ArrayList数组对象排序

POJO

package com.test.comparator;

public class User
{
	private String name;
	private String age;
	 
	 public User(String name,String age){
	  this.name=name;
	  this.age=age;
	 }
	 public String getAge() {
	  return age;
	 }
	 public void setAge(String age) {
	  this.age = age;
	 }
	 public String getName() {
	  return name;
	 }
	 public void setName(String name) {
	  this.name = name;
	 } 
	}

java中Comparator的用法
在java中，如果要对集合对象或数组对象进行排序，需要实现Comparator接口以达到我们想要的目标。

package com.test.comparator;

import java.util.Comparator;


public class ComparatorUser implements Comparator
{

	public int compare(Object o1, Object o2)
	{
		User user0=(User)o1;
	    User user1=(User)o2;
	    
	    //首先比较年龄，如果年龄相同，则比较姓名
	    int flag=user0.getAge().compareTo(user1.getAge());
	    
	    if(flag==0){
	     return user0.getName().compareTo(user1.getName());
	    }else{
	     return flag;
	    } 
	}

}

测试类

package com.test.comparator;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

//测试类
public class SortTest
{
	 public static void main(String[] args){
		  List userlist=new ArrayList();
		  userlist.add(new User("dd","4"));
		  userlist.add(new User("aa","1"));
		  userlist.add(new User("ee","5"));
		  userlist.add(new User("bb","2"));  
		  userlist.add(new User("ff","5"));
		  userlist.add(new User("cc","3"));
		  userlist.add(new User("gg","6"));
		  
		  ComparatorUser comparator=new ComparatorUser();
		  Collections.sort(userlist, comparator);
		   
		  for (int i=0;i<userlist.size();i++){
		   User user_temp=(User)userlist.get(i);
		      System.out.println(user_temp.getAge()+","+user_temp.getName()); 
		  }
		  
		 }
}