bundle.java

DSPACE的源码 dspace-1.4-source

/*
 * Bundle.java
 *
 * Version: $Revision: 1.25 $
 *
 * Date: $Date: 2006/05/26 14:16:20 $
 *
 * Copyright (c) 2002-2005, Hewlett-Packard Company and Massachusetts
 * Institute of Technology.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Hewlett-Packard Company nor the name of the
 * Massachusetts Institute of Technology nor the names of their
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */
package org.dspace.content;

import java.io.IOException;
import java.io.InputStream;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;

import org.apache.log4j.Logger;
import org.dspace.authorize.AuthorizeException;
import org.dspace.authorize.AuthorizeManager;
import org.dspace.core.Constants;
import org.dspace.core.Context;
import org.dspace.core.LogManager;
import org.dspace.storage.rdbms.DatabaseManager;
import org.dspace.storage.rdbms.TableRow;
import org.dspace.storage.rdbms.TableRowIterator;

/**
 * Class representing bundles of bitstreams stored in the DSpace system
 * <P>
 * The corresponding Bitstream objects are loaded into memory. At present, there
 * is no metadata associated with bundles - they are simple containers. Thus,
 * the <code>update</code> method doesn't do much yet. Creating, adding or
 * removing bitstreams has instant effect in the database.
 * 
 * @author Robert Tansley
 * @version $Revision: 1.25 $
 */
public class Bundle extends DSpaceObject
{
    /** log4j logger */
    private static Logger log = Logger.getLogger(Bundle.class);

    /** Our context */
    private Context ourContext;

    /** The table row corresponding to this bundle */
    private TableRow bundleRow;

    /** The bitstreams in this bundle */
    private List bitstreams;

    /**
     * Construct a bundle object with the given table row
     * 
     * @param context
     *            the context this object exists in
     * @param row
     *            the corresponding row in the table
     */
    Bundle(Context context, TableRow row) throws SQLException
    {
        ourContext = context;
        bundleRow = row;
        bitstreams = new ArrayList();

        // Get bitstreams
        TableRowIterator tri = DatabaseManager.queryTable(
                ourContext, "bitstream",
                "SELECT bitstream.* FROM bitstream, bundle2bitstream WHERE "
                        + "bundle2bitstream.bitstream_id=bitstream.bitstream_id AND "
                        + "bundle2bitstream.bundle_id= ? ",
                bundleRow.getIntColumn("bundle_id"));
        
        while (tri.hasNext())
        {
            TableRow r = (TableRow) tri.next();

            // First check the cache
            Bitstream fromCache = (Bitstream) context.fromCache(
                    Bitstream.class, r.getIntColumn("bitstream_id"));

            if (fromCache != null)
            {
                bitstreams.add(fromCache);
            }
            else
            {
                bitstreams.add(new Bitstream(ourContext, r));
            }
        }
        // close the TableRowIterator to free up resources
        tri.close();

        // Cache ourselves
        context.cache(this, row.getIntColumn("bundle_id"));
    }

    /**
     * Get a bundle from the database. The bundle and bitstream metadata are all
     * loaded into memory.
     * 
     * @param context
     *            DSpace context object
     * @param id
     *            ID of the bundle
     * 
     * @return the bundle, or null if the ID is invalid.
     */
    public static Bundle find(Context context, int id) throws SQLException
    {
        // First check the cache
        Bundle fromCache = (Bundle) context.fromCache(Bundle.class, id);

        if (fromCache != null)
        {
            return fromCache;
        }

        TableRow row = DatabaseManager.find(context, "bundle", id);

        if (row == null)
        {
            if (log.isDebugEnabled())
            {
                log.debug(LogManager.getHeader(context, "find_bundle",
                        "not_found,bundle_id=" + id));
            }

            return null;
        }
        else
        {
            if (log.isDebugEnabled())
            {
                log.debug(LogManager.getHeader(context, "find_bundle",
                        "bundle_id=" + id));
            }

            return new Bundle(context, row);
        }
    }

    /**
     * Create a new bundle, with a new ID. This method is not public, since
     * bundles need to be created within the context of an item. For this
     * reason, authorisation is also not checked; that is the responsibility of
     * the caller.
     * 
     * @param context
     *            DSpace context object
     * 
     * @return the newly created bundle
     */
    static Bundle create(Context context) throws SQLException
    {
        // Create a table row
        TableRow row = DatabaseManager.create(context, "bundle");

        log.info(LogManager.getHeader(context, "create_bundle", "bundle_id="
                + row.getIntColumn("bundle_id")));

        return new Bundle(context, row);
    }

    /**
     * Get the internal identifier of this bundle
     * 
     * @return the internal identifier
     */
    public int getID()
    {
        return bundleRow.getIntColumn("bundle_id");
    }

    /**
     * Get the name of the bundle
     * 
     * @return name of the bundle (ORIGINAL, TEXT, THUMBNAIL) or NULL if not set
     */
    public String getName()
    {
        return bundleRow.getStringColumn("name");
    }

    /**
     * Set the name of the bundle
     * 
     * @param name
     *            string name of the bundle (ORIGINAL, TEXT, THUMBNAIL) are the
     *            values currently used
     */
    public void setName(String name)
    {
        bundleRow.setColumn("name", name);
    }

    /**
     * Get the primary bitstream ID of the bundle
     * 
     * @return primary bitstream ID or -1 if not set
     */
    public int getPrimaryBitstreamID()
    {
        return bundleRow.getIntColumn("primary_bitstream_id");
    }

    /**
     * Set the primary bitstream ID of the bundle
     * 
     * @param bitstreamID
     *            int ID of primary bitstream (e.g. index html file)
     */
    public void setPrimaryBitstreamID(int bitstreamID)
    {
        bundleRow.setColumn("primary_bitstream_id", bitstreamID);
    }

    public String getHandle()
    {
        // No Handles for bundles
        return null;
    }

    /**
     * @param name
     *            name of the bitstream you're looking for
     * 
     * @return the bitstream or null if not found
     */
    public Bitstream getBitstreamByName(String name)
    {