tapestry/tapestry-framework/src/java/org/apache/tapestry/util/text/LocalizedProperties.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed 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.tapestry.util.text;

import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.HashMap;
import java.util.Map;

/**
 * A version of java.util.Properties that can read the properties from files
 * using an encoding other than ISO-8859-1. All non-latin characters are read
 * correctly using the given encoding and no longer need to be quoted using
 * native2ascii. In addition, the properties may be stored in an arbitrary map,
 * rather than only in Properties. For example, using LinkedHashMap will
 * preserve the order of the properties as defined in the file.
 * 
 * @author mb
 * @since 4.0
 */
public class LocalizedProperties
{

    private Map _propertyMap;

    /**
     * Create a new object with an empty property storage.
     */
    public LocalizedProperties()
    {
        this(new HashMap());
    }

    /**
     * Use the provided argument as the storage location for the properties
     * managed by this object. This allows different types of Map
     * implementations to be used, such as a LinkedHashMap to preserve the order
     * of the keys, for example. The provided map may contain the default
     * property values as well.
     * 
     * @param propertyMap
     *            the map where properties are to be stored
     */
    public LocalizedProperties(Map propertyMap)
    {
        _propertyMap = propertyMap;
    }

    /**
     * Returns the property value corresponding the provided key. If there is no
     * such property, or the value in the provided map is not of type String,
     * null is returned.
     * 
     * @param key
     *            the property key
     * @return the value of the property, or null if there is no such property
     */
    public String getProperty(String key)
    {
        Object value = _propertyMap.get(key);
        if (value instanceof String) return (String) value;
        return null;
    }

    /**
     * Returns the property value corresponding to the provided key, or the
     * provided default value if no such property exists.
     * 
     * @param key
     *            the property key
     * @param defaultValue
     *            the default value of the property
     * @return the value of the property, or the default value if there is no
     *         such property
     */
    public String getProperty(String key, String defaultValue)
    {
        String value = getProperty(key);
        if (value != null) return value;
        return defaultValue;
    }

    /**
     * Stores a property value.
     * 
     * @param key
     *            the property key
     * @param value
     *            the property value
     */
    public void setProperty(String key, String value)
    {
        _propertyMap.put(key, value);
    }

    /**
     * Returns the map containing all properties. The map can be used to
     * enumerate the properties or their keys.
     * 
     * @return a map containing the properties
     */
    public Map getPropertyMap()
    {
        return _propertyMap;
    }

    /**
     * Loads the properties from the given stream using the default character
     * encoding. This method operates in the same way as the equivalent method
     * in {@link java.util.Properties}, but it also handles non-ascii symbols.
     * 
     * @param ins
     *            the stream to load the properties from
     * @throws IOException
     */
    public void load(InputStream ins)
        throws IOException
    {
        LocalizedPropertiesLoader loader = new LocalizedPropertiesLoader(ins);
        loader.load(_propertyMap);
    }

    /**
     * Loads the properties from the given stream using the provided character
     * encoding. This method operates in the same way as the equivalent method
     * in {@link java.util.Properties}, but it also handles non-ascii symbols.
     * 
     * @param ins
     *            the stream to load the properties from
     * @param encoding
     *            the encoding the use when parsing the stream
     * @throws IOException
     */
    public void load(InputStream ins, String encoding)
        throws IOException
    {
        LocalizedPropertiesLoader loader = new LocalizedPropertiesLoader(ins,
                encoding);
        loader.load(_propertyMap);
    }

    /**
     * Loads the properties from the given reader. This method operates in the
     * same way as the equivalent method in {@link java.util.Properties}, but
     * it also handles non-ascii symbols.
     * 
     * @param reader
     *            the reader to load the properties from
     * @throws IOException
     */
    public void load(Reader reader)
        throws IOException
    {
        LocalizedPropertiesLoader loader = new LocalizedPropertiesLoader(reader);
        loader.load(_propertyMap);
    }
}