/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.util;


import java.io.InputStream;
import java.util.Locale;
import java.util.Properties;

import org.apache.tomcat.util.ExceptionUtils;
import org.apache.tomcat.util.compat.JreCompat;



Utility class that attempts to map from a Locale to the corresponding
character set to be used for interpreting input text (or generating
output text) when the Content-Type header does not include one.  You
can customize the behavior of this class by modifying the mapping data
it loads, or by subclassing it (to change the algorithm) and then using
your own version for a particular web application.
Author:
Craig R. McClanahan/**
 * Utility class that attempts to map from a Locale to the corresponding
 * character set to be used for interpreting input text (or generating
 * output text) when the Content-Type header does not include one.  You
 * can customize the behavior of this class by modifying the mapping data
 * it loads, or by subclassing it (to change the algorithm) and then using
 * your own version for a particular web application.
 *
 * @author Craig R. McClanahan
 */
public class CharsetMapper {


    // ---------------------------------------------------- Manifest Constants


    
Default properties resource name.
/**
     * Default properties resource name.
     */
    public static final String DEFAULT_RESOURCE =
      "/org/apache/catalina/util/CharsetMapperDefault.properties";


    // ---------------------------------------------------------- Constructors


    
Construct a new CharsetMapper using the default properties resource.
/**
     * Construct a new CharsetMapper using the default properties resource.
     */
    public CharsetMapper() {
        this(DEFAULT_RESOURCE);
    }


    
Construct a new CharsetMapper using the specified properties resource.
Params:
name – Name of a properties resource to be loaded
Throws:
IllegalArgumentException – if the specified properties
 resource could not be loaded for any reason./**
     * Construct a new CharsetMapper using the specified properties resource.
     *
     * @param name Name of a properties resource to be loaded
     *
     * @exception IllegalArgumentException if the specified properties
     *  resource could not be loaded for any reason.
     */
    public CharsetMapper(String name) {
        if (JreCompat.isGraalAvailable()) {
            map.put("en", "ISO-8859-1");
        } else {
            try (InputStream stream = this.getClass().getResourceAsStream(name)) {
                map.load(stream);
            } catch (Throwable t) {
                ExceptionUtils.handleThrowable(t);
                throw new IllegalArgumentException(t);
            }
        }
    }


    // ---------------------------------------------------- Instance Variables


    
The mapping properties that have been initialized from the specified or
default properties resource.
/**
     * The mapping properties that have been initialized from the specified or
     * default properties resource.
     */
    private Properties map = new Properties();


    // ------------------------------------------------------- Public Methods


    
Calculate the name of a character set to be assumed, given the specified
Locale and the absence of a character set specified as part of the
content type header.
Params:
locale – The locale for which to calculate a character set
Returns:
the charset name/**
     * Calculate the name of a character set to be assumed, given the specified
     * Locale and the absence of a character set specified as part of the
     * content type header.
     *
     * @param locale The locale for which to calculate a character set
     * @return the charset name
     */
    public String getCharset(Locale locale) {
        // Match full language_country_variant first, then language_country,
        // then language only
        String charset = map.getProperty(locale.toString());
        if (charset == null) {
            charset = map.getProperty(locale.getLanguage() + "_"
                    + locale.getCountry());
            if (charset == null) {
                charset = map.getProperty(locale.getLanguage());
            }
        }
        return charset;
    }


    
The deployment descriptor can have a
locale-encoding-mapping-list element which describes the
webapp's desired mapping from locale to charset.  This method
gets called when processing the web.xml file for a context
Params:
locale – The locale for a character set
charset – The charset to be associated with the locale/**
     * The deployment descriptor can have a
     * locale-encoding-mapping-list element which describes the
     * webapp's desired mapping from locale to charset.  This method
     * gets called when processing the web.xml file for a context
     *
     * @param locale The locale for a character set
     * @param charset The charset to be associated with the locale
     */
    public void addCharsetMappingFromDeploymentDescriptor(String locale, String charset) {
        map.put(locale, charset);
    }


}