Android – 通过Wi-Fi传递简单的字符串？
我有Wi-Fi直接演示。 我们可以将任何图像文件传输到其他设备。 当另一台设备连接并显示从图库发送图像时。 而在另一侧它显示发送的图像。 但是我想发送一个简单的字符串，而在另一边我想要烘烤那个字符串。 在这里，我发布了一个代码，他们已经实现了文件传输。 我在这段代码中很困惑。 我没有得到改变只传递字符串的地方。 请帮帮我。 谢谢。
DeviceDetailFragment.java
/** * A fragment that manages a particular peer and allows interaction with device * ie setting up network connection and transferring data. */ public class DeviceDetailFragment extends Fragment implements ConnectionInfoListener { protected static final int CHOOSE_FILE_RESULT_CODE = 20; private View mContentView = null; private WifiP2pDevice device; private WifiP2pInfo info; ProgressDialog progressDialog = null; @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { mContentView = inflater.inflate(R.layout.device_detail, null); mContentView.findViewById(R.id.btn_connect).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { WifiP2pConfig config = new WifiP2pConfig(); config.deviceAddress = device.deviceAddress; config.wps.setup = WpsInfo.PBC; if (progressDialog != null && progressDialog.isShowing()) { progressDialog.dismiss(); } progressDialog = ProgressDialog.show(getActivity(), "Press back to cancel", "Connecting to :" + device.deviceAddress, true, true // new DialogInterface.OnCancelListener() { // // @Override // public void onCancel(DialogInterface dialog) { // ((DeviceActionListener) getActivity()).cancelDisconnect(); // } // } ); ((DeviceActionListener) getActivity()).connect(config); } }); mContentView.findViewById(R.id.btn_disconnect).setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { ((DeviceActionListener) getActivity()).disconnect(); } }); mContentView.findViewById(R.id.btn_start_client).setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { // Allow user to pick an image from Gallery or other // registered apps Intent intent = new Intent(Intent.ACTION_GET_CONTENT); intent.setType("image/*"); startActivityForResult(intent, CHOOSE_FILE_RESULT_CODE); } }); return mContentView; } @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { // User has picked an image. Transfer it to group owner ie peer using // FileTransferService. Uri uri = data.getData(); TextView statusText = (TextView) mContentView.findViewById(R.id.status_text); statusText.setText("Sending: " + uri); Log.d(WiFiDirectActivity.TAG, "Intent----------- " + uri); Intent serviceIntent = new Intent(getActivity(), FileTransferService.class); serviceIntent.setAction(FileTransferService.ACTION_SEND_FILE); serviceIntent.putExtra(FileTransferService.EXTRAS_FILE_PATH, uri.toString()); serviceIntent.putExtra(FileTransferService.EXTRAS_GROUP_OWNER_ADDRESS, info.groupOwnerAddress.getHostAddress()); serviceIntent.putExtra(FileTransferService.EXTRAS_GROUP_OWNER_PORT, 8988); getActivity().startService(serviceIntent); } @Override public void onConnectionInfoAvailable(final WifiP2pInfo info) { if (progressDialog != null && progressDialog.isShowing()) { progressDialog.dismiss(); } this.info = info; this.getView().setVisibility(View.VISIBLE); // The owner IP is now known. TextView view = (TextView) mContentView.findViewById(R.id.group_owner); view.setText(getResources().getString(R.string.group_owner_text) + ((info.isGroupOwner == true) ? getResources().getString(R.string.yes) : getResources().getString(R.string.no))); // InetAddress from WifiP2pInfo struct. view = (TextView) mContentView.findViewById(R.id.device_info); view.setText("Group Owner IP - " + info.groupOwnerAddress.getHostAddress()); // After the group negotiation, we assign the group owner as the file // server. The file server is single threaded, single connection server // socket. if (info.groupFormed && info.isGroupOwner) { new FileServerAsyncTask(getActivity(), mContentView.findViewById(R.id.status_text)) .execute(); } else if (info.groupFormed) { // The