1/* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16package com.android.nfc.handover; 17 18import android.nfc.FormatException; 19import android.nfc.NdefMessage; 20import android.util.Log; 21 22import com.android.nfc.LlcpException; 23import com.android.nfc.NfcService; 24import com.android.nfc.DeviceHost.LlcpSocket; 25 26import java.io.ByteArrayOutputStream; 27import java.io.IOException; 28import java.util.Arrays; 29 30public final class HandoverClient { 31 private static final String TAG = "HandoverClient"; 32 private static final int MIU = 128; 33 // Max NDEF length to receive for Hr/Hs messages 34 private static final boolean DBG = false; 35 36 public NdefMessage sendHandoverRequest(NdefMessage msg) { 37 if (msg == null) return null; 38 39 NfcService service = NfcService.getInstance(); 40 41 LlcpSocket sock = null; 42 int offset = 0; 43 byte[] buffer = msg.toByteArray(); 44 ByteArrayOutputStream byteStream = new ByteArrayOutputStream(); 45 46 try { 47 sock = service.createLlcpSocket(0, MIU, 1, 1024); 48 if (sock == null) { 49 throw new IOException("Could not connect to socket."); 50 } 51 if (DBG) Log.d(TAG, "about to connect to service " + 52 HandoverServer.HANDOVER_SERVICE_NAME); 53 sock.connectToService(HandoverServer.HANDOVER_SERVICE_NAME); 54 55 int remoteMiu = sock.getRemoteMiu(); 56 if (DBG) Log.d(TAG, "about to send a " + buffer.length + " byte message"); 57 while (offset < buffer.length) { 58 int length = Math.min(buffer.length - offset, remoteMiu); 59 byte[] tmpBuffer = Arrays.copyOfRange(buffer, offset, offset+length); 60 if (DBG) Log.d(TAG, "about to send a " + length + " byte packet"); 61 sock.send(tmpBuffer); 62 offset += length; 63 } 64 65 // Now, try to read back the SNEP response 66 byte[] partial = new byte[sock.getLocalMiu()]; 67 NdefMessage handoverSelectMsg = null; 68 while (true) { 69 int size = sock.receive(partial); 70 if (size < 0) { 71 break; 72 } 73 byteStream.write(partial, 0, size); 74 try { 75 handoverSelectMsg = new NdefMessage(byteStream.toByteArray()); 76 // If we get here, message is complete 77 break; 78 } catch (FormatException e) { 79 // Ignore, and try to fetch more bytes 80 } 81 } 82 return handoverSelectMsg; 83 } catch (IOException e) { 84 if (DBG) Log.d(TAG, "couldn't connect to handover service"); 85 } catch (LlcpException e) { 86 if (DBG) Log.d(TAG, "couldn't connect to handover service"); 87 } finally { 88 if (sock != null) { 89 try { 90 if (DBG) Log.d(TAG, "about to close"); 91 sock.close(); 92 } catch (IOException e) { 93 // Ignore 94 } 95 } 96 try { 97 byteStream.close(); 98 } catch (IOException e) { 99 // Ignore 100 } 101 } 102 return null; 103 } 104} 105