Why doesn't Eclipse show default proposals for JSTL code? - eclipse

I have the following problem:
I am working on a .jsp file on eclipse. My problem is that Eclipse somehow doesn't support default proposals for jstl code <c:[anything] and gives out the warning Unknown tag(<c:[anything]>). What's strange about it is that syntax highlighting works perfectly fine for JSTL code and for different code (Java, PHP, HTML...) there are default proposals. My servlet container is Tomcat and I've already copied the file jstl.jar in [folder]/webapps/ROOT/WEB-INF/lib/ but didn't help.
When I take a look at Eclipse->Window->Preferences->Web->JSP Files->Editor->Content Assist the checkboxes JSP Proposals, JSP Java Proposals and JSP Template Proposals are checked.
I feel like it's actually pretty obvious to figure out where the problem is but I just don't get it!


There are some event that it would trigger eclipse to validate files. You can rebuild eclipse project. or open problems viewer, and delete the problem which you can make sure the problem is not problem, if you really import the jstl.jar, next time it wouldn't warn you.


I managed to solve the problem. I still don't konw what it actually was but I just reinstalled tomcat (I'm working on a lubuntu system) and this time I didn't do it manually by extracting a .tar.bz2 file but via apt-get install ... . Then I created a new eclipse project and told it to use tomcat as servlet container. Then it worked right away so I assume that there was just something wrong with the way I installed tomcat before (maybe some variable didn't point to the correct directory or so).

Related

How to recover java folder in NetBeans 8.0>Tools>Templates

I accidentally deleted the java folder in Tools -> Templates in NetBeans 8.0. Now it does not show me the option to make a Java class. I reinstalled netbeans, but it did not help.
Could you please help me to recover it?

Close NetBeans IDE, go to NetBeans userdir, then to config/templates directory and delete Classes_hidden file.
When NetBeans IDE is started again templates for Java are back.

An easy to recover your Java template is to go to Tools->Templates and delete another template at random (say the HTML one) then click the Revert to Default button at the right and your HTML and Java templates will be recovered.
P.S. I'm guessing you were trying to remove that author: thing in the template, so a good way to do that is by going to Tools->Templates->Java->Java class->Open in Editor and you can modify freely your template.

Can´t run acceleo uml2java example

I´m beginning with Acceleo.
I installed eclipse-modeling-luna-M6-win32.
Then i installed acceleo by update on eclipse.
(is there any better option?)
Trying to use the uml2java example.
To run it i tried to run org.eclipse.acceleo.examples.uml2java.
It gave me:
Error
Couldn't load class org.eclipse.acceleo.examples.uml2java.main.Uml2java from project org.eclipse.acceleo.examples.uml2java
Couldn't load class org.eclipse.acceleo.examples.uml2java.main.Uml2java. Check that its containing package is exported.
I did not change the code.
I checked the MANIFEST and it has on the runtime: org.eclipse.acceleo.examples.uml2java.main
I also saw that there is an UI project that as i understand is a plugin but i don´t know what to do with it (so that it will create a new menu on eclipse).
Any help is appreciated!!
Thanks.

it worked using eclipse indigo with the latest acceleo. i don´t know if it´s possible to use a more recent eclipse version. also works with eclipse kepler.

This fixed the problem for me. Try adding the "bin/" directory to the Classpath in the Manifest file.
Right click the MANIFEST.MF file and "Open With >" "Plug-in Manifest Editor".
This gives some tabs at the bottom. Use the "Runtime" tab. On the bottom right of this screen there is a place to edit the classpath. Add "bin/".
I got this idea from Etienne's answer in: Can't generate java from UML using Acceleo in Eclipse

Eclipse IDE - Open Call Hierarchy is empty/broken

What should I do, if the "Open Call Hierarchy" is broken (empty for every method in a project)? It only shows the name of the method I wanted to see the call hierarchy for. This happens for all methods I try, even though they are all called by other methods.
It is very useful for code navigation. I do not know how to work without it!
I've tried:
Opening eclipse.exe -clean -refresh
Restarting Eclipse
Closing and reopening the project
Updating the project
Renaming the .metadata file
I've checked that it searches the whole workspace, and there are no filters on.

The following may help:
Calling eclipse with eclipse.exe -clean -refresh forces Eclipse to rebuild the index. After that the feature worked again.
Closing and re-opening the project.

