IJavaSearchScope scope = SearchEngine.createWorkspaceScope();
  SearchEngine engine = new SearchEngine();
  SearchPattern pattern = SearchPattern.createPattern("some.Clazz",
            IJavaSearchConstants.TYPE, IJavaSearchConstants.DECLARATIONS,
            SearchPattern.R_EXACT_MATCH);
  SearchRequestor requestor = new SearchRequestor() {
    public void acceptSearchMatch(final SearchMatch match) throws CoreException {
      TypeDeclarationMatch typeMatch = (TypeDeclarationMatch) match;
      IJavaElement type = (IJavaElement) typeMatch.getElement();
      IFile file = (IFile) match.getResource();

      // do something

    }
  };
  try {
    engine.search(pattern, new SearchParticipant[] { SearchEngine.getDefaultSearchParticipant() }, scope, requestor, new NullProgressMonitor());
  } catch (final CoreException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
  }