001    /*
002     * Copyright 2005-2008 Sun Microsystems, Inc.  All Rights Reserved.
003     * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004     *
005     * This code is free software; you can redistribute it and/or modify it
006     * under the terms of the GNU General Public License version 2 only, as
007     * published by the Free Software Foundation.  Sun designates this
008     * particular file as subject to the "Classpath" exception as provided
009     * by Sun in the LICENSE file that accompanied this code.
010     *
011     * This code is distributed in the hope that it will be useful, but WITHOUT
012     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013     * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
014     * version 2 for more details (a copy is included in the LICENSE file that
015     * accompanied this code).
016     *
017     * You should have received a copy of the GNU General Public License version
018     * 2 along with this work; if not, write to the Free Software Foundation,
019     * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020     *
021     * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022     * CA 95054 USA or visit www.sun.com if you need additional information or
023     * have any questions.
024     */
025    
026    package com.sun.tools.javac.util;
027    
028    import com.sun.tools.javac.api.Messages;
029    import java.lang.ref.SoftReference;
030    import java.util.ResourceBundle;
031    import java.util.MissingResourceException;
032    import java.text.MessageFormat;
033    import java.util.HashMap;
034    import java.util.Locale;
035    import java.util.Map;
036    
037    /**
038     *  Support for formatted localized messages.
039     *
040     *  <p><b>This is NOT part of any API supported by Sun Microsystems.  If
041     *  you write code that depends on this, you do so at your own risk.
042     *  This code and its internal interfaces are subject to change or
043     *  deletion without notice.</b>
044     */
045    public class JavacMessages implements Messages {
046        /** The context key for the JavacMessages object. */
047        protected static final Context.Key<JavacMessages> messagesKey =
048            new Context.Key<JavacMessages>();
049    
050        /** Get the JavacMessages instance for this context. */
051        public static JavacMessages instance(Context context) {
052            JavacMessages instance = context.get(messagesKey);
053            if (instance == null)
054                instance = new JavacMessages(context);
055            return instance;
056        }
057    
058        private Map<Locale, SoftReference<List<ResourceBundle>>> bundleCache;
059    
060        private List<String> bundleNames;
061    
062        private Locale currentLocale;
063        private List<ResourceBundle> currentBundles;
064    
065        public Locale getCurrentLocale() {
066            return currentLocale;
067        }
068    
069        public void setCurrentLocale(Locale locale) {
070            if (locale == null) {
071                locale = Locale.getDefault();
072            }
073            this.currentBundles = getBundles(locale);
074            this.currentLocale = locale;
075        }
076    
077        /** Creates a JavacMessages object.
078         */
079        public JavacMessages(Context context) {
080            this(defaultBundleName);
081            context.put(messagesKey, this);
082        }
083    
084        /** Creates a JavacMessages object.
085         * @param bundleName the name to identify the resource buundle of localized messages.
086         */
087        public JavacMessages(String bundleName) throws MissingResourceException {
088            bundleNames = List.nil();
089            bundleCache = new HashMap<Locale, SoftReference<List<ResourceBundle>>>();
090            add(bundleName);
091            setCurrentLocale(Locale.getDefault());
092        }
093    
094        public JavacMessages() throws MissingResourceException {
095            this(defaultBundleName);
096        }
097    
098        public void add(String bundleName) throws MissingResourceException {
099            bundleNames = bundleNames.prepend(bundleName);
100            if (!bundleCache.isEmpty())
101                bundleCache.clear();
102            currentBundles = null;
103        }
104    
105        public List<ResourceBundle> getBundles(Locale locale) {
106            if (locale == currentLocale && currentBundles != null)
107                return currentBundles;
108            SoftReference<List<ResourceBundle>> bundles = bundleCache.get(locale);
109            List<ResourceBundle> bundleList = bundles == null ? null : bundles.get();
110            if (bundleList == null) {
111                bundleList = List.nil();
112                for (String bundleName : bundleNames) {
113                    try {
114                        ResourceBundle rb = ResourceBundle.getBundle(bundleName, locale);
115                        bundleList = bundleList.prepend(rb);
116                    } catch (MissingResourceException e) {
117                        throw new InternalError("Cannot find javac resource bundle for locale " + locale);
118                    }
119                }
120                bundleCache.put(locale, new SoftReference<List<ResourceBundle>>(bundleList));
121            }
122            return bundleList;
123        }
124    
125        /** Gets the localized string corresponding to a key, formatted with a set of args.
126         */
127        public String getLocalizedString(String key, Object... args) {
128            return getLocalizedString(currentLocale, key, args);
129        }
130    
131        public String getLocalizedString(Locale l, String key, Object... args) {
132            if (l == null)
133                l = getCurrentLocale();
134            return getLocalizedString(getBundles(l), key, args);
135        }
136    
137        /* Static access:
138         * javac has a firmly entrenched notion of a default message bundle
139         * which it can access from any static context. This is used to get
140         * easy access to simple localized strings.
141         */
142    
143        private static final String defaultBundleName =
144            "com.sun.tools.javac.resources.compiler";
145        private static ResourceBundle defaultBundle;
146        private static JavacMessages defaultMessages;
147    
148    
149        /**
150         * Gets a localized string from the compiler's default bundle.
151         */
152        // used to support legacy Log.getLocalizedString
153        static String getDefaultLocalizedString(String key, Object... args) {
154            return getLocalizedString(List.of(getDefaultBundle()), key, args);
155        }
156    
157        // used to support legacy static Diagnostic.fragment
158        @Deprecated
159        static JavacMessages getDefaultMessages() {
160            if (defaultMessages == null)
161                defaultMessages = new JavacMessages(defaultBundleName);
162            return defaultMessages;
163        }
164    
165        public static ResourceBundle getDefaultBundle() {
166            try {
167                if (defaultBundle == null)
168                    defaultBundle = ResourceBundle.getBundle(defaultBundleName);
169                return defaultBundle;
170            }
171            catch (MissingResourceException e) {
172                throw new Error("Fatal: Resource for compiler is missing", e);
173            }
174        }
175    
176        private static String getLocalizedString(List<ResourceBundle> bundles,
177                                                 String key,
178                                                 Object... args) {
179           String msg = null;
180            for (List<ResourceBundle> l = bundles; l.nonEmpty() && msg == null; l = l.tail) {
181                ResourceBundle rb = l.head;
182                try {
183                    msg = rb.getString(key);
184                }
185                catch (MissingResourceException e) {
186                    // ignore, try other bundles in list
187                }
188            }
189            if (msg == null) {
190                msg = "compiler message file broken: key=" + key +
191                    " arguments={0}, {1}, {2}, {3}, {4}, {5}, {6}, {7}";
192            }
193            return MessageFormat.format(msg, args);
194        }
195    }