手写RPC
服务端代码
package com.peiyu.rpcs.bios; import java.io.IOException; public interface IRpcServers { void start() throws IOException; /** * 服务注册 * @param serviceInterface 服务接口 * @param impl 服务实现类 */ void register(Class serviceInterface, Class impl); }
实现类
package com.peiyu.rpcs.bios; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.lang.reflect.Method; import java.net.InetSocketAddress; import java.net.ServerSocket; import java.net.Socket; import java.util.HashMap; import java.util.concurrent.ArrayBlockingQueue; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; public class RpcServesrImpl implements IRpcServers { private int port; public static final HashMap<String, Class> serviceRegistry = new HashMap<String, Class>(); private static final ThreadPoolExecutor executor = new ThreadPoolExecutor(20, 20, 100, TimeUnit.MILLISECONDS, new ArrayBlockingQueue<Runnable>(100)); public RpcServesrImpl(int port) { this.port = port; } /** * 启动服务 */ @Override public void start() throws IOException { ServerSocket server = new ServerSocket(); server.bind(new InetSocketAddress(port)); System.out.println("Bio rpc 服务启动开始###端口###" + port); try { while (true) { System.out.println("等待客户端接入"); executor.execute(new ServersTask(server.accept())); } } catch (Exception e) { if (server != null) { server.close(); } } } @Override public void register(Class serviceInterface, Class impl) { serviceRegistry.put(serviceInterface.getName(), impl); } static class ServersTask implements Runnable { Socket client = null; public ServersTask(Socket socket) { this.client = socket; } ObjectInputStream input = null;//输入流 ObjectOutputStream output = null;//输出流 @Override public void run() { //接收客户端发送来的字节流,并转化成对象,反射调用服务实现者,获取执行结果 try { input = new ObjectInputStream(this.client.getInputStream()); String interfaceName = input.readUTF(); String methodName = input.readUTF(); Class<?>[] parameterType = (Class<?>[]) input.readObject(); Object[] args = (Object[]) input.readObject(); Class serverClass = serviceRegistry.get(interfaceName);//这里有问题服务器端去注册中心拉取实现类?? //但是如果不考虑注册中心,当作本地映射还挺好, //省的使用反射来通过接口来找实现类. if (serverClass == null) { throw new ClassNotFoundException(interfaceName + " not found"); } Method method = serverClass.getMethod(methodName, parameterType); Object result = method.invoke(serverClass.newInstance(), args); //执行结果反序列化返回给客户端 output = new ObjectOutputStream(this.client.getOutputStream()); output.writeObject(result); } catch (Exception e) { e.printStackTrace(); } finally { if (output != null) { try { output.close(); } catch (IOException e) { e.printStackTrace(); } } if (input != null) { try { input.close(); } catch (IOException e) { e.printStackTrace(); } } if (this.client != null) { try { this.client.close(); } catch (IOException e) { e.printStackTrace(); } } } } } }
mainapp
package com.peiyu.rpcs.bios; import java.io.IOException; public class MainApp { public static void main(String[] args) throws Exception { IRpcServers server = new RpcServesrImpl(8080); server.register(IOrderService.class, IOrderServiceImpl.class); server.start(); } }
一个接口一个实现类
package com.peiyu.rpcs.bios; public interface IOrderService { String getOrderDtoByUserId(int i); }
package com.peiyu.rpcs.bios; public class IOrderServiceImpl implements IOrderService{ @Override public String getOrderDtoByUserId(int i) { // TODO Auto-generated method stub return 100*i+""; } }
客户端
package com.peiyu.rpcs.bios; public class CLIENT { public static void main(String[] args) { long start =System.currentTimeMillis(); for (int i=0;i<200;i++){ try { IOrderService orderService= ProxyFactory.create(IOrderService.class,"127.0.0.1",8080); System.out.println(orderService.getOrderDtoByUserId(i)); }catch (Exception e){ e.printStackTrace(); } } long end=System.currentTimeMillis(); System.out.println("总耗时："+(end-start)); } }
代理
package com.peiyu.rpcs.bios; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; import java.net.Socket; public class ProxyFactory<T> { public static <T> T create(final Class<?> serviceInterface, final String ip, final int port) { //将本地的接口调用转换成JDK的动态代理，在动态代理中实现接口的远程调用 return (T) Proxy.newProxyInstance(serviceInterface.getClassLoader(), new Class<?>[]{serviceInterface}, new ProxyHandler(ip, port, serviceInterface)); } static class ProxyHandler implements InvocationHandler { private String ip; private int port; private Class<?> serviceInterface; public ProxyHandler(String ip, int port, Class<?> serviceInterface) { this.ip = ip; this.port = port; this.serviceInterface = serviceInterface; } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { Socket socket = null; ObjectOutputStream output = null; ObjectInputStream input = null; try { // 创建Socket客户端，根据指定地址连接远程服务提供者 socket = new Socket(ip, port); // 将远程服务调用所需的接口类、方法名、参数列表等编码后发送给服务提供者 output = new ObjectOutputStream(socket.getOutputStream()); output.writeUTF(serviceInterface.getName()); output.writeUTF(method.getName()); output.writeObject(method.getParameterTypes()); output.writeObject(args); // 同步阻塞等待服务器返回应答，获取应答后返回 input = new ObjectInputStream(socket.getInputStream()); return input.readObject(); } finally { if (socket != null) { socket.close(); } if (output != null) { output.close(); } if (input != null) { input.close(); } } } } }
本地接口
package com.peiyu.rpcs.bios; public interface IOrderService { String getOrderDtoByUserId(int i); }
总结与注意点:
1:output.writeUTF(serviceInterface.getName());这里面是 包名+接口名
2:这个是网上的代码,有些问题,注册中心serviceRegistry = new HashMap<String, Class>();写在了服务端,应该是客户端拉取才对,是不是客户端传output.writeUTF(com.peiyu.rpcs.bios.IOrderServiceImpl);才对呢?我想是,待考证(错误)
3.这个RPC如果不用serviceRegistry 映射,则需要通过接口找到实现类,这个就很麻烦
补充: 从注册中心拉取的是
//从ZK中获取地址 127.0.0.1:12345 String discover = serviceDiscovery.discover(rpcRequest.getClassName());
客户端拉取的是ip地址+端口号,比如说俩个服务,zookeeper存储接口名和地址,
192.168.126.166:20880 和192.168.166.188:20880, 客户端选择一个ip地址就实现了负载均衡,这样客户端还还是向其中一个服务发送端口,服务的从Map<接口,实现类.Class>来get一个impl.整个思想就完成了
atzhang
