Where eclipse stores information about jars associated with a Library - eclipse

I've written an ant task that extracts the classpath of a project form eclipse's .classpath file - so I don't need to maintain the project's dependencies both in eclipse and in my ant file.
This ant task works great and it makes my compilation ant scripts to be very elegant, short, and the most important thing maintainable.
In Eclipse you can use a pre-defined Libraries (under project > Properties > Java Build Path > Libraries), for example: Junit, Apache Tomcat, and JRE System Library. I am not talking about a user library
Each library hold a list of jars associated with it. I can see this list by expanding the library. Foe example the Juni4 library contains 2 jars: junit.jar
What keeps me from finalizing my work is that I don't know where eclipse stores the information about the jars inside the library.
-- Yonatan

Maybe in bundles.info (the following paths are from the Helios3.6 distribution, but you can find similar paths with Galileo 3.5)
C:\Prog\Java\eclipse-SDK-3.6-win32-x86_64\eclipse\configuration\org.eclipse.equinox.simpleconfigurator\bundles.info
, where you can read:
org.eclipse.jdt.junit4.runtime,1.1.100.v20100526-0800,plugins/org.eclipse.jdt.junit4.runtime_1.1.100.v20100526-0800.jar,4,false
which references the junit.jar found in:
C:\Prog\Java\eclipse-SDK-3.6-win32-x86_64\eclipse\plugins\org.junit_4.8.1.v4_8_1_v20100427-1100\
That is consistent which what you cansee when you actually "add a Library":
alt text http://img805.imageshack.us/img805/4581/eclipseaddlib.png

Related

Define a Java 9 multi-moduled project in Eclipse

I'm trying out Java 9 Jigsaw module system (no module experience yet) and would like to use it for capsuling the classes within my project, but it's confusing.
According to this article it should be possible to have multiple modules within ONE project. I made a new project in Eclipse Oxygen (Java 9 is supported) with the same structure as shown in the article. But Eclipse keeps telling me that I must not have more than one module-info.java in a project.
I really don't know how to tell Eclipse that it should use the "multi-module-mode". And I really would appreciate not having to create a new project for every single module.
This works:
This not:
But according to this article something like that should work:
And how about deployment of a modularized project with Eclipse? There is nothing to see about the new jmod extension. Do I still export it as a runnable JAR file like before?
Notice that my questions refer to working with the IDE (no command line, I mean with an IDE that should be possible, right?) Thank you for enlightening me.
Currently, Eclipse requires you to create a separate project for each module (e. g. because each module has its own Java Build Path).
To understand this design decision, consider that Java modules correspond to OSGi bundles / Eclipse plug-ins and it has always been to have a separate project for each bundle/plug-in. If you come from the Maven world, you would probably expect a deeper folder structure instead. But modules are self-contained and combining several modules into one project would only add an additional folder level without meaning. However, Eclipse supports nested projects and so-called working sets if you need an additional folder level.
Exporting modules as images is planned for Eclipse 2019-03 (4.11), on March 20, 2019 (see Eclipse bug 518445). Exporting modules as JARs that can be used on the modulepath (-m) already works (see my video).
I don't know if this question is still open for an answer, but you can solve this problem by simply removing all source folders on the build path. At least this works for Eclipse 2021-12 version.
As you can see this is a demo project from the Official Gradle Guide Book and it has multiple modules. Each module has its own module-info.java.
project structure in IntelliJ IDEA
If I open this project in Eclipse it will give me the 'duplicated entries on module-info.java' error.
Eclipse shows the error
But if I delete all the source folders on the build path, the error is gone and the project can be built and run without problem.
project properties: Java build path
The only problem is that you have to build the project with Gradle so that it will produce the .jar of each module and you have to include them in the libraries later.
include all the .jar in libraries
I think this is probably the same solution mentioned by howlger above.

