How to programatically add classpaths to an eclipse project

This is very easy, All you need is the name of the project or IProject it self and the jar path list.

   public static void setClassPathToNewLibs(String projectName,String[] jarPathList){
        IProject project = ResourcesPlugin.getWorkspace().getRoot().getProject(projectName);
        try {
            IJavaProject javaProject = (IJavaProject)project.getNature(JavaCore.NATURE_ID);
            IClasspathEntry[] rawClasspath = javaProject.getRawClasspath();
            List list = new LinkedList(java.util.Arrays.asList(rawClasspath));
            for(String path:jarPathList){
                String jarPath = path.toString();
                boolean isAlreadyAdded=false;
                for(IClasspathEntry cpe:rawClasspath){
                    isAlreadyAdded=cpe.getPath().toOSString().equals(jarPath);
                    if (isAlreadyAdded) break;
                }
                if (!isAlreadyAdded){
                    IClasspathEntry jarEntry = JavaCore.newLibraryEntry(new Path(jarPath),null,null);
                    list.add(jarEntry);
                }
            }
            IClasspathEntry[] newClasspath = (IClasspathEntry[])list.toArray(new IClasspathEntry[0]);
            javaProject.setRawClasspath(newClasspath,null);
        } catch (CoreException e) {
            e.printStackTrace();
        }

}

Should work for any kind of eclipse project I guess.