I want to print the text file from my application in android 8 through Bluetooth or WiFi. Please suggest me the solution.
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问题:
回答1:
this is a sample
package com.example.untitled2; import android.app.Activity; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothSocket; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; import java.io.IOException; import java.io.OutputStream; import java.util.Set; import java.util.UUID; public class MyActivity extends Activity { private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); /** * Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button btn = (Button) findViewById(R.id.button); btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); if (mBluetoothAdapter == null) { Toast.makeText(MyActivity.this, "no device", Toast.LENGTH_LONG).show(); } if (!mBluetoothAdapter.isEnabled()) { mBluetoothAdapter.enable(); } Set<BluetoothDevice> bluetoothDevices = mBluetoothAdapter.getBondedDevices(); if (bluetoothDevices.size() == 0) return; OutputStream mmOutStream; BluetoothDevice device = bluetoothDevices.iterator().next(); try { BluetoothSocket socket = device.createRfcommSocketToServiceRecord(MY_UUID); socket.connect(); mmOutStream = socket.getOutputStream(); /*String textPrint = ""+(char) 27 + (char)116 + (char) 27;*/ String textPrint = "this is example text"+(char)10; mmOutStream.flush(); mmOutStream.write(textPrint.getBytes()); mmOutStream.flush(); for (int i = 0; i < 10; i++) { mmOutStream.write(textPrint.getBytes()); } mmOutStream.flush(); //mmOutStream.wait(); mmOutStream.close(); socket.close(); } catch (IOException e) { Toast.makeText(MyActivity.this, e.getMessage(), Toast.LENGTH_LONG).show(); } } }); } } 回答2:
Here is my code [found online & modified as per my reqt] to connect to a Blue-tooth printer, works perfectly... tried n tested. :-)
package com.nvsoft.s2pay.mmsl.bluetoothprinter; import android.app.Activity; import java.io.IOException; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.Set; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothSocket; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.os.Bundle; import com.nvsoft.s2pay.sms.DynaCCSmsServiceConstants; import com.nvsoft.s2pay.util.StringUtil; import java.util.HashSet; import org.json.me.JSONObject; import org.slf4j.Logger; import org.slf4j.LoggerFactory; //This class is meant for wrapping the Bluetooth connecting interface provided by android devices....... //Basically is a state machine, and the communications will happen in a separate thread so as not to obstruct the main UI public class BTWrapperActivity extends Activity { public static final int REQUEST_CONNECT_BT = 0x2300;//8960 public static final int REQUEST_ENABLE_BT = 0x1000;//4096 public static final String DEVICES_DISCOVERED = "DD"; public static final String EXTRA_DEVICE_ADDRESS = DynaCCSmsServiceConstants.PRINTER_MAC_ADDRESS; private static final String ERROR = "ecode"; private static final String ERROR_MSG = "emsg"; public static int ERROR_CODE = 0; int request; static private BluetoothAdapter mBluetoothAdapter = null; static private Set<BluetoothDevice> btDevices = null; String deviceNames = null; JSONObject jobj = new JSONObject(); Intent parentIntent = null; BluetoothDevice selectedDevice = null; static private BluetoothSocket mbtSocket = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Bundle bundle = getIntent().getExtras(); deviceNames = bundle.getString(EXTRA_DEVICE_ADDRESS); parentIntent = getIntent(); request = bundle.getInt(BluetoothFilePrinter.REQUEST_CODE); try { if (request != DynaCCSmsServiceConstants.EXIT_ACTIVITY_REQUEST){ if (initDevicesList() != 0) { this.finish(); return; } } } catch (Exception ex) { getIntent().putExtra(ERROR, 701); getIntent().putExtra(ERROR_MSG, ex.getMessage()); finish(); return; } // Register the Broadcast receiver for handling new BT device discovery //IntentFilter btIntentFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND); //this.registerReceiver(mBTReceiver, new IntentFilter(DynaCCSmsServiceConstants.ACTION_EXIT_ACTIVITY)); this.registerReceiver(mBTReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND)); this.registerReceiver(mBTReceiver, new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED)); this.registerReceiver(mBTReceiver, new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECT_REQUESTED)); this.registerReceiver(mBTReceiver, new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECTED)); this.registerReceiver(mBTReceiver, new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED)); this.registerReceiver(mBTReceiver, new IntentFilter(Intent.ACTION_SCREEN_ON)); this.registerReceiver(mBTReceiver, new IntentFilter(Intent.ACTION_SCREEN_OFF)); if (request == DynaCCSmsServiceConstants.EXIT_ACTIVITY_REQUEST) { unregisterReceiver(mBTReceiver); this.finish(); } } public static BluetoothSocket getSocket() { return mbtSocket; } private void flushData() { try { /*if (mbtSocket != null) { mbtSocket.close(); mbtSocket = null; }*/ if (mBluetoothAdapter != null) { mBluetoothAdapter.cancelDiscovery(); } if (btDevices != null) { btDevices.clear(); btDevices = null; } if (deviceNames!