Technology Architecture
- java11
- netty 4.1.79.Final
- redis communication protocol
Netty is used, so the project is a maven project
maven dependency (pom.xml)
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.79.Final</version>
</dependency>
Maven project packaging configuration (also in the pom.xml file)
<build>
<finalName>Redis_Cli</finalName><!-- 导出jar的名字 -->
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.0.0</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<!-- 指定启动类的全限定名-->
<mainClass>cn.xjt.NettyToRedis</mainClass>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
Use netty to connect to redis server and communicate all codes
package cn.xjt;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import java.net.InetSocketAddress;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
/**
* @author xujiangtao
* @version 1.0
* @description 使用netty框架利用redis协议操作redis
* @date 2022/7/31 17:03
*/
public class NettyToRedis {
/**
* redis规定协议
* *3 3：代表通过空格分割。有几个关键词及参数
* 换行
* $3 3:代表以下第一个关键词占几个字节（3个）
* 换行
* set
* 换行
* $4 4:同上
* 换行
* name
* $8 8:同上
* testname
*
*
* 所以普通的一条命令 set name testname 被按照以上固定协议则如下：
* *3
* $3
* set
* $4
* name
* $8
* testname
*/
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("请输入redis服务器地址（回车直接本地服务器：localhost）");
String hostname = scanner.nextLine();
if (hostname.equals("")){
hostname = "localhost";
}
int port;
System.out.println("请输入redis端口(回车直接端口默认：6379)");
while (true){
try {
String str = scanner.nextLine();
if (str.equals("")){
port = 6379;
}else {
port = Integer.parseInt(scanner.nextLine());
}
break;
}catch (NumberFormatException e){
System.out.println("请输入合法端口:"+e.getMessage());
}
}
NioEventLoopGroup boss = new NioEventLoopGroup();
Bootstrap bootstrap = new Bootstrap()
.group(boss)
.channel(NioSocketChannel.class)
.handler(new ChannelInitializer<NioSocketChannel>() {
@Override
protected void initChannel(NioSocketChannel channel){
Scanner sc = new Scanner(System.in);
channel.pipeline().addLast(new ChannelInboundHandlerAdapter(){
@Override
public void channelActive(ChannelHandlerContext ctx) {
System.out.println("连接成功，请输入redis的命令指令");
String commend = sc.nextLine();
sendCommend(ctx, commend.trim());
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {
ByteBuf byteBuf = (ByteBuf) msg;
String resp = byteBuf.toString(StandardCharsets.UTF_8);
// System.out.println("正常响应："+resp);
resp = resp.replace("\r\n","")
.replace("+", "")
.replace("$-1", "");
if (resp.contains("$")){
resp = resp.substring(2);
}
System.out.println(resp);
if (resp.equals("-NOAUTH Authentication required.")){
System.out.println("监测到连接该redis没有验证密码，请输入密码验证：");
String password = sc.nextLine();
String verifyCommend = "auth "+password;
sendCommend(ctx, verifyCommend);
}else {
String commend = sc.nextLine();
sendCommend(ctx, commend.trim());
}
}
});
}
});
try {
ChannelFuture connect = bootstrap.connect(new InetSocketAddress(hostname, port)).sync();
connect.channel().closeFuture().sync();
} catch (InterruptedException e) {
e.printStackTrace();
}finally {
boss.shutdownGracefully();
}
}
private static void sendCommend(ChannelHandlerContext ctx, String commend) {
// 空格+换行
final byte[] LINE = {
13,10};
if (commend.equals("q")){
System.out.println("正在退出程序...");
ctx.close();
}
List<String> words = Arrays.asList(commend.split(" "));
ByteBuf buffer = ctx.alloc().buffer();
buffer.writeBytes(("*" + words.size()).getBytes(StandardCharsets.UTF_8));
buffer.writeBytes(LINE);
for (String word : words) {
// 判断是不是中文汉字，如果是汉字，则每个汉字在utf-8 编码中占三个字节
if (checkChinese(word)){
// 所以每个汉字的字节数*3
buffer.writeBytes(("$" + word.length()*3).getBytes(StandardCharsets.UTF_8));
}else {
buffer.writeBytes(("$" + word.length()).getBytes(StandardCharsets.UTF_8));
}
buffer.writeBytes(LINE);
buffer.writeBytes(word.getBytes(StandardCharsets.UTF_8));
buffer.writeBytes(LINE);
}
ctx.writeAndFlush(buffer);
}
public static boolean checkChinese(String name)
{
int n;
for(int i = 0; i < name.length(); i++) {
n = name.charAt(i);
if(!(19968 <= n && n <40869)) {
return false;
}
}
return true;
}
}
How to use
1. You can build the project by yourself, pack the jar package, and execute the jar package operation (or start it directly in the idea)
2. Or directly download the packaged jar package (usejava -jarthe command to start it in the terminal)
jar package download address
redis_cli general client jar package download address
File download address (if the above jump is invalid, you can copy the link below to download)
http://xjtool.top:81/xjtfile/Redis_Cli.jar
The effect is as follows: (command q to exit the program)
Use medis (redis client tool) to verify. commands also take effect
epilogue
1. If you have any questions, you are welcome to guide, and at the same time, students are welcome to participate in technical exchanges. ❤️
2. If there are areas that need to be improved, you can also participate in the discussion.