一个RPC的demo （good）

从下面的例子中可以看到，Consumer(client)的代码中引用了Provider部分的class，本例中是

com.provider.EchoServiceImpl和com.provider.EchoService

即这些class在Consumer(client)和Provider(server)都需要部署

Provider:

package com.provider;

public interface EchoService {
String echo(String msg);
}

package com.provider;

public class EchoServiceImpl implements EchoService {
@Override
public String echo(String msg) {
return msg != null ? msg + "-->I am OK." : " pass null.";
}
}

package com.provider;

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.concurrent.Executor;
import java.util.concurrent.Executors;

public class RpcProvider {
private static Executor executor = Executors.newFixedThreadPool(20);

public static void provide(String host, int port) throws IOException {
ServerSocket serverSocket = new ServerSocket();
serverSocket.bind(new InetSocketAddress(host, port));
try {
while (true) {
System.out.println("one input coming");
executor.execute(new ProviderTask(serverSocket.accept()));
System.out.println("execute one input");
}
} finally {
serverSocket.close();
}

}

private static class ProviderTask implements Runnable {
private Socket socket;

public ProviderTask(Socket socket) {
this.socket = socket;
}

@Override
public void run() {
ObjectInputStream inputStream = null;
ObjectOutputStream outputStream = null;
try {
inputStream = new ObjectInputStream(socket.getInputStream());
String className = inputStream.readUTF();
Class<?> service = Class.forName(className);
String methodName = inputStream.readUTF();
Class<?>[] parameterTypes = (Class<?>[]) inputStream.readObject();
Object[] arguments = (Object[]) inputStream.readObject();
Method method = service.getMethod(methodName, parameterTypes);
Object result = method.invoke(service.newInstance(), arguments);
outputStream = new ObjectOutputStream(socket.getOutputStream());
outputStream.writeObject(result);
} catch (Exception e) {
e.printStackTrace();
} finally {
close(inputStream);
close(outputStream);
close(socket);
}
}

}

public static void close(AutoCloseable closeable) {
if (closeable != null) {
try {
closeable.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

package com.provider;

import java.io.IOException;

public class ProviderMain {
public static void main(String[] args) {
try {
RpcProvider.provide("localhost", 8088);
} catch (IOException e) {
e.printStackTrace();
}
}
}

Consumer:

package com.consumer;

import com.provider.RpcProvider;

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 RpcConsumer {

public Object consume(Class<?> echoServiceClass, InetSocketAddress socketAddress) {
return Proxy.newProxyInstance(echoServiceClass.getClassLoader(), new Class<?>[]{echoServiceClass.getInterfaces()[0]}, new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
Socket socket = null;
ObjectOutputStream outputStream = null;
ObjectInputStream inputStream = null;
try {
socket = new Socket();
socket.connect(socketAddress);
outputStream = new ObjectOutputStream(socket.getOutputStream());
outputStream.writeUTF(echoServiceClass.getName());
outputStream.writeUTF(method.getName());
outputStream.writeObject(method.getParameterTypes());
outputStream.writeObject(args);
inputStream = new ObjectInputStream(socket.getInputStream());
return inputStream.readObject();
} finally {
RpcProvider.close(outputStream);
RpcProvider.close(inputStream);
RpcProvider.close(socket);
}
}
});
}

}

package com.consumer;

import com.provider.EchoService;
import com.provider.EchoServiceImpl;

import java.net.InetSocketAddress;

public class ConsumerMain {
public static void main(String[] args) {
RpcConsumer rpcConsumer = new RpcConsumer();
EchoService echoService = (EchoService) rpcConsumer.consume(EchoServiceImpl.class, new InetSocketAddress("localhost", 8088));
System.out.println(echoService.echo(ConsumerMain.class.getCanonicalName()));
}

}