001: /*
002: * Copyright 1999,2004 The Apache Software Foundation.
003: *
004: * Licensed under the Apache License, Version 2.0 (the "License");
005: * you may not use this file except in compliance with the License.
006: * You may obtain a copy of the License at
007: *
008: * http://www.apache.org/licenses/LICENSE-2.0
009: *
010: * Unless required by applicable law or agreed to in writing, software
011: * distributed under the License is distributed on an "AS IS" BASIS,
012: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013: * See the License for the specific language governing permissions and
014: * limitations under the License.
015: */
016:
017: /*
018: * This class is based on a class originally written by Jason Hunter
019: * <jhunter@acm.org> as part of the book "Java Servlet Programming"
020: * (O'Reilly). See http://www.servlets.com/book for more information.
021: * Used by Sun Microsystems with permission.
022: */
023:
024: package org.apache.catalina.util;
025:
026: import java.io.InputStream;
027: import java.util.Locale;
028: import java.util.Properties;
029:
030: /**
031: * Utility class that attempts to map from a Locale to the corresponding
032: * character set to be used for interpreting input text (or generating
033: * output text) when the Content-Type header does not include one. You
034: * can customize the behavior of this class by modifying the mapping data
035: * it loads, or by subclassing it (to change the algorithm) and then using
036: * your own version for a particular web application.
037: *
038: * @author Craig R. McClanahan
039: * @revision $Date: 2004/02/27 14:58:50 $ $Version$
040: */
041:
042: public class CharsetMapper {
043:
044: // ---------------------------------------------------- Manifest Constants
045:
046: /**
047: * Default properties resource name.
048: */
049: public static final String DEFAULT_RESOURCE = "/org/apache/catalina/util/CharsetMapperDefault.properties";
050:
051: // ---------------------------------------------------------- Constructors
052:
053: /**
054: * Construct a new CharsetMapper using the default properties resource.
055: */
056: public CharsetMapper() {
057:
058: this (DEFAULT_RESOURCE);
059:
060: }
061:
062: /**
063: * Construct a new CharsetMapper using the specified properties resource.
064: *
065: * @param name Name of a properties resource to be loaded
066: *
067: * @exception IllegalArgumentException if the specified properties
068: * resource could not be loaded for any reason.
069: */
070: public CharsetMapper(String name) {
071:
072: try {
073: InputStream stream = this .getClass().getResourceAsStream(
074: name);
075: map.load(stream);
076: stream.close();
077: } catch (Throwable t) {
078: throw new IllegalArgumentException(t.toString());
079: }
080:
081: }
082:
083: // ---------------------------------------------------- Instance Variables
084:
085: /**
086: * The mapping properties that have been initialized from the specified or
087: * default properties resource.
088: */
089: private Properties map = new Properties();
090:
091: // ------------------------------------------------------- Public Methods
092:
093: /**
094: * Calculate the name of a character set to be assumed, given the specified
095: * Locale and the absence of a character set specified as part of the
096: * content type header.
097: *
098: * @param locale The locale for which to calculate a character set
099: */
100: public String getCharset(Locale locale) {
101:
102: String charset = null;
103:
104: // First, try a full name match (language and country)
105: charset = map.getProperty(locale.toString());
106: if (charset != null)
107: return (charset);
108:
109: // Second, try to match just the language
110: charset = map.getProperty(locale.getLanguage());
111: return (charset);
112:
113: }
114:
115: /**
116: * The deployment descriptor can have a
117: * locale-encoding-mapping-list element which describes the
118: * webapp's desired mapping from locale to charset. This method
119: * gets called when processing the web.xml file for a context
120: *
121: * @param locale The locale for a character set
122: * @param charset The charset to be associated with the locale
123: */
124: public void addCharsetMappingFromDeploymentDescriptor(
125: String locale, String charset) {
126: map.put(locale, charset);
127: }
128:
129: }
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