public class SocketServer {
  public static void main(String[] args) {
    try {
      // 创建一个服务器ServerSocket，并指定端口号为5120
      ServerSocket mServerSocket = new ServerSocket(5120);
      // 等待客户端连接
      Socket socket = mServerSocket.accept();
      // 连接上客户端后，获取客户端输入流信息
      InputStream is = socket.getInputStream();
      // 通过获取缓冲数据方式来读取文本信息
      BufferedReader br = new BufferedReader(new InputStreamReader(is));
      // 获取文本信息
      String line;
      StringBuffer sb = new StringBuffer();
      while ((line = br.readLine()) != null) {
        sb.append(line);
      }
      System.out.println(sb.toString());
      socket.shutdownInput();
      // 收到客户端信息后，回复客户端信息
      OutputStream os = socket.getOutputStream();
      PrintWriter pw = new PrintWriter(os);
      pw.write("收到回复，我是服务端");
      pw.flush();
      // 关闭流通常放在finally中操作
      os.close();
      br.close();
      is.close();
      pw.close();
      socket.close();
      mServerSocket.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

public class ClientSocket {
  public static void main(String[] args) {
    try {
      // 创建客户端Socket,指定主机和端口
      Socket mSocket = new Socket("localhost", 5120);
      // 通过输入流向服务器发数据
      OutputStream os = mSocket.getOutputStream();
      PrintWriter pw = new PrintWriter(os);
      pw.write("来自客户端Socket的数据，你收到了吗？");
      pw.flush();
      mSocket.shutdownOutput();
      // 收取服务端的回复信息
      InputStream is = mSocket.getInputStream();
      // 通过获取缓冲数据方式来读取文本信息
      BufferedReader br = new BufferedReader(new InputStreamReader(is));
      // 获取文本信息
      String line;
      StringBuffer sb = new StringBuffer();
      while ((line = br.readLine()) != null) {
        sb.append(line);
      }
      System.out.println(sb.toString());
      // 关闭流通常放在finally中操作
      br.close();
      is.close();
      pw.close();
      os.close();
      mSocket.close();
    } catch (UnknownHostException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
}