实现java RPC框架

主要利用socket通信，反射，代理实现类似RMI的RPC框架

首先是框架的代码

package framework;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.ServerSocket;import java.net.Socket;/** * RpcFramework *  * @author william.liangf */public class RpcFramework {    /**     * 暴露服务     *      * @param service 服务实现     * @param port 服务端口     * @throws Exception     */    public static void export(final Object service, int port) throws Exception {        if (service == null)            throw new IllegalArgumentException("service instance == null");        if (port <= 0 || port > 65535)            throw new IllegalArgumentException("Invalid port " + port);        System.out.println("Export service " + service.getClass().getName() + " on port " + port);        ServerSocket server = new ServerSocket(port);        for(;;) {            try {                final Socket socket = server.accept();//服务器端一旦收到消息，就创建一个线程进行处理                new Thread(new Runnable() {                    @Override                    public void run() {                        try {                            try {                                ObjectInputStream input = new ObjectInputStream(socket.getInputStream());                                try {                                    String methodName = input.readUTF();//service是服务器端提供服务的对象，但是，要通过获取到的调用方法的名称，参数类型，以及参数来选择对象的方法，并调用。获得方法的名称                                    Class<?>[] parameterTypes = (Class<?>[])input.readObject();//获得参数的类型                                    Object[] arguments = (Object[])input.readObject();//获得参数                                    ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());                                    try {                                        Method method = service.getClass().getMethod(methodName, parameterTypes);//通过反射机制获得方法                                        Object result = method.invoke(service, arguments);//通过反射机制获得类的方法，并调用这个方法                                        output.writeObject(result);//将结果发送                                    } catch (Throwable t) {                                        output.writeObject(t);                                    } finally {                                        output.close();                                    }                                } finally {                                    input.close();                                }                            } finally {                                socket.close();                            }                        } catch (Exception e) {                            e.printStackTrace();                        }                    }                }).start();            } catch (Exception e) {                e.printStackTrace();            }        }    }    /**     * 引用服务     *      * @param <T> 接口泛型     * @param interfaceClass 接口类型     * @param host 服务器主机名     * @param port 服务器端口     * @return 远程服务     * @throws Exception     *///原理是通过代理，获得服务器端接口的一个“代理”的对象。对这个对象的所有操作都会调用invoke函数，在invoke函数中，是将被调用的函数名，参数列表和参数发送到服务器，并接收服务器处理的结果    @SuppressWarnings("unchecked")    public static <T> T refer(final Class<T> interfaceClass, final String host, final int port) throws Exception {        if (interfaceClass == null)            throw new IllegalArgumentException("Interface class == null");        if (! interfaceClass.isInterface())            throw new IllegalArgumentException("The " + interfaceClass.getName() + " must be interface class!");        if (host == null || host.length() == 0)            throw new IllegalArgumentException("Host == null!");        if (port <= 0 || port > 65535)            throw new IllegalArgumentException("Invalid port " + port);        System.out.println("Get remote service " + interfaceClass.getName() + " from server " + host + ":" + port);        return (T) Proxy.newProxyInstance(interfaceClass.getClassLoader(), new Class<?>[] {interfaceClass}, new InvocationHandler() {            public Object invoke(Object proxy, Method method, Object[] arguments) throws Throwable {                Socket socket = new Socket(host, port);                try {                    ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());                    try {                        output.writeUTF(method.getName());                        output.writeObject(method.getParameterTypes());                        output.writeObject(arguments);                        ObjectInputStream input = new ObjectInputStream(socket.getInputStream());                        try {                            Object result = input.readObject();                            if (result instanceof Throwable) {                                throw (Throwable) result;                            }                            return result;                        } finally {                            input.close();                        }                    } finally {                        output.close();                    }                } finally {                    socket.close();                }            }        });    }}

服务接口

    package user;            public interface  HelloService {          String hello(String name);      }  

实现服务

    package user;            public class HelloServiceImpl implements HelloService{          public String hello(String name) {              return "Hello " + name;          }            }  

服务器

package user;import framework.RpcFramework;public class Server {public static void main(String []args) throws Exception {HelloService service = new HelloServiceImpl();RpcFramework.export(service, 1234); }}

客户机

package user;import framework.RpcFramework;public class Client {public static void main(String[] args) throws Exception {          HelloService service = RpcFramework.refer(HelloService.class, "127.0.0.1", 1234);          for (int i = 0; i < Integer.MAX_VALUE; i ++) {              String hello = service.hello("World" + i);              System.out.println(hello);              Thread.sleep(1000);          }      }  }