1 /*
   2  * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #warn This file is preprocessed before being compiled
  27 
  28 package sun.util;
  29 
  30 import java.util.Arrays;
  31 import java.util.Collection;
  32 import java.util.Collections;
  33 import java.util.HashSet;
  34 import java.util.List;
  35 import java.util.Locale;
  36 import java.util.ResourceBundle;
  37 import java.util.ResourceBundle.Control;
  38 
  39 /**
  40  * This is a convenient class for loading some of internal resources faster
  41  * if they are built with Resources.gmk defined in J2SE workspace. Also,
  42  * they have to be in class file format.
  43  *
  44  * "LOCALE_LIST" will be replaced at built time by a list of locales we
  45  * defined in Defs.gmk. We want to exclude these locales from search to
  46  * gain better performance. For example, since we know if the resource
  47  * is built with Resources.gmk, they are not going to provide basename_en.class
  48  * & basename_en_US.class resources, in that case, continuing searching them
  49  * is expensive. By excluding them from the candidate locale list, these
  50  * resources won't be searched.
  51  *
  52  * @since 1.6.
  53  */
  54 public class CoreResourceBundleControl extends ResourceBundle.Control {
  55     /* the candidate locale list to search */
  56     private final Collection<Locale> excludedJDKLocales;
  57     /* singlton instance of the resource bundle control. */
  58     private static CoreResourceBundleControl resourceBundleControlInstance =
  59         new CoreResourceBundleControl();
  60 
  61     protected CoreResourceBundleControl() {
  62         excludedJDKLocales = Arrays.asList(#LOCALE_LIST#);
  63     }
  64 
  65     /**
  66      * This method is to provide a customized ResourceBundle.Control to speed
  67      * up the search of resources in JDK.
  68      *
  69      * @return the instance of resource bundle control.
  70      */
  71     public static CoreResourceBundleControl getRBControlInstance() {
  72         return resourceBundleControlInstance;
  73     }
  74 
  75     /**
  76      * This method is to provide a customized ResourceBundle.Control to speed
  77      * up the search of resources in JDK, with the bundle's package name check.
  78      *
  79      * @param bundleName bundle name to check
  80      * @return the instance of resource bundle control if the bundle is JDK's,
  81      *    otherwise returns null.
  82      */
  83     public static CoreResourceBundleControl getRBControlInstance(String bundleName) {
  84         if (bundleName.startsWith("com.sun.") ||
  85             bundleName.startsWith("java.") ||
  86             bundleName.startsWith("javax.") ||
  87             bundleName.startsWith("sun.")) {
  88             return resourceBundleControlInstance;
  89         } else {
  90             return null;
  91         }
  92     }
  93 
  94     /**
  95      * @returns a list of candidate locales to search from.
  96      * @exception NullPointerException if baseName or locale is null.
  97      */
  98     @Override
  99     public List<Locale> getCandidateLocales(String baseName, Locale locale) {
 100         List<Locale> candidates = super.getCandidateLocales(baseName, locale);
 101         candidates.removeAll(excludedJDKLocales);
 102         return candidates;
 103     }
 104 
 105     /**
 106      * @ returns TTL_DONT_CACHE so that ResourceBundle instance won't be cached.
 107      * User of this CoreResourceBundleControl should probably maintain a hard reference
 108      * to the ResourceBundle object themselves.
 109      */
 110     @Override
 111     public long getTimeToLive(String baseName, Locale locale) {
 112         return ResourceBundle.Control.TTL_DONT_CACHE;
 113     }
 114 }