CODEWITHSUNDEEP
javaeclipsejareclipse-plugin
Fifi
Fifi

Reputation: 497

Where are the custom class loader generated by Eclipse when using a jar inside a jar?

With Eclpise (and other tools), it is possible to include a dependency jar inside another jar (see this answer). When Eclipse do that, it generates a custom class loader, because "classic" class loaders are not able to find a class in a jar that is inside another jar.

To create my jar (package.final.jar), I :
- Imported the jar to include (dep.jar) inside a libs/ folder in my project ;
- Added dep.jar in MANIFEST.MF -> Runtime -> Classpath (so it added the line Bundle-ClassPath: libs/dep.jar,. to my manifest) ;
- Exported my project as a deployable plug-ins and fragments.

And package.final.jar contains only this structure :

-META-INF/MANIFEST.MF
-package/-class1.class
         -class2.class
         .
         .
         .
-libs/dep.jar

So I am wondering, where is the custom class loader created by Eclipse ?

Upvotes: 0

Views: 217

Answers (2)

greg-449
greg-449

Reputation: 111142

For Eclipse plug-ins the Bundle-ClassPath entry in the plug-in's MANIFEST.MF tells the Eclipse / OSGi system which classes and jars in the main plug-in jar are part of the class path.

There is no extra code added to the plug-in jar, the Eclipse class loaders deal with the included jars.

So you can build the jar however you like as long as the MANIFEST.MF is correct. Using maven + Eclipse tycho is common these days.

Upvotes: 1

Sebastian
Sebastian

Reputation: 51

You should have the following folder inside your jar: org/eclipse/jdt/internal/jarinjarloader

Containing the Classloader etc.:

  • JIJConstants.class
  • JarRsrcLoader$ManifestInfo.class
  • JarRsrcLoader.class
  • RsrcURLConnection.class
  • RsrcURLStreamHandler.class
  • RsrcURLStreamHandlerFactory.class

You can also check it if you look into the META-INF/MANIFEST.MF-File to see what Main-Class is set

Upvotes: 0

Related Questions