List集合中的对象按照某个字段去重实现

总感觉自己太菜，还在基础上摸爬滚打。

package com.huixin;

import java.util.*;

/**
* 根据对象属性字段给list集合去重
*
* @author Lance
* @date 2017/03/14
*/
public class ListQC {
public static void main(String[] args) {
List<User> userList = new ArrayList<User>();
User user1 = new User("张三", "001");
userList.add(user1);
User user2 = new User("李四", "001");
userList.add(user2);
User user3 = new User("王五", "002");
userList.add(user3);
for (User u : userList) {
System.out.println(u.getName());
}
System.out.println("去重后=======>");
List<User> userListNoDupAndSort = removeDuplicateUser(userList);
for (User u : userListNoDupAndSort) {
System.out.println(u.getName());
}
}
private static Arr
4000
ayList<User> removeDuplicateUser(List<User> users) {
Set<User> set = new TreeSet<User>(new Comparator<User>() {
@Override
public int compare(User o1, User o2) {
//字符串,则按照asicc码升序排列
return o1.getUserId().compareTo(o2.getUserId());
}
});
set.addAll(users);
return new ArrayList<User>(set);
}
}
class User {
private String name;
private String userId;

public User(String name, String userId) {
this.name = name;
this.userId = userId;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getUserId() {
return userId;
}

public void setUserId(String userId) {
this.userId = userId;
}
}

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效果：

张三
李四
王五
去重后=======>
张三
王五