【Android】设备标识

 1 public class Installation {
 2     private static String sID = null;
 3     private static final String INSTALLATION = "INSTALLATION";
 4 
 5     public synchronized static String id(Context context) {
 6         if (sID == null) {
 7             File installation = new File(context.getFilesDir(), INSTALLATION);
 8             try {
 9                 if (!installation.exists())
10                 writeInstallationFile(installation);
11                 sID = readInstallationFile(installation);
12             } catch (Exception e) {
13                 throw new RuntimeException(e);
14             }
15         }
16         return sID;
17     }
18 
19     private static String readInstallationFile(File installation) throws IOException {
20         RandomAccessFile f = new RandomAccessFile(installation, "r");
21         byte[] bytes = new byte[(int) f.length()];
22         f.readFully(bytes);
23         f.close();
24         return new String(bytes);
25     }
26 
27     private static void writeInstallationFile(File installation) throws IOException {
28         FileOutputStream out = new FileOutputStream(installation);
29         String id = UUID.randomUUID().toString();
30         out.write(id.getBytes());
31         out.close();
32     }
33 }

 1 import android.content.Context;
 2 import android.content.SharedPreferences;
 3 import android.provider.Settings.Secure;
 4 import android.telephony.TelephonyManager;
 5 
 6 import java.io.UnsupportedEncodingException;
 7 import java.util.UUID;
 8 
 9 public class DeviceUuidFactory {
10     protected static final String PREFS_FILE = "device_id.xml";
11     protected static final String PREFS_DEVICE_ID = "device_id";
12 
13     protected static UUID uuid;
14 
15     /**
16     * Returns a unique UUID for the current android device. As with all UUIDs, this unique ID is "very highly likely"
17     * to be unique across all Android devices. Much more so than ANDROID_ID is.
18     *
19     * The UUID is generated by using ANDROID_ID as the base key if appropriate, falling back on
20     * TelephonyManager.getDeviceID() if ANDROID_ID is known to be incorrect, and finally falling back
21     * on a random UUID that‘s persisted to SharedPreferences if getDeviceID() does not return a
22     * usable value.
23     *
24     * In some rare circumstances, this ID may change. In particular, if the device is factory reset a new device ID
25     * may be generated. In addition, if a user upgrades their phone from certain buggy implementations of Android 2.2
26     * to a newer, non-buggy version of Android, the device ID may change. Or, if a user uninstalls your app on
27     * a device that has neither a proper Android ID nor a Device ID, this ID may change on reinstallation.
28     *
29     * Note that if the code falls back on using TelephonyManager.getDeviceId(), the resulting ID will NOT
30     * change after a factory reset. Something to be aware of.
31     *
32     * Works around a bug in Android 2.2 for many devices when using ANDROID_ID directly.
33     *
34     * @see http://code.google.com/p/android/issues/detail?id=10603
35     *
36     * @return a UUID that may be used to uniquely identify your device for most purposes.
37     */
38     public DeviceUuidFactory(Context context) {
39         if( uuid ==null ) {
40             synchronized (DeviceUuidFactory.class) {
41                 if( uuid == null) {
42                     final SharedPreferences prefs = context.getSharedPreferences(PREFS_FILE, 0);
43                     final String id = prefs.getString(PREFS_DEVICE_ID, null );
44 
45                     if (id != null) {
46                         // Use the ids previously computed and stored in the prefs file
47                         uuid = id;
48                     } else {
49                         final String androidId = Secure.getString(context.getContentResolver(), Secure.ANDROID_ID);
50 
51                         // Use the Android ID unless it‘s broken, in which case fallback on deviceId,
52                         // unless it‘s not available, then fallback on a random number which we store
53                         // to a prefs file
54                         try {
55                             if (!"9774d56d682e549c".equals(androidId)) {
56                                 uuid = UUID.nameUUIDFromBytes(androidId.getBytes("utf8"));
57                             } else {
58                                 final String deviceId = ((TelephonyManager) context.getSystemService( Context.TELEPHONY_SERVICE )).getDeviceId();
59                                 uuid = deviceId != null ? UUID.nameUUIDFromBytes(deviceId.getBytes("utf8")) : UUID.randomUUID();
60                             }
61                         } catch (UnsupportedEncodingException e) {
62                             throw new RuntimeException(e);
63                         }
64 
65                         // Write the value out to the prefs file
66                         prefs.edit().putString(PREFS_DEVICE_ID, uuid.toString()).commit();
67 
68                     }
69                 }
70             }
71         }
72     }
73 }