Netty与Spring Boot的整合
最近有朋友向我询问一些Netty与SpringBoot整合的相关问题,这里,我就总结了一下基本整合流程,也就是说,这篇文章 ,默认大家是对netty与Spring,SpringMVC的整合是没有什么问题的。现在,就进入正题吧。
Server端:
总的来说,服务端还是比较简单的,自己一共写了三个核心类。分别是
- NettyServerListener:服务启动监听器
- ServerChannelHandlerAdapter:通道适配器,主要用于多线程共享
- RequestDispatcher:请求分排器
下面开始集成过程:
-
在pom.xml中添加以下依赖
<dependency> <groupId>io.netty</groupId> <artifactId>netty-all</artifactId> <version>5.0.0.Alpha2</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-configuration-processor</artifactId> <optional>true</optional> </dependency>
-
让SpringBoot的启动类实现CommandLineRunner接口并重写run方法,比如我的启动类是CloudApplication.java
@SpringBootApplication public class CloudApplication implements CommandLineRunner { public static void main(String[] args) { SpringApplication.run(CloudApplication.class, args); } @Override public void run(String... strings) { } }
-
创建类NettyServerListener.java
// 读取yml的一个配置类 import com.edu.hart.modules.constant.NettyConfig; // Netty连接信息配置类 import com.edu.hart.modules.constant.NettyConstant; // import com.edu.hart.rpc.util.ObjectCodec; import io.netty.bootstrap.ServerBootstrap; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelInitializer; import io.netty.channel.ChannelPipeline; import io.netty.channel.EventLoopGroup; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.SocketChannel; import io.netty.channel.socket.nio.NioServerSocketChannel; import io.netty.handler.codec.LengthFieldBasedFrameDecoder; import io.netty.handler.codec.LengthFieldPrepender; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import javax.annotation.PreDestroy; import javax.annotation.Resource; /** * 服务启动监听器 * * @author 叶云轩 */ @Component public class NettyServerListener { /** * NettyServerListener 日志输出器 * * @author 叶云轩 create by 2017/10/31 18:05 */ private static final Logger LOGGER = LoggerFactory.getLogger(NettyServerListener.class); /** * 创建bootstrap */ ServerBootstrap serverBootstrap = new ServerBootstrap(); /** * BOSS */ EventLoopGroup boss = new NioEventLoopGroup(); /** * Worker */ EventLoopGroup work = new NioEventLoopGroup(); /** * 通道适配器 */ @Resource private ServerChannelHandlerAdapter channelHandlerAdapter; /** * NETT服务器配置类 */ @Resource private NettyConfig nettyConfig; /** * 关闭服务器方法 */ @PreDestroy public void close() { LOGGER.info("关闭服务器...."); //优雅退出 boss.shutdownGracefully(); work.shutdownGracefully(); } /** * 开启及服务线程 */ public void start() { // 从配置文件中(application.yml)获取服务端监听端口号 int port = nettyConfig.getPort(); serverBootstrap.group(boss, work) .channel(NioServerSocketChannel.class) .option(ChannelOption.SO_BACKLOG, 100) .handler(new LoggingHandler(LogLevel.INFO)); try { //设置事件处理 serverBootstrap.childHandler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) throws Exception { ChannelPipeline pipeline = ch.pipeline(); pipeline.addLast(new LengthFieldBasedFrameDecoder(nettyConfig.getMaxFrameLength() , 0, 2, 0, 2)); pipeline.addLast(new LengthFieldPrepender(2)); pipeline.addLast(new ObjectCodec()); pipeline.addLast(channelHandlerAdapter); } }); LOGGER.info("netty服务器在[{}]端口启动监听", port); ChannelFuture f = serverBootstrap.bind(port).sync(); f.channel().closeFuture().sync(); } catch (InterruptedException e) { LOGGER.info("[出现异常] 释放资源"); boss.shutdownGracefully(); work.shutdownGracefully(); } } }
-
创建类ServerChannelHandlerAdapter.java - 通道适配器
// 记录调用方法的元信息的类 import com.edu.hart.rpc.entity.MethodInvokeMeta; import io.netty.channel.ChannelHandler.Sharable; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import javax.annotation.Resource; /** * 多线程共享 */ @Component @Sharable public class ServerChannelHandlerAdapter extends ChannelHandlerAdapter { /** * 日志处理 */ private Logger logger = LoggerFactory.getLogger(ServerChannelHandlerAdapter.class); /** * 注入请求分排器 */ @Resource private RequestDispatcher dispatcher; @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { cause.printStackTrace(); ctx.close(); } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) { MethodInvokeMeta invokeMeta = (MethodInvokeMeta) msg; // 屏蔽toString()方法 if (invokeMeta.getMethodName().endsWith("toString()") && !"class java.lang.String".equals(invokeMeta.getReturnType().toString())) logger.info("客户端传入参数 :{},返回值:{}", invokeMeta.getArgs(), invokeMeta.getReturnType()); dispatcher.dispatcher(ctx, invokeMeta); } }
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RequestDispatcher.java