other device acts as the client. In this case, we enable the // get file button. mContentView.findViewById(R.id.btn_start_client).setVisibility(View.VISIBLE); ((TextView) mContentView.findViewById(R.id.status_text)).setText(getResources() .getString(R.string.client_text)); } // hide the connect button mContentView.findViewById(R.id.btn_connect).setVisibility(View.GONE); } /** * Updates the UI with device data * * @param device the device to be displayed */ public void showDetails(WifiP2pDevice device) { this.device = device; this.getView().setVisibility(View.VISIBLE); TextView view = (TextView) mContentView.findViewById(R.id.device_address); view.setText(device.deviceAddress); view = (TextView) mContentView.findViewById(R.id.device_info); view.setText(device.toString()); } /** * Clears the UI fields after a disconnect or direct mode disable operation. */ public void resetViews() { mContentView.findViewById(R.id.btn_connect).setVisibility(View.VISIBLE); TextView view = (TextView) mContentView.findViewById(R.id.device_address); view.setText(R.string.empty); view = (TextView) mContentView.findViewById(R.id.device_info); view.setText(R.string.empty); view = (TextView) mContentView.findViewById(R.id.group_owner); view.setText(R.string.empty); view = (TextView) mContentView.findViewById(R.id.status_text); view.setText(R.string.empty); mContentView.findViewById(R.id.btn_start_client).setVisibility(View.GONE); this.getView().setVisibility(View.GONE); } /** * A simple server socket that accepts connection and writes some data on * the stream. */ public static class FileServerAsyncTask extends AsyncTask { private Context context; private TextView statusText; /** * @param context * @param statusText */ public FileServerAsyncTask(Context context, View statusText) { this.context = context; this.statusText = (TextView) statusText; } @Override protected String doInBackground(Void... params) { try { ServerSocket serverSocket = new ServerSocket(8988); Log.d(WiFiDirectActivity.TAG, "Server: Socket opened"); Socket client = serverSocket.accept(); Log.d(WiFiDirectActivity.TAG, "Server: connection done"); final File f = new File(Environment.getExternalStorageDirectory() + "/" + context.getPackageName() + "/wifip2pshared-" + System.currentTimeMillis() + ".jpg"); File dirs = new File(f.getParent()); if (!dirs.exists()) dirs.mkdirs(); f.createNewFile(); Log.d(WiFiDirectActivity.TAG, "server: copying files " + f.toString()); InputStream inputstream = client.getInputStream(); copyFile(inputstream, new FileOutputStream(f)); serverSocket.close(); return f.getAbsolutePath(); } catch (IOException e) { Log.e(WiFiDirectActivity.TAG, e.getMessage()); return null; } } /* * (non-Javadoc) * @see android.os.AsyncTask#onPostExecute(java.lang.Object) */ @Override protected void onPostExecute(String result) { if (result != null) { statusText.setText("File copied - " + result); Intent intent = new Intent(); intent.setAction(android.content.Intent.ACTION_VIEW); intent.setDataAndType(Uri.parse("file://" + result), "image/*"); context.startActivity(intent); } } /* * (non-Javadoc) * @see android.os.AsyncTask#onPreExecute() */ @Override protected void onPreExecute() { statusText.setText("Opening a server socket"); } } public static boolean copyFile(InputStream inputStream, OutputStream out) { byte buf[] = new byte[1024]; int len; long startTime=System.currentTimeMillis(); try { while ((len = inputStream.read(buf)) != -1) { out.write(buf, 0, len); } out.close(); inputStream.close(); long endTime=System.currentTimeMillis()-startTime; Log.v("","Time taken to transfer all bytes is : "+endTime); } catch (IOException e) { Log.d(WiFiDirectActivity.TAG, e.toString()); return false; } return true; } } FileTransferService.java
