@Test
public void listDemo(){
List<String> one = new ArrayList<String>();
one.add("111");
List<String> two = new ArrayList<String>();
two.addAll(one);
one.add("123");
one = new ArrayList<String>();
public void listDemo(){
List<String> one = new ArrayList<String>();
one.add("111");
List<String> two = new ArrayList<String>();
two.addAll(one);
one.add("123");
one = new ArrayList<String>();
}
two中添加了one之后,无论one 怎么变化,two中的数据都没有变化