ArrayList按实体类排序

package com.yu.entity;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
//继承Comparable接口
public class SocketEntity implements Comparable<SocketEntity> {

	public static final int SEND_DATA = 1;	//发送数据
	public static final int GET_DATA = 2;	//获取数据
	public static final int DELETE_DATA = 3;	//删除数据
	public static final int DATA_BUFF = 1024;	//写入读取缓冲区
	
	public static final int FREE = 1;	//客户端空闲
	public static final int BUSY = 0;	//客户端忙碌
	
	private long frequency = 0L;	//使用频率
	
	private String name = null;		//客户端名称
	
	private Socket socket = null;	//客户端

	private int status = 0;		//服务状态 空闲FREE 忙碌BUSY
	
	OutputStream os = null;		//输出流	向客户端写数据
	
	InputStream is = null;		//输入流	向客户端读数据
	
	public SocketEntity(String name, Socket socket, int status) {
		this.name = name;
		this.socket = socket;
		this.status = status;
	}

	public String getName() {
		return name;
	}

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

	public Socket getSocket() {
		return socket;
	}

	public void setSocket(Socket socket) {
		this.socket = socket;
	}

	public int getStatus() {
		return status;
	}

	public void setStatus(int status) {
		this.status = status;
	}

	public long getFrequency() {
		return frequency;
	}

	public void setFrequency(long frequency) {
		this.frequency = frequency;
	}

	public void frequencyAddition(){
		long frequency = this.getFrequency();
		this.setFrequency(frequency++);
	}
	
	public OutputStream getOs() {
		try {
			return this.getSocket().getOutputStream();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;
	}

	public InputStream getIs() {
		try {
			return this.getSocket().getInputStream();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;
	}

	@Override
	public int compareTo(SocketEntity o) {
		
		if (this.getFrequency() == o.getFrequency()){
			return 0;	//等于
		}else if (this.getFrequency() > o.getFrequency()){
			return -1;	//小于
		}else{
			return 1;	//大于
		}
	}
	
}

 调用方法如下：

Collections.sort(socketEntity);