/** * A service that process each file transfer request ie Intent by opening a * socket connection with the WiFi Direct Group Owner and writing the file */ public class FileTransferService extends IntentService { private static final int SOCKET_TIMEOUT = 5000; public static final String ACTION_SEND_FILE = "com.example.android.wifidirect.SEND_FILE"; public static final String EXTRAS_FILE_PATH = "file_url"; public static final String EXTRAS_GROUP_OWNER_ADDRESS = "go_host"; public static final String EXTRAS_GROUP_OWNER_PORT = "go_port"; public FileTransferService(String name) { super(name); } public FileTransferService() { super("FileTransferService"); } /* * (non-Javadoc) * @see android.app.IntentService#onHandleIntent(android.content.Intent) */ @Override protected void onHandleIntent(Intent intent) { Context context = getApplicationContext(); if (intent.getAction().equals(ACTION_SEND_FILE)) { String fileUri = intent.getExtras().getString(EXTRAS_FILE_PATH); String host = intent.getExtras().getString(EXTRAS_GROUP_OWNER_ADDRESS); Socket socket = new Socket(); int port = intent.getExtras().getInt(EXTRAS_GROUP_OWNER_PORT); try { Log.d(WiFiDirectActivity.TAG, "Opening client socket - "); socket.bind(null); socket.connect((new InetSocketAddress(host, port)), SOCKET_TIMEOUT); Log.d(WiFiDirectActivity.TAG, "Client socket - " + socket.isConnected()); OutputStream stream = socket.getOutputStream(); ContentResolver cr = context.getContentResolver(); InputStream is = null; try { is = cr.openInputStream(Uri.parse(fileUri)); } catch (FileNotFoundException e) { Log.d(WiFiDirectActivity.TAG, e.toString()); } DeviceDetailFragment.copyFile(is, stream); Log.d(WiFiDirectActivity.TAG, "Client: Data written"); } catch (IOException e) { Log.e(WiFiDirectActivity.TAG, e.getMessage()); } finally { if (socket != null) { if (socket.isConnected()) { try { socket.close(); } catch (IOException e) { // Give up e.printStackTrace(); } } } } } } }
你可以这样做：
DeviceDetailFragment.java
@Override protected String doInBackground(Void... params) { ServerSocket serverSocket = null; Socket client = null; DataInputStream inputstream = null; try { serverSocket = new ServerSocket(8988); client = serverSocket.accept(); inputstream = new DataInputStream(client.getInputStream()); String str = inputstream.readUTF(); serverSocket.close(); return str; } catch (IOException e) { Log.e(WiFiDirectActivity.TAG, e.getMessage()); return null; }finally{ if(inputstream != null){ try{ inputstream.close(); } catch (IOException e) { Log.e(WiFiDirectActivity.TAG, e.getMessage()); } } if(client != null){ try{ client.close(); } catch (IOException e) { Log.e(WiFiDirectActivity.TAG, e.getMessage()); } } if(serverSocket != null){ try{ serverSocket.close(); } catch (IOException e) { Log.e(WiFiDirectActivity.TAG, e.getMessage()); } } } } @Override protected void onPostExecute(String result) { if (result != null) { Toast.makeText(..., result, ...).show();; } }
FileTransferService.java
@Override protected void onHandleIntent(Intent intent) { Context context = getApplicationContext(); if (intent.getAction().equals(ACTION_SEND_FILE)) { String host = intent.getExtras().getString(EXTRAS_GROUP_OWNER_ADDRESS); Socket socket = new Socket(); int port = intent.getExtras().getInt(EXTRAS_GROUP_OWNER_PORT); DataOutputStream stream = null; try { socket.connect((new InetSocketAddress(host, port)), SOCKET_TIMEOUT); stream = new DataOutputStream(socket.getOutputStream()); stream.writeUTF("a string"); } catch (IOException e) { Log.e(WiFiDirectActivity.TAG, e.getMessage()); } finally { if (stream != null) { try { stream.close(); } catch (IOException e) { e.printStackTrace(); } } if (socket != null) { if (socket.isConnected()) { try { socket.close(); } catch (IOException e) { e.printStackTrace(); } } } } } }