/*
* $Id$
*
* 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.struts2.dispatcher;
import javax.servlet.ServletContext;
import java.io.Serializable;
import java.util.AbstractMap;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* A simple implementation of the {@link java.util.Map} interface to handle a collection of attributes and
* init parameters in a {@link javax.servlet.ServletContext} object. The {@link #entrySet()} method
* enumerates over all servlet context attributes and init parameters and returns a collection of both.
* Note, this will occur lazily - only when the entry set is asked for.
*/
public class ApplicationMap extends AbstractMap implements Serializable {
private static final long serialVersionUID = 9136809763083228202L;
private ServletContext context;
private Set<Object> entries;
/**
* Creates a new map object given the servlet context.
*
* @param ctx the servlet context
*/
public ApplicationMap(ServletContext ctx) {
this.context = ctx;
}
/**
* Removes all entries from the Map and removes all attributes from the servlet context.
*/
public void clear() {
entries = null;
Enumeration e = context.getAttributeNames();
while (e.hasMoreElements()) {
context.removeAttribute(e.nextElement().toString());
}
}
/**
* Creates a Set of all servlet context attributes as well as context init parameters.
*
* @return a Set of all servlet context attributes as well as context init parameters.
*/
public Set entrySet() {
if (entries == null) {
entries = new HashSet<Object>();
// Add servlet context attributes
Enumeration enumeration = context.getAttributeNames();
while (enumeration.hasMoreElements()) {
final String key = enumeration.nextElement().toString();
final Object value = context.getAttribute(key);
entries.add(new Map.Entry() {
public boolean equals(Object obj) {
if (!(obj instanceof Map.Entry)) {
return false;
}
Map.Entry entry = (Map.Entry) obj;
return ((key == null) ? (entry.getKey() == null) : key.equals(entry.getKey())) && ((value == null) ? (entry.getValue() == null) : value.equals(entry.getValue()));
}
public int hashCode() {
return ((key == null) ? 0 : key.hashCode()) ^ ((value == null) ? 0 : value.hashCode());
}
public Object getKey() {
return key;
}
public Object getValue() {
return value;
}
public Object setValue(Object obj) {
context.setAttribute(key, obj);
return value;
}
});
}
// Add servlet context init params
enumeration = context.getInitParameterNames();
while (enumeration.hasMoreElements()) {
final String key = enumeration.nextElement().toString();
final Object value = context.getInitParameter(key);
entries.add(new Map.Entry() {
public boolean equals(Object obj) {
if (!(obj instanceof Map.Entry)) {
return false;
}
Map.Entry entry = (Map.Entry) obj;
return ((key == null) ? (entry.getKey() == null) : key.equals(entry.getKey())) && ((value == null) ? (entry.getValue() == null) : value.equals(entry.getValue()));
}
public int hashCode() {
return ((key == null) ? 0 : key.hashCode()) ^ ((value == null) ? 0 : value.hashCode());
}
public Object getKey() {
return key;
}
public Object getValue() {
return value;
}
public Object setValue(Object obj) {
context.setAttribute(key, obj);
return value;
}
});
}
}
return entries;
}
/**
* Returns the servlet context attribute or init parameter based on the given key. If the
* entry is not found, <tt>null</tt> is returned.
*
* @param key the entry key.
* @return the servlet context attribute or init parameter or <tt>null</tt> if the entry is not found.
*/
public Object get(Object key) {
// Try context attributes first, then init params
// This gives the proper shadowing effects
String keyString = key.toString();
Object value = context.getAttribute(keyString);
return (value == null) ? context.getInitParameter(keyString) : value;
}
/**
* Sets a servlet context attribute given a attribute name and value.
*
* @param key the name of the attribute.
* @param value the value to set.
* @return the attribute that was just set.
*/
public Object put(Object key, Object value) {
Object oldValue = get(key);
entries = null;
context.setAttribute(key.toString(), value);
return oldValue;
}
/**
* Removes the specified servlet context attribute.
*
* @param key the attribute to remove.
* @return the entry that was just removed.
*/
public Object remove(Object key) {
entries = null;
Object value = get(key);
context.removeAttribute(key.toString());
return value;
}
}