list替换某一项需要遍历比对再set到对应的position

package com.zncm.list;

import java.util.ArrayList;

import org.w3c.dom.ls.LSInput;

public class ListChange {

class User {

int id;

int age;

String name;

public User(int id, int age, String name) {

super();

this.id = id;

this.age = age;

this.name = name;

}

public User() {

// TODO Auto-generated constructor stub

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

@Override

public String toString() {

return "User [id=" + id + ", age=" + age + ", name=" + name + "]";

}

}

public static void main(String[] args) {

// TODO Auto-generated method stub

new ListChange().initList();

}

private void initList() {

// TODO Auto-generated method stub

ArrayList<User> list = new ArrayList();

User u1 = new User(1, 1, "22");

User u2 = new User(2, 2, "22");

User u3 = new User(3, 3, "33");

list.add(u1);

list.add(u2);

list.add(u3);

for (int i = 0; i < list.size(); i++) {

System.out.println("list:" + list.get(i).toString());

}

User tmp = new User(4, 4, "44");

for (int i = 0; i < list.size(); i++) {

if (2 == list.get(i).getAge()) {

list.set(i, tmp);

}

}

System.out.println("=========================");

for (int i = 0; i < list.size(); i++) {

System.out.println("list:" + list.get(i).toString());

}

}

}

list:User [id=1, age=1, name=22]

list:User [id=2, age=2, name=22]

list:User [id=3, age=3, name=33]

=========================

list:User [id=1, age=1, name=22]

list:User [id=4, age=4, name=44]

list:User [id=3, age=3, name=33]