java echo server

NotNIOEchoServer.java

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * Created by nanika on 2014/12/07.
 */
public class Server {

	int port = 9999;
	Thread runThread = new Thread();

	public void simpleStart() throws IOException {

		ServerSocket serverSocket = new ServerSocket(port);
		serverSocket.setReuseAddress(true);

		Socket clientSocket = serverSocket.accept();
		System.out.println("server accepted");
		InputStream in = clientSocket.getInputStream();
		OutputStream out = clientSocket.getOutputStream();

		int receiveSize = 0;
		byte[] bytebuf = new byte[32];
		while ((receiveSize = in.read(bytebuf)) != -1) {
			out.write(bytebuf, 0, receiveSize);
		}
		clientSocket.close();
		System.out.println("server closed");

	}

	public void loop() throws IOException {

		ServerSocket serverSocket = new ServerSocket(port);
		serverSocket.setReuseAddress(true);

		for (;;) {
			Socket clientSocket = serverSocket.accept();
			System.out.println("server accepted");
			InputStream in = clientSocket.getInputStream();
			OutputStream out = clientSocket.getOutputStream();

			int receiveSize = 0;
			byte[] bytebuf = new byte[32];
			while ((receiveSize = in.read(bytebuf)) != -1) {
				out.write(bytebuf, 0, receiveSize);
			}
			clientSocket.close();
			System.out.println("server closed");

		}
	}

	int threadNum = 2;
	ExecutorService executor = Executors.newFixedThreadPool(threadNum);

	public void multiThread() throws IOException {
		ServerSocket serverSocket = new ServerSocket(port);
		serverSocket.setReuseAddress(true);

		for (;;) {
			final Socket clientSocket = serverSocket.accept();
			System.out.println("server accepted");
			Callable task = new Callable() {
				@Override
				public Object call() throws Exception {
					InputStream in = clientSocket.getInputStream();
					OutputStream out = clientSocket.getOutputStream();

					int receiveSize = 0;
					byte[] bytebuf = new byte[32];
					while ((receiveSize = in.read(bytebuf)) != -1) {
						out.write(bytebuf, 0, receiveSize);
					}
					clientSocket.close();
					System.out.println("server closed");
					return null;
				}
			};
			executor.submit(task);
		}
	}


}