I also tried the suggestions above, as well as the hint given here: http://mschrag.blogspot.co.at/2009/01/open-type-cant-find-your-class.html
Nothing worked until today when I found out that I am a donkey...
I once configured a filter in the "Call Hierarchy" view and so no entries were shown because filtered out. Once I removed / disabled the filter everything worked fine again.

When you go to the eclipse bug report for this issue, somebody says, you should install over the Market place the Java 12 support.
When I installed it, it was working properly again

Also, you can try to delete the workspace and get it recreated. Make sure all your projects are backed up.

For Kepler and PDT (PHP IDE) it is broken in at least PDT 3.2.0 and 3.3.0 (tried them both). The fix is in 3.3.1 and updating to that was all I had to do get the call hierarchy working again.
(apologies, I'm not yet allowed to add comments, however this should prove handy to many)

In my case it seemed my workspace was contaminated.
Opening/closing projects and starting with clean did not fix. I had to start off a new workspace.
Fedora 20, Eclipse Kepler.

I have the same behavior with eclipse Kepler (4.3.2).
I found out, that there is a bug with methods with signature of:
void get(Object o)
Object get(Object o)
In the eclipse Error Log view I find the following exception:
java.lang.NullPointerException
at org.eclipse.jdt.internal.core.search.matching.ClasspathSourceDirectory.directoryTable(ClasspathSourceDirectory.java:52)
at org.eclipse.jdt.internal.core.search.matching.ClasspathSourceDirectory.findClass(ClasspathSourceDirectory.java:109)
at org.eclipse.jdt.internal.core.search.matching.JavaSearchNameEnvironment.findClass(JavaSearchNameEnvironment.java:146)
at org.eclipse.jdt.internal.core.search.matching.JavaSearchNameEnvironment.findType(JavaSearchNameEnvironment.java:185)
at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.askForType(LookupEnvironment.java:145)
at org.eclipse.jdt.internal.compiler.lookup.PackageBinding.getTypeOrPackage(PackageBinding.java:197)
at org.eclipse.jdt.internal.compiler.lookup.Scope.getTypeOrPackage(Scope.java:2799)
at org.eclipse.jdt.internal.compiler.lookup.Scope.getType(Scope.java:2556)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.getType(MatchLocator.java:899)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.getMethodBinding0(MatchLocator.java:955)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.getMethodBinding(MatchLocator.java:907)
at org.eclipse.jdt.internal.core.search.matching.MethodLocator.matchMethod(MethodLocator.java:327)
at org.eclipse.jdt.internal.core.search.matching.MethodLocator.resolveLevel(MethodLocator.java:664)
at org.eclipse.jdt.internal.core.search.matching.ClassFileMatchLocator.locateMatches(ClassFileMatchLocator.java:209)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.process(MatchLocator.java:1699)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1143)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1184)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1301)
at org.eclipse.jdt.internal.core.search.JavaSearchParticipant.locateMatches(JavaSearchParticipant.java:95)
at org.eclipse.jdt.internal.core.search.BasicSearchEngine.findMatches(BasicSearchEngine.java:231)
at org.eclipse.jdt.internal.core.search.BasicSearchEngine.search(BasicSearchEngine.java:515)
at org.eclipse.jdt.core.search.SearchEngine.search(SearchEngine.java:584)
at org.eclipse.jdt.internal.corext.callhierarchy.CallerMethodWrapper.findChildren(CallerMethodWrapper.java:155)
at org.eclipse.jdt.internal.corext.callhierarchy.MethodWrapper.performSearch(MethodWrapper.java:301)
at org.eclipse.jdt.internal.corext.callhierarchy.MethodWrapper.doFindChildren(MethodWrapper.java:232)
at org.eclipse.jdt.internal.corext.callhierarchy.MethodWrapper.getCalls(MethodWrapper.java:84)
at org.eclipse.jdt.internal.ui.callhierarchy.DeferredMethodWrapper.getCalls(DeferredMethodWrapper.java:65)
at org.eclipse.jdt.internal.ui.callhierarchy.DeferredMethodWrapper.fetchDeferredChildren(DeferredMethodWrapper.java:79)
at org.eclipse.ui.progress.DeferredTreeContentManager$1.run(DeferredTreeContentManager.java:235)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)
In the end, it looks like a bug in this version:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=401272
I assume, that upgrading at least to version 4.4 (Luna) will solve this problem.

