问在android应用程序中需要服务器客户端连接代码

EN

Socket socket;
InputStream is;
OutputStream os;
String hostname;
int port;

public void connect() throws IOException {
  socket = new Socket(hostname, port);
  is = socket.getInputStream();
  os = socket.getOutputStream();
}

public void send(String data) throws IOException {
  if(socket != null && socket.isConnected()) {
    os.write(data.getBytes());
    os.flush();
  }
}

public String read() throws IOException {
  String rtn = null;
  int ret;
  byte buf[] = new byte[512];
  while((ret = is.read(buf)) != -1) {
    rtn += new String(buf, 0, ret, "UTF-8");
  }
  return rtn;
}

public void disconnect() throws IOException {
  try {
    is.close();
    os.close();
    socket.close();
  } finally {
    is = null;
    os = null;
    socket = null;
  }

}