目的
java 实战真实的例子，而不是侃侃而谈的理论。
netty 入门例子
maven
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.108.Final</version>
</dependency>
服务端
package com.github.houbb.netty.learn;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import java.nio.charset.StandardCharsets;
public class EchoServer {
public static void main(String[] args) throws Exception {
// 1. 创建线程组（Boss 负责连接，Worker 负责 I/O）
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
// 2. 配置服务端引导类
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) {
ch.pipeline().addLast(new EchoServerHandler());
}
});
// 3. 绑定端口并启动服务
ChannelFuture f = b.bind(8080).sync();
f.channel().closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
// 自定义处理器
class EchoServerHandler extends ChannelInboundHandlerAdapter {
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {
ByteBuf in = (ByteBuf) msg;
System.out.println("收到客户端消息: " + in.toString(StandardCharsets.UTF_8));
ctx.writeAndFlush(Unpooled.copiedBuffer("Hi Client!", StandardCharsets.UTF_8));
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
客户端
package com.github.houbb.netty.learn;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import java.nio.charset.StandardCharsets;
public class EchoClient {
public static void main(String[] args) throws Exception {
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(group)
.channel(NioSocketChannel.class)
.handler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) {
ch.pipeline().addLast(new EchoClientHandler());
}
});
// 连接服务端
ChannelFuture f = b.connect("127.0.0.1", 8080).sync();
f.channel().closeFuture().sync();
} finally {
group.shutdownGracefully();
}
}
}
// 自定义处理器
class EchoClientHandler extends ChannelInboundHandlerAdapter {
@Override
public void channelActive(ChannelHandlerContext ctx) {
ctx.writeAndFlush(Unpooled.copiedBuffer("Hello Server!", StandardCharsets.UTF_8));
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {
ByteBuf in = (ByteBuf) msg;
System.out.println("收到服务端响应: " + in.toString(StandardCharsets.UTF_8));
ctx.close();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}
测试
首先启动 EchoServer、然后启动 EchoClient
预期结果：
服务端输出：收到客户端消息: Hello Server!
客户端输出：收到服务端响应: Hi Client!
sofatbolt 例子
maven
<dependency>
<groupId>com.alipay.sofa</groupId>
<artifactId>bolt</artifactId>
<version>1.6.11</version>
</dependency>
服务端
package com.github.houbb.sofabolt.learn;
import com.alipay.remoting.BizContext;
import com.alipay.remoting.rpc.RpcServer;
import com.alipay.remoting.rpc.protocol.SyncUserProcessor;
public class SofaBoltServer {
public static void main(String[] args) {
// 1. 创建 RPC 服务端（自动管理线程池）
RpcServer rpcServer = new RpcServer(12200);
// 2. 注册用户处理器（处理字符串消息）
rpcServer.registerUserProcessor(new SyncUserProcessor<String>() {
@Override
public Object handleRequest(BizContext bizContext, String s) throws Exception {
System.out.println("收到客户端消息: " + s);
return "Hi Client!"; // 直接返回响应
}
@Override
public String interest() {
return String.class.getName(); // 声明处理的消息类型
}
});
// 3. 启动服务
rpcServer.start();
System.out.println("Server started on port 12200");
}
}
客户端
package com.github.houbb.sofabolt.learn;
import com.alipay.remoting.rpc.RpcClient;
public class SofaBoltClient {
public static void main(String[] args) {
// 1. 创建 RPC 客户端（自动管理连接池）
RpcClient rpcClient = new RpcClient();
rpcClient.init();
try {
// 2. 同步调用（指定地址、请求体、超时时间）
String response = (String) rpcClient.invokeSync(
"127.0.0.1:12200",
"Hello Server!",
3000 // 超时 3 秒
);
System.out.println("收到服务端响应: " + response);
} catch (Exception e) {
e.printStackTrace();
} finally {
rpcClient.shutdown();
}
}
}
测试验证
服务端启动，客户端启动。
服务端日志：
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Sofa-Middleware-Log:WARN [com.alipay.remoting] No log util is usable, Default app logger will be used.
Server started on port 12200
Sofa-Middleware-Log:WARN [sofa-common-tools] No log util is usable, Default app logger will be used.
三月 26, 2025 8:09:25 下午 com.caucho.hessian.io.AbstractStringBuilderDeserializer <clinit>
警告: coder field not found or not accessible, will skip coder check, error is coder
Sofa-Middleware-Log:WARN [com.alipay.sofa.hessian] No log util is usable, Default app logger will be used.
收到客户端消息: Hello Server!
客户端日志
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Sofa-Middleware-Log:WARN [com.alipay.remoting] No log util is usable, Default app logger will be used.
三月 26, 2025 8:09:24 下午 com.caucho.hessian.io.AbstractStringBuilderDeserializer <clinit>
警告: coder field not found or not accessible, will skip coder check, error is coder
Sofa-Middleware-Log:WARN [com.alipay.sofa.hessian] No log util is usable, Default app logger will be used.
收到服务端响应: Hi Client!
参考资料
https://www.sofastack.tech/projects/sofa-bolt/sofa-bolt-handbook/
