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 android.nfc.tech;
18 
19 import android.nfc.ErrorCodes;
20 import android.nfc.FormatException;
21 import android.nfc.INfcTag;
22 import android.nfc.NdefMessage;
23 import android.nfc.Tag;
24 import android.nfc.TagLostException;
25 import android.os.RemoteException;
26 import android.util.Log;
27 
28 import java.io.IOException;
29 
30 /**
31  * Provide access to NDEF format operations on a {@link Tag}.
32  *
33  * <p>Acquire a {@link NdefFormatable} object using {@link #get}.
34  *
35  * <p>Android devices with NFC must only enumerate and implement this
36  * class for tags for which it can format to NDEF.
37  *
38  * <p>Unfortunately the procedures to convert unformated tags to NDEF formatted
39  * tags are not specified by NFC Forum, and are not generally well-known. So
40  * there is no mandatory set of tags for which all Android devices with NFC
41  * must support {@link NdefFormatable}.
42  *
43  * <p class="note"><strong>Note:</strong> Methods that perform I/O operations
44  * require the {@link android.Manifest.permission#NFC} permission.
45  */
46 public final class NdefFormatable extends BasicTagTechnology {
47     private static final String TAG = "NFC";
48 
49     /**
50      * Get an instance of {@link NdefFormatable} for the given tag.
51      * <p>Does not cause any RF activity and does not block.
52      * <p>Returns null if {@link NdefFormatable} was not enumerated in {@link Tag#getTechList}.
53      * This indicates the tag is not NDEF formatable by this Android device.
54      *
55      * @param tag an NDEF formatable tag
56      * @return NDEF formatable object
57      */
get(Tag tag)58     public static NdefFormatable get(Tag tag) {
59         if (!tag.hasTech(TagTechnology.NDEF_FORMATABLE)) return null;
60         try {
61             return new NdefFormatable(tag);
62         } catch (RemoteException e) {
63             return null;
64         }
65     }
66 
67     /**
68      * Internal constructor, to be used by NfcAdapter
69      * @hide
70      */
NdefFormatable(Tag tag)71     public NdefFormatable(Tag tag) throws RemoteException {
72         super(tag, TagTechnology.NDEF_FORMATABLE);
73     }
74 
75     /**
76      * Format a tag as NDEF, and write a {@link NdefMessage}.
77      *
78      * <p>This is a multi-step process, an IOException is thrown
79      * if any one step fails.
80      * <p>The card is left in a read-write state after this operation.
81      *
82      * <p>This is an I/O operation and will block until complete. It must
83      * not be called from the main application thread. A blocked call will be canceled with
84      * {@link IOException} if {@link #close} is called from another thread.
85      *
86      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
87      *
88      * @param firstMessage the NDEF message to write after formatting, can be null
89      * @throws TagLostException if the tag leaves the field
90      * @throws IOException if there is an I/O failure, or the operation is canceled
91      * @throws FormatException if the NDEF Message to write is malformed
92      */
format(NdefMessage firstMessage)93     public void format(NdefMessage firstMessage) throws IOException, FormatException {
94         format(firstMessage, false);
95     }
96 
97     /**
98      * Formats a tag as NDEF, write a {@link NdefMessage}, and make read-only.
99      *
100      * <p>This is a multi-step process, an IOException is thrown
101      * if any one step fails.
102      * <p>The card is left in a read-only state if this method returns successfully.
103      *
104      * <p>This is an I/O operation and will block until complete. It must
105      * not be called from the main application thread. A blocked call will be canceled with
106      * {@link IOException} if {@link #close} is called from another thread.
107      *
108      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
109      *
110      * @param firstMessage the NDEF message to write after formatting
111      * @throws TagLostException if the tag leaves the field
112      * @throws IOException if there is an I/O failure, or the operation is canceled
113      * @throws FormatException if the NDEF Message to write is malformed
114      * @throws SecurityException if the tag object is reused after the tag has left the field
115      */
formatReadOnly(NdefMessage firstMessage)116     public void formatReadOnly(NdefMessage firstMessage) throws IOException, FormatException {
117         format(firstMessage, true);
118     }
119 
format(NdefMessage firstMessage, boolean makeReadOnly)120     /*package*/ void format(NdefMessage firstMessage, boolean makeReadOnly) throws IOException,
121             FormatException {
122         checkConnected();
123 
124         try {
125             int serviceHandle = mTag.getServiceHandle();
126             INfcTag tagService = mTag.getTagService();
127             if (tagService == null) {
128                 throw new IOException();
129             }
130             int errorCode = tagService.formatNdef(serviceHandle, MifareClassic.KEY_DEFAULT);
131             switch (errorCode) {
132                 case ErrorCodes.SUCCESS:
133                     break;
134                 case ErrorCodes.ERROR_IO:
135                     throw new IOException();
136                 case ErrorCodes.ERROR_INVALID_PARAM:
137                     throw new FormatException();
138                 default:
139                     // Should not happen
140                     throw new IOException();
141             }
142             // Now check and see if the format worked
143             if (!tagService.isNdef(serviceHandle)) {
144                 throw new IOException();
145             }
146 
147             // Write a message, if one was provided
148             if (firstMessage != null) {
149                 errorCode = tagService.ndefWrite(serviceHandle, firstMessage);
150                 switch (errorCode) {
151                     case ErrorCodes.SUCCESS:
152                         break;
153                     case ErrorCodes.ERROR_IO:
154                         throw new IOException();
155                     case ErrorCodes.ERROR_INVALID_PARAM:
156                         throw new FormatException();
157                     default:
158                         // Should not happen
159                         throw new IOException();
160                 }
161             }
162 
163             // optionally make read-only
164             if (makeReadOnly) {
165                 errorCode = tagService.ndefMakeReadOnly(serviceHandle);
166                 switch (errorCode) {
167                     case ErrorCodes.SUCCESS:
168                         break;
169                     case ErrorCodes.ERROR_IO:
170                         throw new IOException();
171                     case ErrorCodes.ERROR_INVALID_PARAM:
172                         throw new IOException();
173                     default:
174                         // Should not happen
175                         throw new IOException();
176                 }
177             }
178         } catch (RemoteException e) {
179             Log.e(TAG, "NFC service dead", e);
180         }
181     }
182 }
183