rdf using apache jena on net beans

I want to create a simple RDF graph and then try simple querying using SPARQL. Since I'm familiar with java and net beans, I want to use Apache Jena on NetBeans. I downloaded the related files from http://www.apache.org/dist/jena/ .
What should I do next to write RDF codes on net beans? i.e Should I install something or add lib files/jar files somewhere?
(Too long for a comment on Ian's reply)
Maven is easy on netbeans, and a good way to get started with everything you need (as Ian says). Here's a quick guide to start a jena project:
File -> New Project. Choose Maven then Java Application.
Pick project name, location, etc., then Finish.
Netbeans will create a new maven project and open it.
Right click on Dependencies, choose Add Dependency....
Use org.apache.jena as the Group ID, jena-core (or jena-arq if you want SPARQL) as the Artifact ID, and 2.10.1 as the Version.
Open the Dependencies folder. It ought to have a number jars present -- these are jena and its required jars. You might need to right-click on Dependencies again and choose Download Declared Dependencies to ensure jena is ready for use.
Under Source Packages you'll find App.java. Try some of the simple jena api tutorials and try running them.
You need to put the .jar files from the Jena distribution where Netbeans will find them. I don't know Netbeans, but in Eclipse I might have a lib directory in my project top-level directory, and then set the Eclipse's project classpath to include each of those .jar files. Netbeans I'm sure has something similar.
Actually what I do in Eclipse is not use downloaded jars at all, but I would use Maven to manage the dependencies for me. So I would create a pom.xml file in my project folder that stated that, among other things, my project depends on Jena, and then Maven takes care of downloading the dependencies for me. Eclipse and Maven work well together; I'd hope the same would be true of Netbeans. Setting up Maven to use Jena is described on the Jena site. However, learning Maven can be a bit of a steep curve, so if you're not ready to take that on just yet then downloading the .jar files to a project lib directory is the way to go.

scala generating jar file from scala-io to include in eclipse

I am trying to use the library scala-io in my Eclipse environment, does anyone know how do I generate a jar file, or which folder to include in my eclipse so that I can have access to the scala-io library from my project ?
EDIT:
Q: How to incorporate an external library into scala IDE?
A: Two possibilities:
Leverage SBT to build your project; that is generating jar files and maintaining dependency
Including the generted jar files directory in the IDE, project -> Properties -> Java build paths.
hth.
EDIT #2:
I found this great plugin to generate all of your dependencies in one jar file sbt-assembly
http://jesseeichar.github.io/scala-io-doc/0.4.2/index.html#!/getting-started
shows how to start with sbt or maven or with prebuild jars provided by links.
You should try to get familiar with a build system like sbt. Its cumbersome to always manually add dependencies to eclipse, especially if you have dependency chains: scala-io needs scala-io-core and arm and file etc...

