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；
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <version>2.3.2.RELEASE</version> </dependency> <dependency> <groupId>io.netty</groupId> <artifactId>netty-all</artifactId> <version>4.1.48.Final</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.58</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>2.0.0-alpha1</version> </dependency> |
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，
|
1 2 3 4 5 6 7 8 9 10 11 |
@Data @AllArgsConstructor public class RequestModel {
private String requestId; private String serviceName; private String methodName; private Class[] paramTypes; private Object[] paramValues;
} |
|
1 2 3 4 5 6 7 8 9 |
@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；
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 |
@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
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
@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；
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 |
private <T> T getProxyService(Class<T> serviceClass) { Object service = Proxy.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
https://gitee.com/lizhiyunfengxiang/nettydemo