In my case I was trying to get the call hierarchy of a method in the derived class of an abstract class. The requested method was declared abstract in the base class.
When I opened the call hierarchy directly on the abstract method instead of the implemented one, everything worked well. (Eclipse Neon).

My problem was that Open Call Hierarchy was searching only the project not the entire Workspace.
So I had to click on the small down arrow (in the Call Hierarchy view window on the right; it is the "View Menu" arrow -- a triangle pointing down) in Call Hierarchy view, set the Search Scope > Workspace.

Tried everything in all the answers here, but none of them worked for me. Later I figured out that this was a bug in Eclipse 2019-03 (https://bugs.eclipse.org/bugs/show_bug.cgi?id=545293). Try to upgrade your eclipse or install a newer version.
For me installing a newer version(latest version Eclipse 2019-09) solved the problem.

I tried many answers all were great, it helped many except few and I was in few.
My eclipse version is 2019-03(4.11.0). This is which has a bug. Which can be fixed by add-ons.
Go to the Eclipse Marketplace and search for plugin java 12 Support for Eclipse 2019-03(4.11)… and install it. On completion of installation restart the eclipse. Hopefully this will fix the problem. Have a nice day.

If the call Hierarchy is not opening, it might be because of the project is not imported as a java project, rather it would be displayed in the file stucture. You may want to enable the project facet through:
right click on the project -> project facet.
If you dont see anything listed, you need
configure the project facet -> Apply -> ok.

Eclipse JRE Definition not including core classes

I am trying to lnclude an additional JDK (really JRE) to my eclipse project as i need to build against the IBM Java 5 JRE.
When I add the root folder of the jre it appears as if the core java class jars are not being added and only the jars in \lib\ext are being added. That is problem 1.
The next issues is I can't even manually add the jars by adding external jars to the runtime library. The reason being when I hit ok to save off the changes and then hit ok to the preferences dialog. The changes do not truly save. I open up the jre definition dialog again and only the jars in \lib\ext are there again.
Is this an eclipse bug? Is anybody finding similar results?
I'd really like to figure out where these preferences are stored so I can manually edit the file if need be.
As a side note, I have had a similar experience with not being able to save .pmd rule preferences and having to edit them manually in the backend. Though I suspect that bug is on the PMD developers.
Anyway any help on this is greatly appreciated.
Thanks.

Mysterious Eclipse javadoc problem

I had a problem with finding Java docs in Eclipse. I seem to have fixed the problem, but I'm posting this for two reasons: I would like to know why I had the problem in the first place and perhaps my method of fixing it might be useful to someone else having a similar problem.
I created a simple Java project in Eclipse (Helios on Windows 7) and selected the JavaSE-1.6 JRE. Then I created a source file and imported java.util.GregorianCalendar. When I hovered over GregorianCalendar, I was getting the message:
This element has no attached source and the Javadoc could not be found in the attached Javadoc
None of the methods of GregorianCalendar seemed to have any Javadoc, either. Other standard Java classes (even others in java.util, like ArrayList) didn't have this problem; only GregorianCalendar. Everything seemed set up properly in the project settings. The Javadoc location set in the Java Build Path was http://java.sun.com/javase/6/docs/api/.
I managed to restore correct behavior by temporarily switching to JavaSE-1.7 and then back. Evidently something got reset and all is well. While I'm happy that things are now working, I don't like being clueless as to how they got messed up in the first place.
Can anyone provide any insights into this?

I think general support relies on the presence of a src.zip in your JDK directory, which is detected when you autosearch a directory for Java installations. It could be missing. Not sure if online Javadocs are used.

I'm using Eclipse Juno on a Windows 7 64-bit (with a 32-bit JDK) but i think it will also apply to your Eclipse version:
Download JDK docs zip file to your Desktop folder;
Right-click on the file, choose Properties and unblock it;
Move the file to a location of your choice. I normally move it to the JDK folder;
Open Eclipse and go to Window->Preferences->Java->Installed JREs;
Select your JDK installation and press Edit;
Select the rt.jar file and click "Javadoc Location..." button;
Select the "Javadoc in archive" radio button;
Set the archive path by browsing to the JDK docs zip file;
Set the "Path within archive" to "docs/api" (without the quotes).
Enjoy! ;)