=null) { deviceNames = null; } finalize(); } catch(Exception ex){ getIntent().putExtra(ERROR, 702); getIntent().putExtra(ERROR_MSG, ex.getMessage()); } catch (Throwable e) { getIntent().putExtra(ERROR, 702); getIntent().putExtra(ERROR_MSG, e.getMessage()); } } // This method will Connect to our SPP Bluetooth Device after discovering and pairing if required // Do not forget to add the permission for Bluetooth to use this method // Also this method is very tightly coupled with the above method, for getting the status of bt connection private int initDevicesList() { // Flush any Pending Data to rediscover devices if (request == DynaCCSmsServiceConstants.DISCOVER_REQUEST) { flushData(); } // Get the Bluetooth Adaptor of the device mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); if (mBluetoothAdapter == null) { return -1; } if (mBluetoothAdapter.isDiscovering()) { mBluetoothAdapter.cancelDiscovery(); } // ENABLE BLUETOOTH on DEVICE if not ALREADY TURNED ON Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); try { startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT); } catch (Exception ex) { return -2; } return 0; } // End getDeviceList @Override protected void onActivityResult(int reqCode, int resultCode, Intent intent) { super.onActivityResult(reqCode, resultCode, intent); if (intent == null) { intent = getIntent(); } switch (reqCode) { case REQUEST_ENABLE_BT: if (request == DynaCCSmsServiceConstants.DISCOVER_REQUEST) { if (resultCode == RESULT_OK) { // Start getting the paired devices list Set<BluetoothDevice> btDeviceList = mBluetoothAdapter.getBondedDevices(); // If there are paired devices try { if (btDeviceList.size() > 0) { // Loop through paired devices for (BluetoothDevice device : btDeviceList) { jobj.put(device.getName(), device.getAddress()); if (btDeviceList.contains(device) == false) { btDevices.add(device); // Add the device to the device list jobj.put(device.getName(), device.getAddress()); } } if (jobj != null) { intent.putExtra(DEVICES_DISCOVERED, jobj.toString()); } setResult(Activity.RESULT_OK, intent); finish(); } else { mBluetoothAdapter.startDiscovery(); } } catch (Exception ex) { getIntent().putExtra(ERROR, 704); getIntent().putExtra(ERROR_MSG, ex.getMessage()); setResult(Activity.RESULT_CANCELED, intent); } } else { getIntent().putExtra(ERROR, 704); getIntent().putExtra(ERROR_MSG, "Permission to enable Bluetooth on the device was denied. Please enable Bluetooth and retry."); setResult(Activity.RESULT_CANCELED, intent); finish(); } }//end of discovery else if (request == DynaCCSmsServiceConstants.CONNECT_REQUEST || request == DynaCCSmsServiceConstants.PRINT_REQUEST) { if (resultCode == RESULT_OK) { if (deviceNames!=null) { connect(deviceNames); }else{ getIntent().putExtra(ERROR, 704); getIntent().putExtra(ERROR_MSG, "Could not find any printer."); setResult(Activity.RESULT_CANCELED, intent); finish(); } }else{ getIntent().putExtra(ERROR, 704); getIntent().putExtra(ERROR_MSG, "Permission to enable Bluetooth on the device was denied. Please enable Bluetooth and retry."); setResult(Activity.RESULT_CANCELED, intent); finish(); } } break; case REQUEST_CONNECT_BT: if (resultCode == Activity.RESULT_OK) { setResult(Activity.RESULT_OK, intent); } else { setResult(Activity.RESULT_CANCELED, intent); } finish(); break; } } private final BroadcastReceiver mBTReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); // Get the BluetoothDevice object from the Intent BluetoothDevice device ; // When discovery finds a device if (BluetoothDevice.ACTION_FOUND.equals(action)) { device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); try { // No paired device found if (btDevices == null) { btDevices = new HashSet<BluetoothDevice>(); btDevices.add(device); jobj.put(device.getName(), device.getAddress()); } else { if (!btDevices.contains(device)) { btDevices.add(device); jobj.put(device.getName(), device.getAddress()); } } intent.putExtra(DEVICES_DISCOVERED, jobj.toString()); } catch (Exception ex) { getIntent().putExtra(ERROR, 705); getIntent().putExtra(ERROR_MSG, ex.getMessage()); } } else if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) { intent.putExtra("IS_CONNECTED", true); } else if (BluetoothDevice.ACTION_ACL_DISCONNECT_REQUESTED.equals(action)) { //#ifndef