http://w3facility.org/question/how-to-programmatically-new-a-java-class-which-implements-sepecified-interface-in-eclipse-plugin-development/
OpenNewClassWizardAction wizard = new OpenNewClassWizardAction();
wizard.setOpenEditorOnFinish(false);
NewClassWizardPage page = new NewClassWizardPage();
page.setPackageFragmentRoot(sourceFolder, false);
wizard.setConfiguredWizardPage(page);
wizard.run();
return (IType) wizard.getCreatedElement();
add more here:
check which button use is clicked,
if finished button is clicked : wizard.getCreatedElement() will not return null ,otherwise it will return null value.