public static NumberFilter deserializeFromFile(Context context) {
try {
FileInputStream fis = context.openFileInput(DIRECTORY_FILE);
NumberFilterStorage storage = NumberFilterStorage.fromStream(fis);
return new NumberFilter(
new BloomFilter(Base64.decode(storage.getFilterData()), storage.getHashCount()));
} catch (IOException ioe) {
Log.w("NumberFilter", ioe);
return new NumberFilter(null);
}
}
private byte[] getZID() {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
if (preferences.contains("ZID")) {
try {
return Base64.decode(preferences.getString("ZID", null));
} catch (IOException e) {
return setZID();
}
} else {
return setZID();
}
}
private byte[] setZID() {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
try {
byte[] zid = new byte[12];
SecureRandom.getInstance("SHA1PRNG").nextBytes(zid);
String encodedZid = Base64.encodeBytes(zid);
preferences.edit().putString("ZID", encodedZid).commit();
return zid;
} catch (NoSuchAlgorithmException e) {
throw new IllegalArgumentException(e);
}
}
public void serializeToFile(Context context) {
if (this.bloomFilter == null) return;
try {
FileOutputStream fout = context.openFileOutput(DIRECTORY_FILE, 0);
String numberFilter = Base64.encodeBytes(bloomFilter.getFilter());
NumberFilterStorage storage =
new NumberFilterStorage(numberFilter, bloomFilter.getHashCount());
storage.serializeToStream(fout);
fout.close();
} catch (IOException ioe) {
Log.w("NumberFilter", ioe);
}
}