eu.planets_project.tb.impl.data.util.TBDigitalObjectContentResolver.java Source code

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Here is the source code for eu.planets_project.tb.impl.data.util.TBDigitalObjectContentResolver.java

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/*******************************************************************************
 * Copyright (c) 2007, 2010 The Planets Project Partners.
 *
 * All rights reserved. This program and the accompanying 
 * materials are made available under the terms of the 
 * Apache License, Version 2.0 which accompanies 
 * this distribution, and is available at 
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 *******************************************************************************/
package eu.planets_project.tb.impl.data.util;

import java.io.IOException;
import java.io.InputStream;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import eu.planets_project.ifr.core.storage.api.DigitalObjectManager.DigitalObjectNotFoundException;
import eu.planets_project.ifr.core.storage.impl.util.PDURI;
import eu.planets_project.services.datatypes.DigitalObject;
import eu.planets_project.services.datatypes.Metadata;
import eu.planets_project.tb.api.data.util.DigitalObjectRefBean;

/**
 * This servlet returns the content stored in the JCR repo for the provided
 * digital object id (permanent uri).
 * 
 * @author <a href="mailto:christian.sadilek@ait.ac.at">Christian Sadilek</a>
 */
public class TBDigitalObjectContentResolver extends HttpServlet {
    private static final long serialVersionUID = -8269793550349486731L;

    private static Log log = LogFactory.getLog(TBDigitalObjectContentResolver.class);
    private DataHandlerImpl dh = new DataHandlerImpl();

    private static final int BUFFER_SIZE = 4096;
    private static final String ID_PARAMETER_NAME = "id";
    private static final String MIME_TYPE_METADATA_NAME = "mimeType";

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        InputStream is = null;
        String id = request.getParameter(ID_PARAMETER_NAME);

        try {
            if (id == null)
                throw new DigitalObjectNotFoundException("id is null");

            // Fix up any encoding issues:
            id = PDURI.encodePlanetsUriStringAsUri(id).toASCIIString();

            DigitalObjectRefBean digoRef = dh.get(id);
            if (digoRef == null)
                throw new DigitalObjectNotFoundException("digital object " + id + " not found");

            // set the metadata if it's contained within the digital object
            DigitalObject object = digoRef.getDigitalObject();
            for (Metadata md : object.getMetadata()) {
                if (md.getName().equals(MIME_TYPE_METADATA_NAME))
                    response.setContentType(md.getContent());
            }

            is = digoRef.getContentAsStream();

            // read from input stream and write to client
            int bytesRead = 0;
            byte[] buffer = new byte[BUFFER_SIZE];
            while ((bytesRead = is.read(buffer)) != -1) {
                response.getOutputStream().write(buffer, 0, bytesRead);
            }
        } catch (DigitalObjectNotFoundException e) {
            log.info(e.getMessage(), e);
            response.sendError(HttpServletResponse.SC_NOT_FOUND, "object not found with id=" + id);
        } finally {
            if (is != null)
                is.close();
        }
    }
}