/*
* $Id: MessagesMap.java 471754 2006-11-06 14:55:09Z husted $
*
* 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.struts.faces.util;
import java.util.Collection;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import org.apache.struts.util.MessageResources;
/**
* <p>A limited immutable <code>Map</code> implementation that wraps the
* <code>MessageResources</code> instance for the specified
* <code>Locale</code>. Exposing the messages as a <code>Map</code>
* makes them easily accessible via value binding expressions, as
* well as JSP 2.0 expression language expressions.
*/
public class MessagesMap implements Map {
// ------------------------------------------------------------ Constructors
/**
* <p>Construct a new {@link MessagesMap} instance that wraps the
* specified <code>MessageResources</code> instance, and returns messages
* for the specified <code>Locale</code>.</p>
*
* @param messages <code>MessageResources</code> instance to wrap
* @param locale <code>Locale</code> for which to retrieve messages,
* or <code>null</code> for the system default <code>Locale</code>
*
* @exception NullPointerException if <code>messages</code>
* is <code>null</code>
*/
public MessagesMap(MessageResources messages, Locale locale) {
super();
if (messages == null) {
throw new NullPointerException();
}
this.messages = messages;
this.locale = locale;
}
// ------------------------------------------------------ Instance Variables
/**
* <p>The <code>Locale</code> for which to return messages, or
* <code>null</code> for the system default <code>Locale</code>.</p>
*/
private Locale locale = null;
/**
* <p>The <code>MessageResources</code> being wrapped by this
* {@link MessagesMap}.</p>
*/
private MessageResources messages = null;
// ---------------------------------------------------------- Public Methods
/**
* <p>The <code>clear()</code> method is not supported.</p>
*/
public void clear() {
throw new UnsupportedOperationException();
}
/**
* <p>Return <code>true</code> if there is a message for the
* specified key.</p>
*
* @param key Message key to evaluate
*/
public boolean containsKey(Object key) {
if (key == null) {
return (false);
} else {
return (messages.isPresent(locale, key.toString()));
}
}
/**
* <p>The <code>containsValue()</code> method is not supported.</p>
*
* @param value Value to evaluate
*/
public boolean containsValue(Object value) {
throw new UnsupportedOperationException();
}
/**
* <p>The <code>entrySet()</code> method is not supported.</p>
*/
public Set entrySet() {
throw new UnsupportedOperationException();
}
/**
* <p>The <code>equals</code> method checks whether equal
* <code>MessageResources</code> and <code>Locale</code> are
* being wrapped.</p>
*
* @param o The object to be compared
*/
public boolean equals(Object o) {
if (!(o instanceof MessagesMap)) {
return (false);
}
MessagesMap other = (MessagesMap) o;
if (!messages.equals(other.getMessages())) {
return (false);
}
if (locale == null) {
return (other.getLocale() == null);
} else {
return (locale.equals(other.getLocale()));
}
}
/**
* <p>Return the message string for the specified key.</p>
*
* @param key Key for message to return
*/
public Object get(Object key) {
if (key == null) {
return ("??????");
} else {
return (messages.getMessage(locale, key.toString()));
}
}
/**
* <p>The <code>hashCode()</code> method returns values that will
* be identical if the <code>equals</code> method returns <code>true</code>.
* </p>
*/
public int hashCode() {
int value = messages.hashCode();
if (locale != null) {
value = value ^ locale.hashCode();
}
return (value);
}
/**
* <p>The <code>isEmpty()</code> method returns <code>false</code>, on the
* assumption that there is always at least one message available.</p>
*/
public boolean isEmpty() {
return (false);
}
/**
* <p>The <code>keySet()</code> method is not supported.</p>
*/
public Set keySet() {
throw new UnsupportedOperationException();
}
/**
* <p>The <code>put()</code> method is not supported.</p>
*
* @param key Key to store
* @param value Value to store
*/
public Object put(Object key, Object value) {
throw new UnsupportedOperationException();
}
/**
* <p>The <code>putAll()</code> method is not supported.</p>
*
* @param map Keys and values to store
*/
public void putAll(Map map) {
throw new UnsupportedOperationException();
}
/**
* <p>The <code>remove()</code> method is not supported.</p>
*
* @param key Key to remove
*/
public Object remove(Object key) {
throw new UnsupportedOperationException();
}
/**
* <p>The <code>size()</code> method is not supported.</p>
*/
public int size() {
throw new UnsupportedOperationException();
}
/**
* <p>The <code>values()</code> method is not supported.</p>
*/
public Collection values() {
throw new UnsupportedOperationException();
}
// --------------------------------------------------------- Package Methods
/**
* <p>Return the <code>Locale</code> we object we are wrapping.</p>
*/
Locale getLocale() {
return (this.locale);
}
/**
* <p>Return the <code>MessageResources</code> object we are wrapping.</p>
*/
MessageResources getMessages() {
return (this.messages);
}
}