1.1 协议

import org.apache.hadoop.io.Text;
import org.apache.hadoop.ipc.VersionedProtocol;
public interface MyProtocol extendsVersionedProtocol {
	public Text test(Text t);
}

import java.io.IOException;
import java.net.InetSocketAddress;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.ipc.RPC;
public class MyClient {

	public MyProtocol myProtocol;

	public MyClient() throws IOException {
		InetSocketAddress addr = new InetSocketAddress("localhost", 8888);
		myProtocol = (MyProtocol)RPC.waitForProxy(MyProtocol.class, 1, addr,
		new Configuration());
	}

	public void sendClientMsg() {
		System.out.println("I am client,waiting server's data...");
		Text result = myProtocol.test(new Text("message from client"));
		System.out.println(result.toString());
	}

	public static void main(String[] args) throws IOException {
		MyClient client = new MyClient();
		client.sendClientMsg();
	}
}

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.ipc.RPC;
import org.apache.hadoop.ipc.RPC.Server;
public class MyServer implements MyProtocol {

	public void initialize() throws InterruptedException, IOException {
		Server server =RPC.getServer(this, "localhost", 8888,
		new Configuration());
		server.start();
	}

	@Override
	public long getProtocolVersion(String s1, long s2) throws IOException {
		return 1;
	}

	@Override
	public Text test(Text t) {
		if ("message from client".equals(t.toString()))
		return new Text("data from server");
		return new Text("who are you");
	}

	public static void main(String[] args) throws InterruptedException,
		IOException {
		MyServer server = new MyServer();
		server.initialize();
	}
}