使用Eclipse的JDT,如何从类名中获取IType？

IJavaProject javaProject = JavaCore.create(ResourcesPlugin.getWorkspace().getRoot().getProject("项目名称"));

IJavaSearchScope scope = SearchEngine.createJavaSearchScope(new IJavaElement[] { javaProject });
IndexManager indexManager = JavaModelManager.getIndexManager();
IIndex index = indexManager.getIndex(scope);

IType[] types = index.findTypes(className, SearchPattern.R_EXACT_MATCH, 0, null);
if (types.length > 0) {
    IType type = types[0];
    // 对获取到的IType对象进行操作
} else {
    // 类名不存在或者无法找到对应的IType对象
}