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RPC例子

程序员文章站 2022-06-01 21:31:46
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RPC例子

首先,定义业务:

package com.service;

public interface HelloService {
    String sayHi(String name);
}
package com.service.impl;

import com.service.HelloService;

public class HelloServiceImpl implements HelloService{
    @Override
    public String sayHi(String name) {
        return "测试 ,"+name;
    }
}

服务端通信代码

package com.server;

import java.io.IOException;

public interface Server {

    void stop();

    public void start() throws IOException;

    public void register(Class serviceInterface, Class impl);

    public boolean isRunning();

    public int getPort();

}
package com.server.impl;

import com.server.Server;

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.ExecutorService;
import java.util.concurrent.Executors;

public class ServiceCenter implements Server{
    private static ExecutorService   executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());

    private static final HashMap<String, Class> serviceRegistry = new HashMap<String, Class>();

    private static boolean  isRunning = false;

    private static int  port;

    public ServiceCenter(int port) {
        this.port = port;
    }

    @Override
    public void stop() {
        isRunning = false;
        executor.shutdown();
    }

    @Override
    public void start() throws IOException {
        ServerSocket server = new ServerSocket();
        server.bind(new InetSocketAddress(port));
        System.out.println("启动--Server");
        try {
            while (true) {
                // 1.监听客户端的TCP连接,接到TCP连接后将其封装成task,由线程池执行
                executor.execute(new ServiceTask(server.accept()));
            }
        } finally {
            server.close();
        }
    }

    @Override
    public void register(Class serviceInterface, Class impl) {
        serviceRegistry.put(serviceInterface.getName(), impl);
    }

    @Override
    public boolean isRunning() {
        return isRunning;
    }

    @Override
    public int getPort() {
        return port;
    }


    private static class ServiceTask implements Runnable {
        Socket clent = null;

        public ServiceTask(Socket client) {
            this.clent = client;
        }

        @Override
        public void run() {
            ObjectInputStream input = null;
            ObjectOutputStream output = null;
            try {
                // 2.将客户端发送的码流反序列化成对象,反射调用服务实现者,获取执行结果
                input = new ObjectInputStream(clent.getInputStream());
                String serviceName = input.readUTF();
                String methodName = input.readUTF();
                Class<?>[] parameterTypes = (Class<?>[]) input.readObject();
                Object[] arguments = (Object[]) input.readObject();
                Class serviceClass = serviceRegistry.get(serviceName);
                if (serviceClass == null) {
                    throw new ClassNotFoundException(serviceName + " not found");
                }
                Method method = serviceClass.getMethod(methodName, parameterTypes);
                Object result = method.invoke(serviceClass.newInstance(), arguments);


                // 3.将执行结果反序列化,通过socket发送给客户端
                output = new ObjectOutputStream(clent.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 (clent != null) {
                    try {
                        clent.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }


        }
    }


}

服务端启动类

package com.start;

import com.service.HelloService;
import com.service.impl.HelloServiceImpl;
import com.server.Server;
import com.server.impl.ServiceCenter;
import java.io.IOException;

public class ServerStart {
    public static void main(String[] args) throws IOException {
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Server serviceServer = new ServiceCenter(8088);
                    serviceServer.register(HelloService.class, HelloServiceImpl.class);
                    serviceServer.start();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

}

客户端:需要引用业务接口代码 ,就是把服务端的接口打成jar包,注意!包的结构得一致;例如:服务端的业务代码包为:com.service.XxService.java ,所以jar包的结构也要这样

RPC例子

客户端通信代码

package com.client;

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.InetSocketAddress;
import java.net.Socket;

public class RPCClient<T> {
    @SuppressWarnings("unchecked")
    public static <T> T getRemoteProxyObj(final Class<?> serviceInterface, final InetSocketAddress addr) {
        // 1.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 InvocationHandler() {
                    @Override
                    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                        Socket socket = null;
                        ObjectOutputStream output = null;
                        ObjectInputStream input = null;
                        try {
                            // 2.创建Socket客户端,根据指定地址连接远程服务提供者
                            socket = new Socket();
                            socket.connect(addr);

                            // 3.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);

                            // 4.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();}
                        }
                    }
                });
    }
}

客户端测试远程调用

package com.test;

import com.client.RPCClient;
import com.service.HelloService;
import java.io.IOException;
import java.net.InetSocketAddress;

public class RpcClientTest {
    public static void main(String[] args) throws IOException {
        for (int i=0;i<100;i++){
            HelloService service = RPCClient
                    .getRemoteProxyObj(HelloService.class, new InetSocketAddress("192.168.3.63", 8088));
            System.out.println(service.sayHi("客户端传入的调用参数, ")+i);
        }
    }

}

运行结果:

RPC例子

备注:1、服务端的启动运行是用的 Java线程,线程会一直开启,客户端可以一直调用服务端的方法;2、服务端代码可以放在本机运行,也可以放在别的电脑上运行,需要更改代码中的IP地址,经过测试,放在本机的速度远远快于放在别的电脑上运行

相关标签: RPC