Develop Reference

Lucene NoSuchMethodError in Eclipse Plugin

Edit: This question is solved. For some reason there indeed was another version of the Lucene files in the plugins directory of Eclipse.
I'm trying to use Lucene in an Eclipse plugin. It's methods are supposed to be called from another plugin.
It works great as long as I run the project as a Java Application. But when I try to call a method from the other plugin, I get the following error:
java.lang.NoSuchMethodError: org.apache.lucene.store.FSDirectory.open(Ljava/nio/file/Path;)Lorg/apache/lucene/store/FSDirectory;
Of course the method does indeed exist as it runs perfectly fine as a Java Application. Therefore I guess I have to do something plugin-specific to make it work.
I added the necessary Lucene-jars (lucene-analyzers-common-5.3.1 and lucene-core-5.3.1) to the dependencies of my plugin. I also added org.apache.lucene.store to the Exported Packages of my plugin (as suggested by Eclipse so the plugin which calls the method can catch the LockObtainFailedException). That's everything I've done regarding Lucene.
Can someone tell me what I forgot / don't know about? (If it's not obvious, I am completly new to Eclipse plugins)
Edit:
I've also tried to add the jars directly to the plugin which is calling the Lucene-method (by adding the paths to Bundle-ClassPath in the manifest). Didn't change anything.
I've also read that such a problem may occur due to another version of Lucene being somewhere in my classpath. I made sure that's not the case.

For some reason there indeed was another (older) version of the Lucene files in the plugins directory of Eclipse. These were the problem. I deleted them and removed the version tag in the manifest.

Info about version dependancies of enterprise java libraries

I am new to enterprise application developement and trying to create a REST server with Spring REST, JPA taking to mySQL database and Javascript on the client side. As I see loads of opensource libraries doing specific task, I started off with using 'maven project' with different 'arch type' (which is nothing but predefined POM with relevent libraries as I understand) provided by Eclipse. But I often run into version mismatch issues, in many cases found specific solution to that perticular libraries in StackOverflow or other sites.
Hence I started looking for a information these version dependancies such as, this version of JPA works with that version of Hibernate library and so on. I checked maven repository of major libraries, I did not find such information so far.
My queries are:
Where can I find these information about the versions dependancies?
Are these pre defined POM in eclipse reliable? Who owns them, where can I get last modified dates on these maven 'arch types'? (I find the ones I choose having fairly old version of libraries).
If I have to start off on my own creating a Maven dependacies, where will I get information about what are the dependent libraries, for example, if I need spring MVC, for sure it needs java servlet library. I am worried becuase the maven 'spring-mvc-jap' arch type whooping 50 libaries as dependancies.(Coming from embeded domain, I find to too hard to digest :D). So not sure if it is the right way.
Please correct if I am missing anything in my understanding.

You can find this information, if you are using maven and some IDE you can go to the dependancy and make click un > and this will show the librarys used for this dependancy or if you want to use the console you have http://maven.apache.org/plugins/maven-dependency-plugin/examples/resolving-conflicts-using-the-dependency-tree.html this will show the same that the IDE.
After normally in the documentation of the library used, you can find some doc about the dependancy about this.
Other solution is get the .jar and use 7zip to see the POM and know the dependancy used.
And for finish my answer if the IDE tell you that you dont have x dependancy normally you have to add this because any of the other dependancy used have it (they used only for the compiling task), but sometime somes projet change a lots of code between the version .a to .b so you will have some problem using the version .b, at this moment i didnt find one good and easy way to fix this, only using the way that i told you (only if i found some problem in the compilation)

3> I am not sure how it works in eclipse but in IntelliJ IDEA when you start using some class without proper dependency IDEA suggest you to add proper dependency automatically. The same approach should be in eclipse.

maven: exclude jar from JDK

So, I've been searching SO for hours and hours and I'm completely running into the brick wall here.
My problem's quite simply: I've got a (pretty big) project that I'd like being built with Maven (so I can automate it all a bit). Everything works fine so far except for one major problem.
I've got a dependency called "java-plugin" - I don't know exactly the origin or the author, but it was in the dependencies of a dependency of mine - I added it to our own Nexus third party repository with the name the original jar was given.
This plugin gets added from my Nexus without any problems, but it has the following structure:
- netscape
-- javascript
JSException.class
JSObject.class
JSUtil.class
-- security
ForbiddenTargetException.class
ParameterizedTarget.class
Principal.class
Privilege.class
PrivilegeManager.class
PrivilegeTable.class
Target.class
UserDialogHelper.class
UserTarget.class
- sun
-- plugin
...
-- plugin2
...
- com.sun.java.browser.plugin2
...
What's the problem? As long as I was working in an Eclipse based project, I placed my JDK as the "last" one on my classpath. Now it's Maven and apparently Maven places the JDK first. In my JDK I have the jfxrt.jar (part of Java FX). This one also contains a netscape.javascript.JSObject object (and also a netscape.javascript.JSException object). It doesn't contains a netscape.javascript.JSUtil object on the other hand. So Maven picks up the JSObject and the JSException from the JDK library, and the other classes he picks up from my own java-plugin dependency.
Of course both classes are not the same. Of course now I get compilation errors as the java-plugin dependency contains a 'getWindow' method in the JSObject class where the JDK library doesn't.
The ideal situation would be to exclude jfxrt.jar from Maven, but I have absolutely no idea on how to do that. Any other solution would do too, as long as I could get this one to build with Maven. Note: I'd rather not want to use the "endorse" mechanism in Java if possible, as that would require uploading this library to several different servers over and over again and would cause huge delays in deployment (as we'd always have to sent the file to our support team for yet another upload).
Thanks!
EDIT
So, my plugin dependency is something which is also in the JDK - even better! I don't need my java-plugin, I've got enough with my JDK which includes plugin.jar automatically (it's in my ${java.home}/lib/plugin.jar).
Now I have this situation:
As you can see, the jfxrt.jar comes first, before the plugin.jar. I can see why Maven, or Java more generally, stops looking as soon as it finds the first netscape.javascript.JSObject (which is in jfxrt.jar). But I really need it to load the second JSObject class (which unfortunately happens to be in the same package and with the same name). How the hell am I supposed to do this? And why did this work without a charm in Eclipse, when I wasn't using Maven, and why doesn't it work in IntelliJ, together with Maven?
Thanks in advance!

