Eclipse PlugIn Project get existing Projects of the workspace - eclipse

Question

I am totally confused with the plugin procedures.
To be more precise: I am struggling to access the classes/projects of my workspace. I wrote an Eclipse PlugIn Project that is supposed to access my workspace and to parse one of the projects. I actually took the code from here [Link]http://www.vogella.com/tutorials/EclipseJDT/article.html#using-the-ast!
My problem is that do not receive my projects on my workspace. With this code only the RemoteSystemsTempFiles are returned:
public class SampleHandler {
public Object execute(ExecutionEvent event) throws ExecutionException {
// Get the root of the workspace
IWorkspace workspace = ResourcesPlugin.getWorkspace();
IWorkspaceRoot root = workspace.getRoot();
// Get all projects in the workspace
IProject[] projects = root.getProjects();
// Loop over all projects
for (IProject project : projects) {
System.out.println(project.getName());
}
return null;
}
Do I access the right workspace? I want to access the workspace of my plugIn project (c:/workspace) and not the workspace of the eclipse instance that is opening when I run the project.
I also tried
IPath path = ResourcesPlugin.getWorkspace().getRoot().getLocation();
This returns C:/runtime-EclipseApplication
And
File file = new File("C://workspace");
URI location = file.toURI();
IFile[] files=ResourcesPlugin.getWorkspace().getRoot().findFilesForLocationURI(location);
The files Array's length is 0.
How can I get all of my projects?