is maintained mostly by individuals (see Nebula statistics on Ohloh). It can also be very silent . If you’re not following the cvs commit log, the dev mailing list or open bugs, it can be hard to notice what is going on.

Here are the latest news :

• Nebula is not only an incubator for SWT : the current Nebula mission statement can sound like the Nebula widgets are unstable, otherwise they would have moved to SWT :
  

  The Nebula project is a source for custom SWT widgets and other UI components. Nebula is also an incubator for SWT. Some Nebula widgets will graduate into SWT and therefore into the main Eclipse Platform.

  The reality is different :
  – several Nebula widget were developped for real world applications and were contributed once completed in order to share the code base with the Eclipse community.

  – Additionnal stable widgets are currently being contributed from other Eclipse projects.

  – The graduation is unlikely to happen, for several *good* reasons like toolkit size and dedication to native widgets even if it contains a few custom ones.

  Tom Schindl, Nebula co-lead with Chris Gross, pointed this problem out in a recent mail to the dev list and according to the number of “+1″ he got, the statement is likely to be changed very soon.

  On the stable/unstable topic, an idea (as discussed previously on the dev list) was to provide more visibility by grouping the widgets by status (stable/alpha/dormant) and to do releases of stable ones as soon as possible.

• Nightly builds : The binary downloads have been removed from the Nebula website for some time now. The reason was simple : the build process was down and all downloads were several months old. They were also not conforming to the incubation status so we simply removed them.

  Nightly builds are now back on the download page. The build process is using althena (cbi) on build.eclipse.org and can run unit tests. As a result, junit tests results are also available alongside of the binaries.

  

  Note : we haven’t finished setting up the build process for every widget yet, more downloads will be added soon. Progress can be monitored on bug 237588.

  Our next move is to build on hudson.

• Nebula Examples : The example project page has been restored.
  

  This project is also built nightly and can be downloaded as binary or simply installed from the update site.

  An official webstart version will be available as soon as I can host it on eclipse.org. (Eclipse webmaster please comment bug 270617 ). In the meantime, you can try this webstart (hosted here on my blog, don’t kill my bandwidth ! )

• Gallery widget stable version : I’ve published a stable (not nightly) version of the Gallery widget : 0.5.2_R_0_20090418.
  

  Even if the project itself is still in incubation, this version of the Gallery widget is stable enough to be used in RCP application or plugins. Be sure to read the release notes page which points out stable/unstable features and the explaination of the incubation phase (What is Incubation) on Eclipse.org.

  With that version, a javadoc is available.

  Don’t forget to report bugs if any !

That’s all for today, I hope to have more news to blog about soon .

This is a tip for all Eclipse users on Linux :

When using content assist (Ctrl-Space), you sometime have to get your hands on the mouse to use the scrollbars in order to read the full package name of a class or to scroll the content of the javadoc to the interesting part.

On both Windows or OSX, you can simply resize the content assist window and the new size will then be used the everytime you trigger content proposal.

But on Linux, you cannot resize this window. This is caused by bug 23980. While this bug is hard to solve, there is a simple workaround for this specific issue.

Edit
${workspace_location}/.metadata/.plugins/org.eclipse.jdt.ui/dialog_settings.xml

…and change content assist size in the completion_proposal_size section


<section name="completion_proposal_size">
<item value="800" key="size.x"/>
<item value="300" key="size.y"/>
</section>


Restart Eclipse and enjoy content assist at full size.

(I helped Philippe to find the right file. He published a french version on this tip and I took care of the international one. )

I’ve just fixed bug 268743 – Gallery example need update to show latest features. As a result, you can now play with all Gallery features within the Nebula example application.

Being able to combine all options freely let me spot some problems with untested usecases :

270736 : Group selection selects the last item of the group if not using SWT.MULTI

270737 : Margin issues with animation

270934 : Decorators : Wrong position for bottom left et top right decorators

266614 :Item selection background can be visible on closed group when animations turned on

I fixed these 4 items while I was at it.

You can download this example from the nebula CVS. It works both as a view or as a stand alone application.

You can also test it from webstart. (Windows only, I’m still fighting with some issues with java web start on Linux and MacOS – bugs 270421, 270617, 270948, 270949, 270950).

update : webstart now works on linux

Next on my todo list :
- get nebula nighlty builds running for all widgets (almost done)
- host the webstart on eclipse
- add an example tab for nebula animation package.