/*
 * Copyright 1999-2004 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.commons.jxpath.servlet;

import java.util.Enumeration;
import java.util.HashSet;

import javax.servlet.ServletContext;

import org.apache.commons.jxpath.DynamicPropertyHandler;

/**
 * Implementation of the DynamicPropertyHandler interface that provides
 * access to attributes of a ServletContext.
 *
 * @author Dmitri Plotnikov
 * @version $Revision: 1.6 $ $Date: 2004/05/08 15:10:49 $
 */
public class ServletContextHandler implements DynamicPropertyHandler {
    
    private static final String[] STRING_ARRAY = new String[0];

    public String[] getPropertyNames(Object context) {
        HashSet list = new HashSet(16);
        collectPropertyNames(list, context);
        return (String[]) list.toArray(STRING_ARRAY);
    }
    
    protected void collectPropertyNames(HashSet set, Object bean) {
        Enumeration e = ((ServletContext) bean).getAttributeNames();
        while (e.hasMoreElements()) {
            set.add(e.nextElement());
        }
    }

    public Object getProperty(Object context, String property) {
        return ((ServletContext) context).getAttribute(property);
    }

    public void setProperty(Object context, String property, Object value) {
        ((ServletContext) context).setAttribute(property, value);
    }
}