nxpandroid | 64fd68c | 2015-09-23 16:45:15 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2010 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 | */ |
| 16 | |
| 17 | package com.android.nfc.ndefpush; |
| 18 | |
| 19 | import android.util.Log; |
| 20 | |
| 21 | import android.nfc.NdefMessage; |
| 22 | import android.nfc.FormatException; |
| 23 | |
| 24 | import java.io.ByteArrayInputStream; |
| 25 | import java.io.DataInputStream; |
| 26 | import java.io.ByteArrayOutputStream; |
| 27 | import java.io.DataOutputStream; |
| 28 | |
| 29 | /** |
| 30 | * Implementation of the NDEF Push Protocol. |
| 31 | */ |
| 32 | public class NdefPushProtocol { |
| 33 | public static final byte ACTION_IMMEDIATE = (byte) 0x01; |
| 34 | public static final byte ACTION_BACKGROUND = (byte) 0x02; |
| 35 | |
| 36 | private static final String TAG = "NdefMessageSet"; |
| 37 | private static final byte VERSION = 1; |
| 38 | |
| 39 | private int mNumMessages; |
| 40 | private byte[] mActions; |
| 41 | private NdefMessage[] mMessages; |
| 42 | |
| 43 | public NdefPushProtocol(NdefMessage msg, byte action) { |
| 44 | mNumMessages = 1; |
| 45 | mActions = new byte[1]; |
| 46 | mActions[0] = action; |
| 47 | mMessages = new NdefMessage[1]; |
| 48 | mMessages[0] = msg; |
| 49 | } |
| 50 | |
| 51 | public NdefPushProtocol(byte[] actions, NdefMessage[] messages) { |
| 52 | if (actions.length != messages.length || actions.length == 0) { |
| 53 | throw new IllegalArgumentException( |
| 54 | "actions and messages must be the same size and non-empty"); |
| 55 | } |
| 56 | |
| 57 | // Keep a copy of these arrays |
| 58 | int numMessages = actions.length; |
| 59 | mActions = new byte[numMessages]; |
| 60 | System.arraycopy(actions, 0, mActions, 0, numMessages); |
| 61 | mMessages = new NdefMessage[numMessages]; |
| 62 | System.arraycopy(messages, 0, mMessages, 0, numMessages); |
| 63 | mNumMessages = numMessages; |
| 64 | } |
| 65 | |
| 66 | public NdefPushProtocol(byte[] data) throws FormatException { |
| 67 | ByteArrayInputStream buffer = new ByteArrayInputStream(data); |
| 68 | DataInputStream input = new DataInputStream(buffer); |
| 69 | |
| 70 | // Check version of protocol |
| 71 | byte version; |
| 72 | try { |
| 73 | version = input.readByte(); |
| 74 | } catch (java.io.IOException e) { |
| 75 | Log.w(TAG, "Unable to read version"); |
| 76 | throw new FormatException("Unable to read version"); |
| 77 | } |
| 78 | |
| 79 | if(version != VERSION) { |
| 80 | Log.w(TAG, "Got version " + version + ", expected " + VERSION); |
| 81 | throw new FormatException("Got version " + version + ", expected " + VERSION); |
| 82 | } |
| 83 | |
| 84 | // Read numMessages |
| 85 | try { |
| 86 | mNumMessages = input.readInt(); |
| 87 | } catch(java.io.IOException e) { |
| 88 | Log.w(TAG, "Unable to read numMessages"); |
| 89 | throw new FormatException("Error while parsing NdefMessageSet"); |
| 90 | } |
| 91 | if(mNumMessages == 0) { |
| 92 | Log.w(TAG, "No NdefMessage inside NdefMessageSet packet"); |
| 93 | throw new FormatException("Error while parsing NdefMessageSet"); |
| 94 | } |
| 95 | |
| 96 | // Read actions and messages |
| 97 | mActions = new byte[mNumMessages]; |
| 98 | mMessages = new NdefMessage[mNumMessages]; |
| 99 | for(int i = 0; i < mNumMessages; i++) { |
| 100 | // Read action |
| 101 | try { |
| 102 | mActions[i] = input.readByte(); |
| 103 | } catch(java.io.IOException e) { |
| 104 | Log.w(TAG, "Unable to read action for message " + i); |
| 105 | throw new FormatException("Error while parsing NdefMessageSet"); |
| 106 | } |
| 107 | // Read message length |
| 108 | int length; |
| 109 | try { |
| 110 | length = input.readInt(); |
| 111 | } catch(java.io.IOException e) { |
| 112 | Log.w(TAG, "Unable to read length for message " + i); |
| 113 | throw new FormatException("Error while parsing NdefMessageSet"); |
| 114 | } |
| 115 | byte[] bytes = new byte[length]; |
| 116 | // Read message |
| 117 | int lengthRead; |
| 118 | try { |
| 119 | lengthRead = input.read(bytes); |
| 120 | } catch(java.io.IOException e) { |
| 121 | Log.w(TAG, "Unable to read bytes for message " + i); |
| 122 | throw new FormatException("Error while parsing NdefMessageSet"); |
| 123 | } |
| 124 | if(length != lengthRead) { |
| 125 | Log.w(TAG, "Read " + lengthRead + " bytes but expected " + |
| 126 | length); |
| 127 | throw new FormatException("Error while parsing NdefMessageSet"); |
| 128 | } |
| 129 | // Create and store NdefMessage |
| 130 | try { |
| 131 | mMessages[i] = new NdefMessage(bytes); |
| 132 | } catch(FormatException e) { |
| 133 | throw e; |
| 134 | } |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | public NdefMessage getImmediate() { |
| 139 | // Find and return the first immediate message |
| 140 | for(int i = 0; i < mNumMessages; i++) { |
| 141 | if(mActions[i] == ACTION_IMMEDIATE) { |
| 142 | return mMessages[i]; |
| 143 | } |
| 144 | } |
| 145 | return null; |
| 146 | } |
| 147 | |
| 148 | public byte[] toByteArray() { |
| 149 | ByteArrayOutputStream buffer = new ByteArrayOutputStream(1024); |
| 150 | DataOutputStream output = new DataOutputStream(buffer); |
| 151 | |
| 152 | try { |
| 153 | output.writeByte(VERSION); |
| 154 | output.writeInt(mNumMessages); |
| 155 | for(int i = 0; i < mNumMessages; i++) { |
| 156 | output.writeByte(mActions[i]); |
| 157 | byte[] bytes = mMessages[i].toByteArray(); |
| 158 | output.writeInt(bytes.length); |
| 159 | output.write(bytes); |
| 160 | } |
| 161 | } catch(java.io.IOException e) { |
| 162 | return null; |
| 163 | } |
| 164 | |
| 165 | return buffer.toByteArray(); |
| 166 | } |
| 167 | } |