[Java] List集合多个复杂字段判断去重的案例

package com.test;
import java.math.bigdecimal;
import java.util.arraylist;
import java.util.arrays;
import java.util.list;
import org.apache.commons.collections.collectionutils;
public class testcollection {
 //去重复之前集合
 private static list<user> list = arrays.aslist(
  new user("张三", bigdecimal.valueof(35.6), 18),
  new user("李四", bigdecimal.valueof(85), 30),
  new user("赵六", bigdecimal.valueof(66.55), 25),
  new user("赵六", bigdecimal.valueof(66.55), 25),
  new user("张三", bigdecimal.valueof(35.6), 18));
 public static void main(string[] args) {
 //排除重复
 getnorepeatlist(list);
 
 }
 /**
 * 去除list内复杂字段重复对象
 * @param oldlist
 * @return
 */
 private static list<user> getnorepeatlist(list<user> oldlist){
 list<user> list = new arraylist<>();
 if(collectionutils.isnotempty(oldlist)){
  for (user user : oldlist) {
  //list去重复，内部重写equals
  if(!list.contains(user)){
   list.add(user);
  }
  }
 }
 //输出新集合
 system.out.println("去除重复后新集合：");
 if(collectionutils.isnotempty(list)){
  for (user user : list) {
  system.out.println(user.tostring());
  }
 }
 return list; 
 } 
 static class user{
 private string username; //姓名
 private bigdecimal score;//分数
 private integer age;
 public string getusername() {
  return username;
 }
 public void setusername(string username) {
  this.username = username;
 }
 public bigdecimal getscore() {
  return score;
 }
 public void setscore(bigdecimal score) {
  this.score = score;
 }
 public integer getage() {
  return age;
 }
 public void setage(integer age) {
  this.age = age;
 }
 public user(string username, bigdecimal score, integer age) {
  super();
  this.username = username;
  this.score = score;
  this.age = age;
 }
 public user() {
  // todo auto-generated constructor stub
 }
 @override
 public string tostring() {
  // todo auto-generated method stub
  return "姓名："+ this.username + "，年龄：" + this.age + "，分数：" + this.score;
 }
 /**
  * 重写equals,用于比较对象属性是否包含
  */
 public boolean equals(object obj) { 
   if (obj == null) { 
     return false; 
   } 
   if (this == obj) { 
     return true; 
   } 
   user user = (user) obj; 
   //多重逻辑处理，去除年龄、姓名相同的记录
   if (this.getage() .compareto(user.getage())==0
    && this.getusername().equals(user.getusername())
    && this.getscore().compareto(user.getscore())==0) { 
     return true; 
   } 
   return false; 
   } 
 }
}

去除重复后新集合：
姓名：张三，年龄：18，分数：35.6
姓名：李四，年龄：30，分数：85
姓名：赵六，年龄：25，分数：66.55