REMOVE_DEBUG logger.debug("BTWrapperActivity - ", " Device is about to disconnect"); //#endif } else if (BluetoothDevice.ACTION_ACL_DISCONNECTED.equals(action)) { //#ifndef REMOVE_DEBUG logger.debug("BTWrapperActivity - ", "Device has disconnected"); //#endif intent.putExtra("IS_CONNECTED", false); } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) { //#ifndef REMOVE_DEBUG logger.debug("BTWrapperActivity - ", "DISCOVERY FINISSHED"); //#endif if (request == DynaCCSmsServiceConstants.DISCOVER_REQUEST) { intent.putExtra(DEVICES_DISCOVERED, jobj.toString()); sendDiscoveryResult(intent); } }else if(Intent.ACTION_SCREEN_ON.equals(action)){ //#ifndef REMOVE_DEBUG logger.debug("BTWrapperActivity - ", "SCREEN ON"); //#endif }else if(Intent.ACTION_SCREEN_OFF.equals(action)){ //#ifndef REMOVE_DEBUG logger.debug("BTWrapperActivity - ", "SCREEN OFF"); //#endif } } }; private void connect(final String deviceAddress) { mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); if (mBluetoothAdapter == null) { return; } else { selectedDevice = mBluetoothAdapter.getRemoteDevice(deviceAddress); } // Cancel the dicovery if still going on if (mBluetoothAdapter.isDiscovering()) { mBluetoothAdapter.cancelDiscovery(); } if (mbtSocket != null) { try { mbtSocket.close(); } catch (IOException ex) { getIntent().putExtra(ERROR, 706); getIntent().putExtra(ERROR_MSG, ex.getMessage()); setResult(Activity.RESULT_CANCELED, getIntent()); finish(); } mbtSocket = null; } // Try to connect with the selected device, // made the thread different as the connecting proceedure might break down the system Thread connectThread = new Thread(new Runnable() { @Override public void run() { Intent intent = getIntent(); String errMsg = ""; try { try { Method m = selectedDevice.getClass().getMethod("createInsecureRfcommSocket", new Class[]{int.class}); try { mbtSocket = (BluetoothSocket) m.invoke(selectedDevice, 1); } catch (IllegalArgumentException e) { errMsg = e.getMessage(); getIntent().putExtra(ERROR, 707); getIntent().putExtra(ERROR_MSG, errMsg); } catch (IllegalAccessException e) { errMsg = e.getMessage(); getIntent().putExtra(ERROR, 708); getIntent().putExtra(ERROR_MSG, errMsg); } catch (InvocationTargetException e) { errMsg = e.getMessage(); getIntent().putExtra(ERROR, 709); getIntent().putExtra(ERROR_MSG, errMsg); }finally{ if (!StringUtil.isEmpty(errMsg) && intent.getExtras().getInt(ERROR)>0) { setResult(Activity.RESULT_CANCELED, getIntent()); finish(); } } } catch (SecurityException e) { errMsg = e.getMessage(); getIntent().putExtra(ERROR, 710); getIntent().putExtra(ERROR_MSG, errMsg); setResult(Activity.RESULT_CANCELED, getIntent()); finish(); } catch (NoSuchMethodException e) { errMsg = e.getMessage(); getIntent().putExtra(ERROR, 711); getIntent().putExtra(ERROR_MSG, errMsg); setResult(Activity.RESULT_CANCELED, getIntent()); finish(); } //mbtSocket = selectedDevice.createRfcommSocketToServiceRecord(SPP_UUID); ERROR_CODE = intent.getExtras().getInt(ERROR); //#ifndef REMOVE_DEBUG logger.debug("ERROR = ", ERROR_CODE); //#endif if (ERROR_CODE == 0) { mbtSocket.connect(); //#ifndef REMOVE_DEBUG logger.debug("@@BTWrapperActivity - ", "Connected to selectedDevice = " + (String) intent.getExtras().get(EXTRA_DEVICE_ADDRESS)); //#endif intent.putExtra("IS_CONNECTED", true); setResult(Activity.RESULT_OK, intent); } else { intent.putExtra(ERROR, ERROR_CODE); intent.putExtra(ERROR_MSG,errMsg); setResult(Activity.RESULT_CANCELED, intent); finish(); } } catch (IOException ex) { getIntent().putExtra(ERROR, 712); getIntent().putExtra(ERROR_MSG, "Unable to Connect to the Printer. Please verify the printer settings and try again."); getIntent().putExtra("IS_CONNECTED", false); ex.printStackTrace(); setResult(Activity.RESULT_CANCELED, intent); finish(); }finally{ finish(); } } }); connectThread.start(); } private Runnable socketErrorRunnable = new Runnable() { @Override public void run() { getIntent().putExtra(ERROR, 714); getIntent().putExtra(ERROR_MSG,"Cannot establish connection"); mBluetoothAdapter.startDiscovery(); } }; protected void onStop() { unregisterReceiver(mBTReceiver); super.onStop(); } private void sendDiscoveryResult(Intent mIntent){ mIntent.putExtra(DEVICES_DISCOVERED, jobj.toString()); setResult(Activity.RESULT_OK, mIntent); finish(); } private String getDisplayMessage(){ String message = "Please Wait!!"; switch(request) { case DynaCCSmsServiceConstants.DISCOVER_REQUEST : message = "Discovery in progress!!"; break; case DynaCCSmsServiceConstants.CONNECT_REQUEST: message = "Connecting...Please Wait!!"; break; case DynaCCSmsServiceConstants.PRINT_REQUEST: message = "Printing in progress!!"; break; } return message; }} // End of class definition 文章来源: Printing with android