List自定义排序

List自定义排序我习惯根据Collections.sort重载方法来实现，下面我只实现自己习惯方式。还有一种就是实现Comparable接口。

挺简单的，直接上代码吧。

package com.sort;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
/**
 * list自定义排序
 * @author root
 *
 */
public class ListSort {
	@SuppressWarnings("unchecked")
	public static void main(String[] args) {
		User user1 = new User();
		user1.setName("a");
		user1.setAge(19);
		user1.setOrder(10);
		User user2 = new User();
		user2.setName("b");
		user2.setAge(20);
		user2.setOrder(2);
		User user3 = new User();
		user3.setName("c");
		user3.setAge(20);
		user3.setOrder(1);
		List<User> list = new ArrayList<User>();
		list.add(user1);
		list.add(user2);
		list.add(user3);
		/*自定义按照age排序
    	Collections.sort(list,new Comparator(){
			@Override
			public int compare(Object o1, Object o2) {
				 User u1 = (User)o1;
				 User u2 = (User)o2;
				 return u1.getAge().compareTo(u2.getAge());
			}
		 });*/
		//如果age相同，再按照order排序
		Collections.sort(list,new Comparator(){
			@Override
			public int compare(Object o1, Object o2) {
				 User u1 = (User)o1;
				 User u2 = (User)o2;
				 int i = u1.getAge().compareTo(u2.getAge());
				 if(i == 0){
					 return u1.getOrder().compareTo(u2.getOrder());
				 }
				 return i;
			}
		 });
	    for(User user : list){
	    	System.out.println("Name:"+user.getName()+"  Age:"+user.getAge()+"  Order:"+user.getOrder());
	    }
	}
}

　User类：

package com.sort;

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

}