Errors in exporting eclipse deployable plug-ins and fragments

I have an eclipse plug-in working fine within eclipse environment.
I wanted to export it into a jar file, so I chose Export > Deployable plug-ins and fragments.
I could get a jar file, but an error was reported.
Opening the log file, it reports that I have 1242 problems (191 errors, 1051 warnings). This is some copy from the error log.
2. ERROR in /Users/LSclipse/src/lsclipse/LSDiffRunner.java (at line 61)
import edu.washington.cs.induction.OnePipeLineScript;
^^^
The import edu cannot be resolved
----------
3. ERROR in /Users/LSclipse/src/lsclipse/LSDiffRunner.java (at line 261)
OnePipeLineScript.getMatchingForRefFinder(projName, proj1, proj1Loc
^^^^^^^^^^^^^^^^^
OnePipeLineScript cannot be resolved
Why I got errors? I had 2049 warnings, but no error when I compile the plugin in eclipse IDE.
ADDED
The main project references two other projects, and references many external libraries. I attach the package view and Java build path.
There were multiple issues involved for this problem. However, the core issue was that the project apimatching and originanalysis were not eclipse plugins but just java projects. As a result, those two projects were not included in the final jar file to break the build.
Symbolic linking the two projects into the main project
I solved this issue by symbolic link the src directory into the main eclipse plugin project.
ln -s /workspace/seal/edu.ucsc.originanalysis/src /LSclipse/originanalysis
ln -s /workspace/seal/edu.ucsc.apimatching/src /LSclipse/apimatching
From the Java Build Path/Source tab, I added those two included projects as source. Eclipse Java Missing required source folder: 'src'
Now I have eclipse plugin jar file without error.
Then click F-5 to refresh the project explorer and check they are java src directory.
Select the included projects in Build tab.
Updating bin.include and source.. in build.properties tab is important. One should understand that in bin.include the ordering is also critical. lib/cdtparser.jar and lib/cdtcore.jar should be placed prior to the user of them - origin analysis/.
Copying jar files for included project into main project
I also had to copy some jar files in those projects file into the main project, and select them in Binary Build tab.
And add tim in Runtime/Classpath tab.
Select the JavaSE-1.6 in Execution Environments.
I have lots of "Must Override a Superclass Method" errors. With the hint from this post - 'Must Override a Superclass Method' Errors after importing a project into Eclipse , I removed the J2SE-1.5 to resolve this issue.
You can not add third party libraries into class path of Java when developing a plug-in. It is the way to build standard Java application, but plug-in is a kind of OSGi bundle that has itself rule for class loading.
The correct way is adding third party libraries into the class path of your plug-in.
Add below declaration into MANIFEST.MF of your plug-in,
Bundle-ClassPath: lib/log4j-1.2.7.jar,
xml-apis.jar,
...
Check those links [1], [2] for understanding it.
This is what have a question on and see as potential solutions to potential problems.
Is this class comfing from a referenced jar or is it in the actual plugin edu.washington.cs.induction.OnePipeLineScript;
You seem to have a lot of soure folders and wondering if your build.properties file is showing any warnings and that you also have this defined for each of the source folders in your build.properties source.. = src/
Your external jar libraries appear to be in a folder that is of type source which is not correct. It should be a non-source folder (which you can tell a source folder by the package icon decorator) and you should make sure in your manifest editor that for runtime you have the lib checked so that it includes the jars in the build. To unmark it as a source folder select the drop down menu in your navigator view go to filters and uncheck .resources which will then show the .classpath file in that file you will see the folder to be kind="src" (i believe) remove that.
Somehow it also looks like you have linked source folders which is a practice I would not suggest and am not sure if that will cause problems when exporting the plugin. If you can avoid linked source folders that would be better.
Also it seems like you are confusing java build path configuration for plain java applications with plugins running in OSGI which is not configured through java build path but your manifest.editor So as a rule of thumb if its a plugin don't even bother trying to configure the java build path because OSGI is different, that could be causing issues as well
Select "Use class files complied in the workspace" in Options works for me.

What's the best way to manage dependencies with CounterClockwise/Eclipse?

I have a dependency on clj-record in my CounterClockwise project. What's the best way to manage this? Copy the source code or compile to a JAR and add it as a referenced library?
There are tools to help you:
http://github.com/technomancy/leiningen <- project based
http://github.com/liebke/cljr <- dependencies not project based
http://github.com/ninjudd/cake <- alternative build tool
Assuming your dependencies are available in a Maven repo (like central or clojars), you have a couple of options.
First, if you're using Leiningen, there is an eclipse plugin for it now that will manage project dependencies for you, based on the dependencies you define in your project.clj file. The plugin is in beta now, but has been working great for me so far. (Note that it uses Leiningen 2.0 under the covers, though that detail won't matter for many (most?) simple cases.)
If you're using Maven, the m2eclipse plugin makes it so that the dependencies you declare in your Maven pom.xml are automatically added to your eclipse project's build path, and are therefore available in CCW REPLs and such.
there seems to be no pattern for specifying dependencies apart from hacking the code into your project or building a jar externally.
Of course you can, just as with any java project. While dependency resolution isn't tied into eclipse (yet), once you retrieve the deps (via one of the command line tools nickik listed), you can specify which jars are to be included in the java build path of your eclipse project:
Retrieve the deps via cake, leiningen, etc.
Refresh the eclipse project so you see the deps (usually in the lib directory)
Highlight the jars you want eclipse to know about
Right-click, select Build Path > Add to Build Path
That's it. You can fiddle with the build path by going to the Java Build Path section of the project's properties window.