基于Springboot+Netty实现rpc的方法 附demo

基于Springboot+Netty实现rpc的方法 附demo

今天翻看了一下Netty相关的知识点，正好练练手，简单捣鼓了这个demo;这里简单梳理一下；

前提知识点：

Springboot、 Netty、动态代理(反射)、反射

项目整体结构如下：

1.在父项目中引入相关依赖；

org.springframework.boot

spring-boot-starter-web

2.3.2.RELEASE

io.netty

netty-all

4.1.48.Final

com.alibaba

fastjson

1.2.58

org.slf4j

slf4j-log4j12

2.0.0-alpha1

2.服务提供模块整体结构如下：

这里重点关注一下 RequestModel  和 ResponseModel 两个消息体类，

@Data

@AllArgsConstructor

public class RequestModel {

private String requestId;

private String serviceName;

private String methodName;

private Class[] paramTypes;

private Object[] paramValues;

}

@Data

@AllArgsConstructor

public class ResponseModel {

private String responseId;

private String serviceName;

private String methodName;

private String code;

private String data;

}

用于服务端和客户端的数据传输；再者就是关注 ServerChannelInboundHandler 中的 channelRead0() 报文解码处理；

@Override

protected void channelRead0(ChannelHandlerContext ctx, String msg) {

StringBuilder sb = null;

RequestModel result = null;

try {

// 报文解析处理

sb = new StringBuilder();

result = JSON.parseObject(msg, RequestModel.class);

requestId = result.getRequestId();

String serviceName = result.getServiceName();

String methodName = result.getMethodName();

Class[] paramType = result.getParamTypes();

Object[] paramValue = result.getParamValues();

System.out.println(serviceName + " " + methodName);

String substring = serviceName.substring(serviceName.lastIndexOf(".") + 1);

String s = substring.substring(0, 1).toLowerCase() + substring.substring(1);

Object serviceObject = applicationContext.getBean(s);

Method method = Class.forName(serviceName).getMethod(methodName, paramType);

Object returnValue = method.invoke(serviceObject, paramValue);

ResponseModel responseModel = new ResponseModel(requestId,serviceName,methodName,"200",JSON.toJSONString(returnValue));

sb.append(JSON.toJSONString(responseModel));

sb.append("\n");

System.out.println(sb.toString());

ctx.writeAndFlush(sb);

} catch (Exception e) {

ResponseModel responseModel = new ResponseModel(requestId,"","","500",e.getMessage());

String errorCode = JSON.toJSONString(responseModel)+"\n";

log.error(errorCode);

ctx.writeAndFlush(errorCode);

log.error("报文解析失败: " + e.getMessage());

}

}

客户端的模块代码如下；

这里重点关注的是 ClientHandler 类中 channelRead0() 方法的处理

@Override

protected void channelRead0(ChannelHandlerContext ctx, String msg) {

System.out.println("收到服务端消息: " + msg);

ResponseModel responseModel = JSON.parseObject(msg,ResponseModel.class);

String responseId = responseModel.getResponseId();

Promise promise = LocalPromise.promiseMap.remove(responseId);

if(promise != null){

String code = responseModel.getCode();

if(code.equals("200")){

promise.setSuccess(responseModel.getData());

}else{

promise.setFailure(new RuntimeException(responseModel.getData()));

}

}

}

和 AppStart 类中获取获取服务的处理；

private T getProxyService(Class serviceClass) {

Object service = Prohttp://xy.newProxyInstance(serviceClass.getClassLoader(), new Class[]{serviceClass}, new InvocationHandler() {

@Override

public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

Channel channel = NettyClient.getChannel(host, port);

RequestModel requestModel = new RequestModel("100001", method.getDeclaringClass().getName(), method.getName(), method.getParameterTypes(), args);

channel.writeAndFlush(JSON.toJSONString(requestModel) + "\n");

Promise promise = new DefaultPromise(channel.eventLoop());

LocalPromise.promiseMap.put(requestModel.getRequestId(), promise);

System.out.println(LocalPromise.promiseMap+">>>>>>>>>>>>");

promise.await();

if (promise.isSuccess()) {

Class> returnType = method.getReturnType();

return JSON.tojavaObject(JSON.parseObject(promise.getNow()+""),returnType);

} else {

System.out.println(promise.cause());

return promise.cause();

}

}

});

return (T) service;

}

测试结果：

总结： 这个demo相对比较简单，但对于理解rpc 远程调用有一定帮助，最后分享一下这个代码地址：

nettydemo: netty springboot rpc远程调用demo

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