public void invokeMethod() {
		try {
			Class<?> clazz = Class.forName("com.rock.reflect.User");
			User u = (User) clazz.newInstance();
			Method m = clazz.getMethod("setUserName", String.class);
			m.invoke(u, "rock");
			
			System.out.println(u.getUserName());
			
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (NoSuchMethodException e) {
			e.printStackTrace();
		} catch (SecurityException e) {
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (InvocationTargetException e) {
			e.printStackTrace();
		}
		
	}