RESP协议是Redis客户端和服务端之间的通讯协议,官方文档:https://redis.io/topics/protocol
客户端与服务端是通过tcp连接通信的,发送的数据需要遵循RESP协议:
*代表数组(数据报中字符串个数)
$代表字符串长度
+代表简单字符串
-错误信息
:整型数字
每段数据需要以"\r\n"结尾
例如:set key "value"编码如下
*3\r\n$3\r\nset\r\n$3\r\nkey\r\n$5\r\nvalue\r\n
客户端
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
/**
* @author Administrator
* @description redis客户端实现
* @date 2020/1/8
*/
public class RedisClient {
private Socket socket;
private OutputStream writer;
private InputStream reader;
public RedisClient(String host,int port) throws IOException {
//与Redis服务端的Socket连接
socket = new Socket(host,port);
writer = socket.getOutputStream();
reader = socket.getInputStream();
}
//密码验证 *2$5\r\nauth\r\n$5\r\n12345
public String auth(String password) throws IOException {
StringBuffer conmmand = new StringBuffer();
//*2:表示有两个字符串
conmmand.append("*2").append("\r\n");
//$4:表示auth长度为4
conmmand.append("$4").append("\r\n");
conmmand.append("auth").append("\r\n");
conmmand.append("$").append(password.getBytes().length).append("\r\n");
conmmand.append(password).append("\r\n");
return exceConmmand(conmmand);
}
//set命令
public String set(String key,String value) throws IOException {
StringBuffer conmmand = new StringBuffer();
conmmand.append("*3").append("\r\n");
conmmand.append("$3").append("\r\n");
conmmand.append("SET").append("\r\n");
conmmand.append("$").append(key.getBytes().length).append("\r\n");
conmmand.append(key).append("\r\n");
conmmand.append("$").append(value.getBytes().length).append("\r\n");
conmmand.append(value).append("\r\n");
return exceConmmand(conmmand);
}
//get key
public String get(String key) throws IOException{
StringBuffer conmmand = new StringBuffer();
conmmand.append("*2").append("\r\n");
conmmand.append("$3").append("\r\n");
conmmand.append("get").append("\r\n");
conmmand.append("$").append(key.getBytes().length).append("\r\n");
conmmand.append(key).append("\r\n");
return exceConmmand(conmmand);
}
//写命令
public String exceConmmand(StringBuffer conmmand) throws IOException {
writer.write(conmmand.toString().getBytes());
byte[] result = new byte[1024];
reader.read(result);
return new String(result);
}
}
测试
public class ClientTest {
public static void main(String[] args) {
try {
RedisClient client = new RedisClient("127.0.0.1",6379);
String result = client.auth("12345");
String set = client.set("redis","test");
String get = client.get("redis");
System.out.println(result+"-----"+set+"----"+get);
} catch (IOException e) {
e.printStackTrace();
}
}
}