1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 package org.chromium.chrome.browser.identity; 6 7 import android.content.Context; 8 import android.content.SharedPreferences; 9 import android.preference.PreferenceManager; 10 11 import com.google.common.annotations.VisibleForTesting; 12 13 import java.util.UUID; 14 15 import javax.annotation.Nullable; 16 17 /** 18 * Generates unique IDs that are {@link UUID} strings. 19 */ 20 public class UuidBasedUniqueIdentificationGenerator implements UniqueIdentificationGenerator { 21 public static final String GENERATOR_ID = "UUID"; 22 private final Context mContext; 23 private final String mPreferenceKey; 24 25 public UuidBasedUniqueIdentificationGenerator(Context context, String preferenceKey) { 26 mContext = context; 27 mPreferenceKey = preferenceKey; 28 } 29 30 @Override 31 public String getUniqueId(@Nullable String salt) { 32 SharedPreferences preferences = PreferenceManager 33 .getDefaultSharedPreferences(mContext); 34 String storedUniqueId = preferences.getString(mPreferenceKey, null); 35 if (storedUniqueId != null) { 36 return storedUniqueId; 37 } 38 39 // Generate a new unique ID. 40 String uniqueId = getUUID(); 41 42 // Store the field so we ensure we always return the same unique ID. 43 SharedPreferences.Editor editor = preferences.edit(); 44 editor.putString(mPreferenceKey, uniqueId); 45 editor.apply(); 46 return uniqueId; 47 48 } 49 50 @VisibleForTesting 51 String getUUID() { 52 return UUID.randomUUID().toString(); 53 } 54 } 55
