rome/src/main/java/com/sun/syndication/feed/WireFeed.java

/*
 * Copyright 2004 Sun Microsystems, Inc.
 * Copyright 2011 ROME Team
 *
 * 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 com.sun.syndication.feed;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import org.jdom2.Element;

import com.sun.syndication.feed.impl.ObjectBean;
import com.sun.syndication.feed.module.Extendable;
import com.sun.syndication.feed.module.Module;
import com.sun.syndication.feed.module.impl.ModuleUtils;

/**
 * Parent class of the RSS (Channel) and Atom (Feed) feed beans.
 * <p>
 * NOTE: We don't like this class at this package level but the alternative
 * would have been a proliferation of packages (one more level to hold atom and
 * rss package with this class just in that package).
 * <p>
 * The format of the 'type' property must be [FEEDNAME]_[FEEDVERSION] with the
 * FEEDNAME in lower case, for example: rss_0.9, rss_0.93, atom_0.3
 * <p>
 * 
 * @author Alejandro Abdelnur
 * 
 */
public abstract class WireFeed implements Cloneable, Serializable, Extendable {
    private static final long serialVersionUID = -3608120400805691829L;
    private final ObjectBean objBean;
    private String feedType;
    private String encoding;
    private List<Module> modules;
    private List<Element> foreignMarkup;

    /**
     * Default constructor, for bean cloning purposes only.
     * <p>
     * 
     */
    protected WireFeed() {
        objBean = new ObjectBean(this.getClass(), this);
    }

    /**
     * Creates a feed for a given type.
     * <p>
     * 
     * @param type of the feed to create.
     * 
     */
    protected WireFeed(final String type) {
        this();
        feedType = type;
    }

    /**
     * Creates a deep 'bean' clone of the object.
     * <p>
     * 
     * @return a clone of the object.
     * @throws CloneNotSupportedException thrown if an element of the object
     *             cannot be cloned.
     * 
     */
    @Override
    public Object clone() throws CloneNotSupportedException {
        return objBean.clone();
    }

    /**
     * Indicates whether some other object is "equal to" this one as defined by
     * the Object equals() method.
     * <p>
     * 
     * @param other he reference object with which to compare.
     * @return <b>true</b> if 'this' object is equal to the 'other' object.
     * 
     */
    @Override
    public boolean equals(final Object other) {
        if (other == null) {
            return false;
        }
        if (!(other instanceof WireFeed)) {
            return false;
        }
        // can't use foreign markup in equals, due to JDOM equals impl
        final List<Element> fm = getForeignMarkup();
        setForeignMarkup(((WireFeed) other).getForeignMarkup());
        final boolean ret = objBean.equals(other);
        // restore foreign markup
        setForeignMarkup(fm);
        return ret;
    }

    /**
     * Returns a hashcode value for the object.
     * <p>
     * It follows the contract defined by the Object hashCode() method.
     * <p>
     * 
     * @return the hashcode of the bean object.
     * 
     */
    @Override
    public int hashCode() {
        return objBean.hashCode();
    }

    /**
     * Returns the String representation for the object.
     * <p>
     * 
     * @return String representation for the object.
     * 
     */
    @Override
    public String toString() {
        return objBean.toString();
    }

    /**
     * Sets the feedType of a the feed. <b>Do not use</b>, for bean cloning
     * purposes only.
     * <p>
     * 
     * @param feedType the feedType of the feed.
     * 
     */
    public void setFeedType(final String feedType) {
        this.feedType = feedType;
    }

    /**
     * Returns the type of the feed.
     * 
     * @return the type of the feed.
     */
    public String getFeedType() {
        return feedType;
    }

    /**
     * Returns the charset encoding of a the feed.
     * <p>
     * This property is not set by feed parsers. But it is used by feed
     * generators to set the encoding in the XML prolog.
     * <p>
     * 
     * @return the charset encoding of the feed.
     * 
     */
    public String getEncoding() {
        return encoding;
    }

    /**
     * Sets the charset encoding of a the feed.
     * <p>
     * This property is not set by feed parsers. But it is used by feed
     * generators to set the encoding in the XML prolog.
     * <p>
     * 
     * @param encoding the charset encoding of the feed.
     * 
     */
    public void setEncoding(final String encoding) {
        this.encoding = encoding;
    }

    /**
     * Returns the channel modules.
     * <p>
     * 
     * @return a list of ModuleImpl elements with the channel modules, an empty
     *         list if none.
     * 
     */
    @Override
    public List<Module> getModules() {
        return modules == null ? (modules = new ArrayList<Module>()) : modules;
    }

    /**
     * Sets the channel modules.
     * <p>
     * 
     * @param modules the list of ModuleImpl elements with the channel modules
     *            to set, an empty list or <b>null</b> if none.
     * 
     */
    @Override
    public void setModules(final List<Module> modules) {
        this.modules = modules;
    }

    /**
     * Returns the module identified by a given URI.
     * <p>
     * 
     * @param uri the URI of the ModuleImpl.
     * @return The module with the given URI, <b>null</b> if none.
     */
    @Override
    public Module getModule(final String uri) {
        return ModuleUtils.getModule(modules, uri);
    }

    /**
     * Returns foreign markup found at channel level.
     * <p>
     * 
     * @return Opaque object to discourage use
     * 
     */
    public List<Element> getForeignMarkup() {
        return foreignMarkup == null ? (foreignMarkup = new ArrayList<Element>()) : foreignMarkup;
    }

    /**
     * Sets foreign markup found at channel level.
     * <p>
     * 
     * @param foreignMarkup Opaque object to discourage use
     * 
     */
    public void setForeignMarkup(final List<Element> foreignMarkup) {
        this.foreignMarkup = foreignMarkup;
    }
}