Initial revision

From-SVN: r102074

libjava/classpath/java/util/PropertyResourceBundle.java

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+/* PropertyResourceBundle -- a resource bundle built from a Property file
+   Copyright (C) 1998, 1999, 2001, 2002 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package java.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * This class is a concrete <code>ResourceBundle</code> that gets it
+ * resources from a property file. This implies that the resources are
+ * strings. For more information about resource bundles see the class
+ * <code>ResourceBundle</code>.
+ *
+ * You should not use this class directly, or subclass it, but you get
+ * an object of this class automatically when you call
+ * <code>ResourceBundle.getBundle()</code> and there is a properties
+ * file.
+ *
+ * If there is also a class for this resource and the same locale, the
+ * class will be chosen. The properties file should have the name of the
+ * resource bundle, appended with the locale (e.g. <code>_de</code> and the
+ * extension <code>.properties</code>. The file should have the same format
+ * as for <code>Properties.load()</code>
+ *
+ * An example of a properties file for the german language is given
+ * here. This extends the example given in ListResourceBundle.
+ * Create a file MyResource_de.properties with the following contents
+ * and put it in the CLASSPATH. (The char <code>\u00e4</code> is the
+ * german umlaut)
+ *
+ *
+<pre>
+s1=3
+s2=MeineDisk
+s3=3. M\u00e4rz 96
+s4=Die Diskette ''{1}'' enth\u00e4lt {0} in {2}.
+s5=0
+s6=keine Dateien
+s7=1
+s8=eine Datei
+s9=2
+s10={0,number} Dateien
+s11=Die Formatierung warf eine Exception: {0}
+s12=FEHLER
+s13=Ergebnis
+s14=Dialog
+s15=Auswahlkriterium
+s16=1,3
+</pre>
+ *
+ * @author Jochen Hoenicke
+ * @see ResourceBundle
+ * @see ListResourceBundle
+ * @see Properties#load(InputStream)
+ * @since 1.1
+ * @status updated to 1.4
+ */
+public class PropertyResourceBundle extends ResourceBundle
+{
+  /** The properties file this bundle is based on. */
+  private Properties properties;
+
+  /**
+   * Creates a new property resource bundle.
+   *
+   * @param stream an input stream, where the resources are read from
+   * @throws NullPointerException if stream is null
+   * @throws IOException if reading the stream fails
+   */
+  public PropertyResourceBundle(InputStream stream) throws IOException
+  {
+    properties = new Properties();
+    properties.load(stream);
+  }
+
+  /**
+   * Called by <code>getObject</code> when a resource is needed. This
+   * returns the resource given by the key.
+   *
+   * @param key the key of the resource
+   * @return the resource for the key, or null if it doesn't exist
+   */
+  public Object handleGetObject(String key)
+  {
+    return properties.getProperty(key);
+  }
+
+  /**
+   * This method should return all keys for which a resource exists.
+   *
+   * @return an enumeration of the keys
+   */
+  public Enumeration getKeys()
+  {
+    if (parent == null)
+      return properties.propertyNames();
+    // We make a new Set that holds all the keys, then return an enumeration
+    // for that. This prevents modifications from ruining the enumeration,
+    // as well as ignoring duplicates.
+    Set s = new HashSet();
+    Enumeration e = properties.propertyNames();
+    while (e.hasMoreElements())
+      s.add(e.nextElement());
+    ResourceBundle bundle = parent;
+    // Eliminate tail recursion.
+    do
+      {
+        e = bundle.getKeys();
+        while (e.hasMoreElements())
+          s.add(e.nextElement());
+        bundle = bundle.parent;
+      }
+    while (bundle != null);
+    return Collections.enumeration(s);
+  }
+} // class PropertyResourceBundle