JavaでSocket通信

これを使えば

"俺サーバ"も書けちゃうね！
ありがちだけどAndroidをタッチパッド代わりに使うアプリだって書けちゃう！

ソース

MyServer.java

import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class MyServer extends Thread {

  private int serverPort;
  private int maxConnection;

  public MyServer(int serverPort, int maxConnection) {
    this.serverPort = serverPort;
    this.maxConnection = maxConnection;
  }

  @Override
  public void run() {
    ServerSocket serverSocket = null;
    Socket socket = null;

    try {
      serverSocket = new ServerSocket(serverPort, maxConnection);

      socket = serverSocket.accept();
      new ServerProcess(socket).start();

    } catch (IOException e) {
      e.printStackTrace();
      System.exit(1);
    } finally {
      if (serverSocket != null) {
        try {
          serverSocket.close();
        } catch (IOException e) {
          e.printStackTrace();
          System.exit(1);
        }
      }
    }
  }

  private class ServerProcess extends Thread {
    private Socket socket;

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

    @Override
    public void run() {
      InputStream stream = null;
      byte buffer[] = new byte[1024];
      int length;
      StringBuffer recvMessage = new StringBuffer();

      try {
        stream = socket.getInputStream();

        while (true) {
          length = stream.read(buffer);
          if (length > 0) {
            recvMessage.append(new String(buffer, 0, length));
          } else {
            break;
          }
        }

        System.out.println(recvMessage.toString());
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }
}

MyClient.java

import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;

public class MyClient {
  private String serverAddress;
  private int serverPort;

  public MyClient(String serverAddress, int serverPort) {
    this.serverAddress = serverAddress;
    this.serverPort = serverPort;
  }

  public boolean sendMessage(String message) {
    Socket socket = null;
    OutputStream stream = null;

    try {
      socket = new Socket(serverAddress, serverPort);
      stream = socket.getOutputStream();
      stream.write(message.getBytes());
      return true;
    } catch (IOException e) {
      e.printStackTrace();
      return false;
    } finally {
      try {
        if (socket != null) {
          socket.close();
        }
        if (stream != null) {
          stream.close();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }
}

Main.java

public class Main {
  public static void main(String[] args) {
    MyServer server = new MyServer(6001, 1);
    server.start();
    MyClient client = new MyClient("localhost", 6001);
    client.sendMessage("Hello Tomorrow!!");
  }
}

実行結果

Hello Tomorrow!!