PortletApplicationMap.java

/*
 * Copyright (c) 2002-2003 by OpenSymphony
 * All rights reserved.
 */
package com.opensymphony.webwork.portlet.dispatcher;

import java.io.Serializable;

import java.util.AbstractMap;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import javax.servlet.ServletContext;
import javax.portlet.PortletContext;


/**
 * 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.
 *
 * @author <a href="mailto:rickard@middleware-company.com">Rickard �berg</a>
 * @author Bill Lynch (docs)
 */
public class PortletApplicationMap extends AbstractMap implements Serializable {
    //~ Instance fields ////////////////////////////////////////////////////////

    PortletContext context;
    Set entries;

    //~ Constructors ///////////////////////////////////////////////////////////

    /**
     * Creates a new map object given the servlet context.
     * @param ctx the servlet context
     */
    public PortletApplicationMap(PortletContext ctx) {
        this.context = ctx;
    }

    //~ Methods ////////////////////////////////////////////////////////////////

    /**
     * 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();

            // 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 Entry() {
                        public boolean equals(Object obj) {
                            Entry entry = (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.toString(), 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 Entry() {
                        public boolean equals(Object obj) {
                            Entry entry = (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.toString(), 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) {
        entries = null;
        context.setAttribute(key.toString(), value);

        return get(key);
    }

    /**
     * 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;
    }
}