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1   /*
2    * Copyright (c) 2005, 2013, 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  package com.sun.tools.javac.util;
27  
28  import com.sun.tools.javac.api.Messages;
29  import java.lang.ref.SoftReference;
30  import java.util.ResourceBundle;
31  import java.util.MissingResourceException;
32  import java.text.MessageFormat;
33  import java.util.HashMap;
34  import java.util.Locale;
35  import java.util.Map;
36  
37  /**
38   *  Support for formatted localized messages.
39   *
40   *  <p><b>This is NOT part of any supported API.
41   *  If you write code that depends on this, you do so at your own risk.
42   *  This code and its internal interfaces are subject to change or
43   *  deletion without notice.</b>
44   */
45  public class JavacMessages implements Messages {
46      /** The context key for the JavacMessages object. */
47      public static final Context.Key<JavacMessages> messagesKey =
48          new Context.Key<JavacMessages>();
49  
50      /** Get the JavacMessages instance for this context. */
51      public static JavacMessages instance(Context context) {
52          JavacMessages instance = context.get(messagesKey);
53          if (instance == null)
54              instance = new JavacMessages(context);
55          return instance;
56      }
57  
58      private Map<Locale, SoftReference<List<ResourceBundle>>> bundleCache;
59  
60      private List<String> bundleNames;
61  
62      private Locale currentLocale;
63      private List<ResourceBundle> currentBundles;
64  
65      public Locale getCurrentLocale() {
66          return currentLocale;
67      }
68  
69      public void setCurrentLocale(Locale locale) {
70          if (locale == null) {
71              locale = Locale.getDefault();
72          }
73          this.currentBundles = getBundles(locale);
74          this.currentLocale = locale;
75      }
76  
77      /** Creates a JavacMessages object.
78       */
79      public JavacMessages(Context context) {
80          this(defaultBundleName, context.get(Locale.class));
81          context.put(messagesKey, this);
82      }
83  
84      /** Creates a JavacMessages object.
85       * @param bundleName the name to identify the resource bundle of localized messages.
86       */
87      public JavacMessages(String bundleName) throws MissingResourceException {
88          this(bundleName, null);
89      }
90  
91      /** Creates a JavacMessages object.
92       * @param bundleName the name to identify the resource bundle of localized messages.
93       */
94      public JavacMessages(String bundleName, Locale locale) throws MissingResourceException {
95          bundleNames = List.nil();
96          bundleCache = new HashMap<Locale, SoftReference<List<ResourceBundle>>>();
97          add(bundleName);
98          setCurrentLocale(locale);
99      }
100 
101     public JavacMessages() throws MissingResourceException {
102         this(defaultBundleName);
103     }
104 
105     public void add(String bundleName) throws MissingResourceException {
106         bundleNames = bundleNames.prepend(bundleName);
107         if (!bundleCache.isEmpty())
108             bundleCache.clear();
109         currentBundles = null;
110     }
111 
112     public List<ResourceBundle> getBundles(Locale locale) {
113         if (locale == currentLocale && currentBundles != null)
114             return currentBundles;
115         SoftReference<List<ResourceBundle>> bundles = bundleCache.get(locale);
116         List<ResourceBundle> bundleList = bundles == null ? null : bundles.get();
117         if (bundleList == null) {
118             bundleList = List.nil();
119             for (String bundleName : bundleNames) {
120                 try {
121                     ResourceBundle rb = ResourceBundle.getBundle(bundleName, locale);
122                     bundleList = bundleList.prepend(rb);
123                 } catch (MissingResourceException e) {
124                     throw new InternalError("Cannot find javac resource bundle for locale " + locale);
125                 }
126             }
127             bundleCache.put(locale, new SoftReference<List<ResourceBundle>>(bundleList));
128         }
129         return bundleList;
130     }
131 
132     /** Gets the localized string corresponding to a key, formatted with a set of args.
133      */
134     public String getLocalizedString(String key, Object... args) {
135         return getLocalizedString(currentLocale, key, args);
136     }
137 
138     public String getLocalizedString(Locale l, String key, Object... args) {
139         if (l == null)
140             l = getCurrentLocale();
141         return getLocalizedString(getBundles(l), key, args);
142     }
143 
144     /* Static access:
145      * javac has a firmly entrenched notion of a default message bundle
146      * which it can access from any static context. This is used to get
147      * easy access to simple localized strings.
148      */
149 
150     private static final String defaultBundleName =
151         "com.sun.tools.javac.resources.compiler";
152     private static ResourceBundle defaultBundle;
153     private static JavacMessages defaultMessages;
154 
155 
156     /**
157      * Gets a localized string from the compiler's default bundle.
158      */
159     // used to support legacy Log.getLocalizedString
160     static String getDefaultLocalizedString(String key, Object... args) {
161         return getLocalizedString(List.of(getDefaultBundle()), key, args);
162     }
163 
164     // used to support legacy static Diagnostic.fragment
165     @Deprecated
166     static JavacMessages getDefaultMessages() {
167         if (defaultMessages == null)
168             defaultMessages = new JavacMessages(defaultBundleName);
169         return defaultMessages;
170     }
171 
172     public static ResourceBundle getDefaultBundle() {
173         try {
174             if (defaultBundle == null)
175                 defaultBundle = ResourceBundle.getBundle(defaultBundleName);
176             return defaultBundle;
177         }
178         catch (MissingResourceException e) {
179             throw new Error("Fatal: Resource for compiler is missing", e);
180         }
181     }
182 
183     private static String getLocalizedString(List<ResourceBundle> bundles,
184                                              String key,
185                                              Object... args) {
186        String msg = null;
187        for (List<ResourceBundle> l = bundles; l.nonEmpty() && msg == null; l = l.tail) {
188            ResourceBundle rb = l.head;
189            try {
190                msg = rb.getString(key);
191            }
192            catch (MissingResourceException e) {
193                // ignore, try other bundles in list
194            }
195        }
196        if (msg == null) {
197            msg = "compiler message file broken: key=" + key +
198                " arguments={0}, {1}, {2}, {3}, {4}, {5}, {6}, {7}";
199        }
200        return MessageFormat.format(msg, args);
201     }
202 }