pegadinha_java

    @Test
    public void test() {
        Map<Long,String> map = new HashMap<Long,String>();
        map.put(1L, "a");
        map.put(2L, "b");
        changeMethod(map);
        System.out.println(map.get(2L));
    }

    private void changeMethod(Map<Long, String> map) {
        Map<Long,String> otherMap = new HashMap<Long,String>();
        otherMap.put(1L,"c");
        otherMap.put(2L,"d");
        map = otherMap;
    }