// 封装的返回信息枚举类 import com.edu.hart.modules.communicate.ResponseCodeEnum; // 封装的返回信息实体类 import com.edu.hart.modules.communicate.ResponseResult; // 封装的连接常量类 import com.edu.hart.modules.constant.NettyConstant; // 记录元方法信息的实体类 import com.edu.hart.rpc.entity.MethodInvokeMeta; // 对于返回值为空的一个处理 import com.edu.hart.rpc.entity.NullWritable; // 封装的返回信息实体工具类 import com.edu.hart.rpc.util.ResponseResultUtil; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandlerContext; import org.springframework.beans.BeansException; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import org.springframework.stereotype.Component; import java.lang.reflect.Method; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; /** * 请求分排器 */ @Component public class RequestDispatcher implements ApplicationContextAware { private ExecutorService executorService = Executors.newFixedThreadPool(NettyConstant.getMaxThreads()); private ApplicationContext app; /** * 发送 * * @param ctx * @param invokeMeta */ public void dispatcher(final ChannelHandlerContext ctx, final MethodInvokeMeta invokeMeta) { executorService.submit(() -> { ChannelFuture f = null; try { Class<?> interfaceClass = invokeMeta.getInterfaceClass(); String name = invokeMeta.getMethodName(); Object[] args = invokeMeta.getArgs(); Class<?>[] parameterTypes = invokeMeta.getParameterTypes(); Object targetObject = app.getBean(interfaceClass); Method method = targetObject.getClass().getMethod(name, parameterTypes); Object obj = method.invoke(targetObject, args); if (obj == null) { f = ctx.writeAndFlush(NullWritable.nullWritable()); } else { f = ctx.writeAndFlush(obj); } f.addListener(ChannelFutureListener.CLOSE); } catch (Exception e) { ResponseResult error = ResponseResultUtil.error(ResponseCodeEnum.SERVER_ERROR); f = ctx.writeAndFlush(error); } finally { f.addListener(ChannelFutureListener.CLOSE); } }); } /** * 加载当前application.xml * * @param ctx * @throws BeansException */ public void setApplicationContext(ApplicationContext ctx) throws BeansException { this.app = ctx; } }
-
application.yml文件中对于netty的一个配置
netty: port: 11111
-
NettyConfig.java
import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.stereotype.Component; /** * 读取yml配置文件中的信息 * Created by 叶云轩 on 2017/10/31 - 18:38 * Concat tdg_yyx@foxmail.com */ @Component @ConfigurationProperties(prefix = "netty") public class NettyConfig { private int port; public int getPort() { return port; } public void setPort(int port) { this.port = port; } }
-
NettyConstanct.java
import org.springframework.stereotype.Component; /** * Netty服务器常量 * Created by 叶云轩 on 2017/10/31 - 17:47 * Concat tdg_yyx@foxmail.com */ @Component public class NettyConstant { /** * 最大线程量 */ private static final int MAX_THREADS = 1024; /** * 数据包最大长度 */ private static final int MAX_FRAME_LENGTH = 65535; public static int getMaxFrameLength() { return MAX_FRAME_LENGTH; } public static int getMaxThreads() { return MAX_THREADS; } }
至此,netty服务端算是与SpringBoot整合成功。那么看一下启动情况吧。
Client端:
Client我感觉要比Server端要麻烦一点。这里还是先给出核心类吧。
- NettyClient : netty客户端
- ClientChannelHandlerAdapter : 客户端通道适配器
- CustomChannelInitalizer:自定义通道初始化工具
- RPCProxyFactoryBean:RPC通信代理工厂
在Client端里。SpringBoot的启动类要继承SpringBootServletInitializer这个类,并覆盖SpringApplicationBuilder方法
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;
@SpringBootApplication
public class OaApplication extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication.run(OaApplication.class, args);
}
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
return builder.sources(OaApplication.class);
}
}
-
NettyClient.java
// 记录元方法信息的实体类 import com.edu.hart.rpc.entity.MethodInvokeMeta; import io.netty.bootstrap.Bootstrap; import io.netty.channel.ChannelFuture; import io.netty.channel.EventLoopGroup; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.nio.NioSocketChannel; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.management.MBeanServer; /** * 客户端发送类 * Created by 叶云轩 on 2017/6/16-16:58 * Concat tdg_yyx@foxmail.com */ public class NettyClient { private Logger logger = LoggerFactory.getLogger(MBeanServer.class); private Bootstrap bootstrap; private EventLoopGroup worker; private int port; private String url; private int MAX_RETRY_TIMES = 10; public NettyClient(String url, int port) { this.url = url; this.port = port; bootstrap = new Bootstrap(); worker = new NioEventLoopGroup(); bootstrap.group(worker); bootstrap.channel(NioSocketChannel.class); } public void close() { logger.info("关闭资源"); worker.shutdownGracefully(); } public Object remoteCall(final MethodInvokeMeta cmd, int retry) { try { CustomChannelInitializerClient customChannelInitializer = new CustomChannelInitializerClient(cmd); bootstrap.handler(customChannelInitializer); ChannelFuture sync = bootstrap.connect(url, port).sync(); sync.channel().closeFuture().sync(); Object response = customChannelInitializer.getResponse(); return response; } catch (InterruptedException e) { retry++; if (retry > MAX_RETRY_TIMES) { throw new RuntimeException("调用Wrong"); } else { try { Thread.sleep(100); } catch (InterruptedException e1) { e1.printStackTrace(); } logger.info("第{}次尝试....失败", retry); return remoteCall(cmd, retry); } } } }
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ClientChannelHandlerAdapter.java
import com.edu.hart.rpc.entity.MethodInvokeMeta; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Created by 叶云轩 on 2017/6/16-17:03 * Concat tdg_yyx@foxmail.com */ public class ClientChannelHandlerAdapter extends ChannelHandlerAdapter { private Logger logger = LoggerFactory.getLogger(ClientChannelHandlerAdapter.class); private MethodInvokeMeta methodInvokeMeta; private CustomChannelInitializerClient channelInitializerClient; public ClientChannelHandlerAdapter(MethodInvokeMeta methodInvokeMeta, CustomChannelInitializerClient channelInitializerClient) { this.methodInvokeMeta = methodInvokeMeta; this.channelInitializerClient = channelInitializerClient; } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { logger.info("客户端出异常了,异常信息:{}", cause.getMessage()); cause.printStackTrace(); ctx.close(); } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { if (methodInvokeMeta.getMethodName().endsWith("toString") && !"class java.lang.String".equals(methodInvokeMeta.getReturnType().toString())) logger.info("客户端发送信息参数:{},信息返回值类型:{}", methodInvokeMeta.getArgs(), methodInvokeMeta.getReturnType()); ctx.writeAndFlush(methodInvokeMeta); } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { channelInitializerClient.setResponse(msg); } }
-
CustomChannelInitializerClient.java
import com.edu.hart.rpc.entity.MethodInvokeMeta; import com.edu.hart.rpc.entity.NullWritable; import com.edu.hart.rpc.util.ObjectCodec; import io.netty.channel.ChannelInitializer; import io.netty.channel.ChannelPipeline; import io.netty.channel.socket.SocketChannel; import io.netty.handler.codec.LengthFieldBasedFrameDecoder; import io.netty.handler.codec.LengthFieldPrepender; import org.slf4j.Logger; import org.slf4j.LoggerFactory;
/**
- Created by 叶云轩 on 2017/6/16-15:01
- Concat tdg_yyx@foxmail.com
*/
public class CustomChannelInitializerClient extends ChannelInitializer{
private Logger logger = LoggerFactory.getLogger(CustomChannelInitializerClient.class);
private MethodInvokeMeta methodInvokeMeta;
private Object response;
public CustomChannelInitializerClient(MethodInvokeMeta methodInvokeMeta) {
if (!"toString".equals(methodInvokeMeta.getMethodName())) {
logger.info("[CustomChannelInitializerClient] 调用方法名:{},入参:{},参数类型:{},返回值类型{}"
, methodInvokeMeta.getMethodName()
, methodInvokeMeta.getArgs()
, methodInvokeMeta.getParameterTypes()
, methodInvokeMeta.getReturnType());
}
this.methodInvokeMeta = methodInvokeMeta;
}
public Object getResponse() {
if (response instanceof NullWritable) {
return null;
}
return response;
}
public void setResponse(Object response) {
this.response = response;
}
@Override
protected void initChannel(SocketChannel ch) {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast(new LengthFieldPrepender(2));
pipeline.addLast(new LengthFieldBasedFrameDecoder(1024 * 1024, 0, 2, 0, 2));
pipeline.addLast(new ObjectCodec());
pipeline.addLast(new ClientChannelHandlerAdapter(methodInvokeMeta, this));
}
}
4. RPCProxyFactoryBean.java
import com.edu.hart.rpc.entity.MethodInvokeMeta;
import com.edu.hart.rpc.util.WrapMethodUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.config.AbstractFactoryBean;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/**
* Created by 叶云轩 on 2017/6/16-17:16
* Concat tdg_yyx@foxmail.com
*/
public class RPCProxyFactoryBean extends AbstractFactoryBean