java | netty 向 redis 传递数据

通过自己编写的 netty 客户端向 redis 写入数据。

redis 的 set key value，其协议是这样的。

set key value
*3 「表明元素有几个」
$3 「长度 3 个字节为 set」
set
$4 「假设 key = name，则这是 4 个字节」
name
$3 「假设 value 为 aaa，则是 3 个字节」
aaa

ps: 每一行都需要一个 回车 + 换行进行分割

package com.redisc;

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.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.nio.charset.Charset;
import java.util.Random;

public class Client {
    static final Logger log = LoggerFactory.getLogger(Client.class);

public static void main(String[] args) throws IOException, InterruptedException {
        send();
    }

public static void send() {
        final byte[] LINE = {13, 10};
        NioEventLoopGroup worker = new NioEventLoopGroup();

try {
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.channel(NioSocketChannel.class);
            bootstrap.group(worker);
            bootstrap.handler(new ChannelInitializer<SocketChannel>() {
                @Override
                protected void initChannel(SocketChannel socketChannel) throws Exception {
                    socketChannel.pipeline().addLast(new LoggingHandler(LogLevel.DEBUG));
                    socketChannel.pipeline().addLast(new ChannelInboundHandlerAdapter() {
                        @Override
                        // 会在连接 channel 建立成功后，触发 active 事件
                        public void channelActive(ChannelHandlerContext ctx) throws Exception {
                            ByteBuf buf = ctx.alloc().buffer();
                            buf.writeBytes("*3".getBytes());
                            buf.writeBytes(LINE);
                            buf.writeBytes("$3".getBytes());
                            buf.writeBytes(LINE);
                            buf.writeBytes("set".getBytes());
                            buf.writeBytes(LINE);
                            buf.writeBytes("$4".getBytes());
                            buf.writeBytes(LINE);
                            buf.writeBytes("name".getBytes());
                            buf.writeBytes(LINE);
                            buf.writeBytes("$3".getBytes());
                            buf.writeBytes(LINE);
                            buf.writeBytes("aaa".getBytes());
                            buf.writeBytes(LINE);
                            ctx.writeAndFlush(buf);
                        }

@Override
                        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                        	// 返回数据
                            ByteBuf byteBuf = (ByteBuf)msg;
                            System.out.println(byteBuf.toString(Charset.defaultCharset()));
                        }
                    });
                }
            });
            ChannelFuture channelFuture = bootstrap.connect("127.0.0.1", 6379);
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            log.error("error", e);
        } finally {
            worker.shutdownGracefully();
        }
    }
}

20:26:56.315 [nioEventLoopGroup-2-1] DEBUG io.netty.util.ResourceLeakDetectorFactory - Loaded default ResourceLeakDetector: io.netty.util.ResourceLeakDetector@1f26c33b
20:26:56.321 [nioEventLoopGroup-2-1] DEBUG io.netty.handler.logging.LoggingHandler - [id: 0x24ec6db4, L:/127.0.0.1:57820 - R:/127.0.0.1:6379] WRITE: 32B
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 2a 33 0d 0a 24 33 0d 0a 73 65 74 0d 0a 24 34 0d |*3..$3..set..$4.|
|00000010| 0a 6e 61 6d 65 0d 0a 24 33 0d 0a 61 61 61 0d 0a |.name..$3..aaa..|
+--------+-------------------------------------------------+----------------+
20:26:56.322 [nioEventLoopGroup-2-1] DEBUG io.netty.handler.logging.LoggingHandler - [id: 0x24ec6db4, L:/127.0.0.1:57820 - R:/127.0.0.1:6379] FLUSH
20:26:56.328 [nioEventLoopGroup-2-1] DEBUG io.netty.handler.logging.LoggingHandler - [id: 0x24ec6db4, L:/127.0.0.1:57820 - R:/127.0.0.1:6379] READ: 5B
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 2b 4f 4b 0d 0a                                  |+OK..           |
+--------+-------------------------------------------------+----------------+
+OK