首先許可權

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_SETTINGS" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />

程式碼：

public class Installation {
private static 
 
String sID = null;
private static final String INSTALLATION = "INSTALLATION";
public synchronized static String id(Context context) {
if (sID == null) {
File installation = new File(context.getFilesDir(), INSTALLATION);
try {
if (!installation.exists())
writeInstallationFile(installation);
sID = readInstallationFile(
 
installation);
            } catch (Exception e) {
throw new RuntimeException(e);
            }
        }
return sID;
    }
private static String readInstallationFile(File installation) throws IOException {
RandomAccessFile f = new RandomAccessFile(installation, "r");
byte[] bytes = new byte[(int) f.
 
length()];
f.readFully(bytes);
f.close();
return new String(bytes);
    }
private static void writeInstallationFile(File installation) throws IOException {
FileOutputStream out = new FileOutputStream(installation);
String id = UUID.randomUUID().toString();
out.write(id.getBytes());
out.close();
    }
}