DiscoverJavaModelFromLibrary discover = new DiscoverJavaModelFromLibrary();
    String path = "/tmp/test.jar";
    IFile jar = ... ;

    IPackageFragmentRoot root = JavaCore.createJarPackageFragmentRootFrom(jar);
    IProgressMonitor monitor = new NullProgressMonitor();

    /* create model */
    discover.discoverElement(root,  monitor);
    Resource resource = discover.getTargetModel();
    Model model = (Model) resource.getContents().get(0);

    /* list methods */
    EList<ClassFile> classFiles = model.getClassFiles();
    for (ClassFile classFile : classFiles) {
      System.out.println(classFile.getName());
    }

public void getModel(String jar) throws RemoteException {

		if (jar == null)
			return;

		try {
			/* Open eclipse project */
			IWorkspace ws = ResourcesPlugin.getWorkspace();
			IProject project = ws.getRoot().getProject("FeatureExtractor");
			IProgressMonitor monitor = new NullProgressMonitor();

			/* Create a new project, in case there isn't one */
			if (!project.exists()) {
				IProjectDescription description = project.getDescription();
				description.setNatureIds(new String[] {"org.eclipse.jdt.core.javanature"});
				project.setDescription(description, monitor);
				project.create(monitor);
				if (!project.isOpen())
					project.open(monitor);	
			}

			/* Create a link to the jar file, which is outside the project */
			IPath location = new Path(jar);
			IFile file = project.getFile(location.lastSegment());
			file.createLink(location, IResource.REPLACE, monitor);

			/* Create Java project, and 
			 * add location (jar file) to the build path */
			IJavaProject javaProject = JavaCore.create(project);
			IPath filePath = project.getWorkspace().getRoot().getLocation().append(file.getFullPath());

			/* Set project fragment roots */
			Set<IClasspathEntry> e = new HashSet<IClasspathEntry>();
			e.addAll(Arrays.asList(javaProject.getRawClasspath()));			
			boolean entryExist = false;
			for (IClasspathEntry c : javaProject.getRawClasspath()) {
				if ( filePath.toOSString().matches(c.getPath().toOSString()) ) {
					entryExist = true;
					break;
				}
			}			
			IVMInstall vmInstall = JavaRuntime.getDefaultVMInstall();
			LibraryLocation[] locations= JavaRuntime.getLibraryLocations(vmInstall);
			for (LibraryLocation element : locations) {
				e.add(JavaCore.newLibraryEntry(element.getSystemLibraryPath(), null, null));
			}
			for (IPackageFragmentRoot r : javaProject.getPackageFragmentRoots()) {
				if ( filePath.toOSString().matches(r.getPath().toOSString()) ) {
					entryExist = true;
					break;
				}
			}	
			if (!entryExist) {
				e.add(JavaCore.newLibraryEntry(filePath, null, null));
			}
			javaProject.setRawClasspath(e.toArray(new IClasspathEntry[e.size()]), monitor);

			/* Create discover for jar file */
			DiscoverJavaModelFromLibrary discover = new DiscoverJavaModelFromLibrary();
			IPackageFragmentRoot root = JavaCore.createJarPackageFragmentRootFrom(file);
			if (root == null) {
				System.out.println("Error: Fragment root is null. Aborting...");
				return null;		
			}

			/* Create model from jar file */
			discover.discoverElement(root, monitor);
			Resource resource = discover.getTargetModel();
			// Model model = (Model) resource.getContents().get(0);

			/* Save Model XMI */
			exportModelToXMI(resource, filePath.toOSString().replace(".jar", ".xmi"));

		} catch (CoreException e) {
			e.getMessage();
			e.printStackTrace();
		} catch (DiscoveryException e) {
			e.getMessage();
			e.printStackTrace();
		} catch (ParserException e) {
			e.getMessage();
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}