Ok, so I figured it out. Apparently this was much more of an IntelliJ issue than it was of a classpath issue.
So IntelliJ automatically adds the full JDK (including all jars in /jre/lib) to the classpath - first, before all the Maven dependencies. So that caused my project to be going weird: I had a netscape.javascript.JSObject in jfxrt.jar, in plugin.jar and in my Maven plugin (these jars were added in this order). The first JSObject that was found was the one in jfxrt.jar, which caused the problem.
It worked in Eclipse as there, I could alter the classpath order and had added my Maven plugin BEFORE the JDK - so the order became java-plugin.jar (first one, correct JSObject class), jfxrt.jar, plugin.jar.
It would have worked when I'd use an older JDK - this jfxrt.jar was only added in JDK7.
It works on Jenkins, if I still have my java-plugin.jar from Maven, because Jenkins does not automatically add the JDK libraries (only the core). That was how I cleared it out:
I removed my own java.plugin.jar and replaced it by a dependency on plugin.jar.
<dependency>
<groupId>com.sun.jdk</groupId>
<artifactId>plugin</artifactId>
<version>${version.java-plugin}</version>
<type>jar</type>
<scope>system</scope>
<systemPath>${java.home}/lib/plugin.jar</systemPath>
</dependency>
I still had the problem in IntelliJ, but arrived to remove the jfxrt.jar from the imported JDK libraries in IntelliJ itself - which does change the .iml file but of course not anything that would be of use for Jenkins. (You can edit these settings by right clicking on the External Libraries > < 1.7> folder in the Project Browser, and then clicking Open Library Settings).
Once jfxrt.jar was removed, everything worked. I reasoned that this wouldn't change anything in Jenkins, but on the other hand, then the problem maybe wouldn't even exist on Jenkins. So I simply tried and commited my code to SVN to build it on Jenkins.
Magically, it works now on Jenkins too. I tried and removed my dependency on plugin.jar, then I get the classical "could not find symbol" compilation error on Jenkins - while I don't get that error in IntelliJ, due to the automatically importing of the JDK on the classpath.
Long story short: By editing my project settings in IntelliJ I got it working locally, by simply trusting Maven I got it working on Jenkins, the way it should.

JBoss Library, ClassNotFoundException and the Other Problems

We were using tomcat for our projects here and we started to think of using JBoss. But i couldnt manage to run any of our projects. I tried to solve the errors, looking for them all over the internet but when i solve an error, the other error comes after it. Im tired of which library should i remove not to clash with JBoss own libraries, hibernate jars, richfaces jars or whatever. Anyone has an ultimate solution for this situation? Im really starting to give up.
By the way, im trying jboss 5.

In this case, I'd take the opposite approach: remove everything and add which is missing.
I'd start by moving all external libraries to an "external jars" directory, move back jars which are surely not found in JBoss (you can check $JBOSS/common/lib, $JBOSS/lib, $JBOSS/server/<yourtype>/lib directories). If you ever need to use Tomcat again, I'd copy the "external jars" directory contents to $TOMCAT/lib.

It's usually pain when you mix up your own webapp libraries with container shared libraries. I would suggest to remove all the shared libraries and try to run it having all the proper jars in your webapp. Once this work you might move on ... If you have any remaining specific problems go ahead and post it :)

Eclipse and JBoss not refreshing or rebuilding

I'm having this problem in eclipse (EE) when I change things in my code (even something as simple as the text I'm printing using println) it doesn't get applied. I'm using JBoss and when I rerun the servlet, nothing happens.
Any idea how I can force JBoss/Eclipse to do this? I can't preview anything so it's really annoying if I want to test some new code.
Thanks!

Eclipse publishes the newer versions of your application periodically (its called the automatic publish feature). Either the interval is too large, or you're not waiting sufficiently long enough for re-deployment, or automatic publishing of the application has been disabled.
Sometimes, despite ensuring the above, Eclipse might still not publish the newer classes, in which case you might want to perform a clean build, which causes the newly built classes to be loaded into JBoss.

Sorry to ask such a basic question: Do you save your changes before testing?
Eclipse uses its own compiler to check for syntax errors while you are editing, but you have to save the file before the edits take effect in the application.
I only ask because this could be confusing if you are new to Eclipse, having changed from a different IDE. File permission settings can also prevent your files from being saved or built.

Working on EJB deployed in JBoss with Eclipse IDE.
We have ANT build file, in which first old project is deleted from JBoss,
then compiling classes, & building proper directory structure & deploy as .ear - .sar again in JBoss directory.
Stop JBoss, run build file, start JBoss.
Its a good practice to have a build file to deploy project.