如何通过套接字将Android数据包发送到服务器？

Question

如何将Android数据包发送到套接字服务器？我当前的代码导致应用程序退出。三星Galaxy GT-P5210上的Android 4.2.2。我可以使用WiFiP2pManager成功连接到远程设备。

                    String wr_data = ">04" + (char) 0x0D + (char) 0x0A;     // GAA 04Jan2018
                    Socket client = null;
                    Log.d(WiFiDirectActivity.TAG, "Start socket connection");
                    toast = Toast.makeText(context, "Start socket connection", duration);
                    toast.show();
                    try {

                        InetAddress cc3200Address = InetAddress.getByName("192.168.49.146");

                        client = new Socket(cc3200Address, PORT);

                        OutputStream os = client.getOutputStream();

// InputStream is = client.getInputStream（）; // GAA 04Jan2018

                            len = wr_data.length();
                            os.write(wr_data.getBytes(), 0, len);

                        os.close();

// inputStream.close（）;

                    } catch (IOException e) {
                        Log.e(WiFiDirectActivity.TAG, e.getMessage());
                    } finally {
                        if (client != null) {
                            if (client.isConnected()) {
                                try {
                                    client.close();
                                } catch (IOException e) {
                                    // Give up
                                    e.printStackTrace();
                                }
                            }
                        }
                    }