public void test1(Object obj) {
		test2(obj);
	}

	public void test2(Object obj) {
		test3(obj);
	}

	public void test3(Object obj) {
		test4(obj);
	}

	public void test4(Object obj) {
		if(obj instanceof String) {
			System.out.println("多重接受类型不变");
		}
	}