java的值传接

java的值传递

@Test    public void TestCollection() {User user = new User();user.setUsername("Tom");List<User> ulist = new ArrayList<User>();ulist.add(user);for (User u : ulist) {    u.setUsername("TomCat");}for (User u : ulist) {    System.out.println(u.getUsername());}    }    

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class User {    private String username;    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }}

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运行结果：

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TomCat

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    @Test    public void TestIntCollection() {Integer x = new Integer(1);List<Integer> ilist = new ArrayList<Integer>();ilist.add(x);for (Integer i : ilist) {    i = 25;}for (Integer i : ilist) {    System.out.println(i);}    }

?运行结果：

1

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