(android)UUIDの取得

gistfile1.java

    private static String uniqueID = null;
    private static final String PREF_UNIQUE_ID = "PREF_UNIQUE_ID";

    public synchronized static String id(Context context) {
        if (uniqueID == null) {
            SharedPreferences sp = context.getSharedPreferences(PREF_UNIQUE_ID,
                    Context.MODE_PRIVATE);
            uniqueID = sp.getString(PREF_UNIQUE_ID, null);
            if (uniqueID == null) {
                uniqueID = UUID.randomUUID().toString();
                Editor editor = sp.edit();
                editor.putString(PREF_UNIQUE_ID, uniqueID);
                editor.commit();
            }
        }
        return uniqueID;
    }