redis 模拟jedis 操作string类型数据

一.思路分析

redis数据传输遵循resp协议,只需要按照resp协议并通过socket传递数据到redis服务器即可

resp数据格式:

 

二.具体实现

package com.ahd.jedis;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

/***
 * 模拟jedis对redis进行操作
 */
public class MyJedis {
    private Socket socket;

    public MyJedis(String url,Integer port) throws IOException {
        socket=new Socket(url,port);
    }

    public static void main(String[] args) throws IOException {
        MyJedis myJedis=new MyJedis("127.0.0.1",6379);

        //myJedis.set("sex","sdf");
        //myJedis.get("sex");
        myJedis.del("sex");
    }

    /***
     * 模拟set string类型
     * @param key
     * @param value
     */
    public void set(String key,String value) throws IOException {
        StringBuffer stringBuffer=new StringBuffer();
        //getBytes 是因为key和value可能是中文，直接获取长度会出错
        stringBuffer.append("*3"+"
")
                .append("$3"+"
").append("SET"+"
")
                .append("$"+key.getBytes().length+"
").append(key+"
")
                .append("$"+value.getBytes().length+"
").append(value+"
");
        OutputStream outputStream = socket.getOutputStream();

        System.out.println(stringBuffer);
        outputStream.write(stringBuffer.toString().getBytes());

    }

    /***
     * 模拟get String
     * @param key
     * @return
     */
    public String get(String key) throws IOException {
        StringBuffer stringBuffer=new StringBuffer();
        //getBytes 是因为key和value可能是中文，直接获取长度会出错
        stringBuffer.append("*2"+"
")
                .append("$3"+"
").append("get"+"
")
                .append("$"+key.getBytes().length+"
").append(key+"
");
        //1. 将命令传递到redis
        OutputStream outputStream = socket.getOutputStream();
        outputStream.write(stringBuffer.toString().getBytes());

        //2. 接收redis的响应结果
        InputStream inputStream = socket.getInputStream();
        byte[] b=new byte[2048];
        inputStream.read(b);

        return new String(b);
    }

    /***
     * 指定key 删除
     * @param key
     * @return
     * @throws IOException
     */
    public void del(String key) throws IOException {
        StringBuffer stringBuffer=new StringBuffer();
        //getBytes 是因为key和value可能是中文，直接获取长度会出错
        stringBuffer.append("*2"+"
")
                .append("$3"+"
").append("del"+"
")
                .append("$"+key.getBytes().length+"
").append(key+"
");
        //1. 将命令传递到redis
        OutputStream outputStream = socket.getOutputStream();
        outputStream.write(stringBuffer.toString().getBytes());
        outputStream.flush();
    }

}

 

三.运行结果