DownloadCPServlet.java

/**********************************************************************************
 * $URL: 
 * $Id: 
 ***********************************************************************************
 *
 * Copyright (c) 2007, 2008, 2009 The Sakai Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.tool.assessment.ui.servlet.cp;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
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 org.sakaiproject.authz.cover.SecurityService;
import org.sakaiproject.tool.assessment.contentpackaging.ManifestGenerator;
import org.sakaiproject.tool.assessment.facade.AgentFacade;
import org.sakaiproject.tool.assessment.services.assessment.AssessmentService;
import org.sakaiproject.tool.assessment.ui.bean.qti.XMLController;
import org.sakaiproject.tool.assessment.ui.bean.shared.PersonBean;
import org.sakaiproject.tool.assessment.ui.listener.util.ContextUtil;


/**
 * <p>Title: Samigo</p>
 * @version $Id: DownloadCPServlet.java 106463 2012-04-02 12:20:09Z david.horwitz@uct.ac.za $
 */

public class DownloadCPServlet extends HttpServlet {

	private static Log log = LogFactory.getLog(DownloadCPServlet.class);

	/**
	 * passthu to post
	 * 
	 * @param req
	 * @param res
	 * @throws ServletException
	 * @throws IOException
	 */
	public void doGet(HttpServletRequest req, HttpServletResponse res)
			throws ServletException, IOException {
		doPost(req, res);
	}

	/**
	 * Get the faces context and display the contents of the XMLDisplay bean
	 * 
	 * @param req
	 * @param res
	 * @throws ServletException
	 * @throws IOException
	 */
	public void doPost(HttpServletRequest req, HttpServletResponse res)
	throws ServletException, IOException {
		String assessmentId = req.getParameter("assessmentId");

		//update random question pools (if any) before exporting
		AssessmentService assessmentService = new AssessmentService();
		int success = assessmentService.updateAllRandomPoolQuestions(assessmentService.getAssessment(assessmentId));
		if(success == AssessmentService.UPDATE_SUCCESS){
			String agentIdString = getAgentString(req, res);
			String currentSiteId = assessmentService
			.getAssessmentSiteId(assessmentId);
			String assessmentCreatedBy = assessmentService
			.getAssessmentCreatedBy(assessmentId);
			boolean accessDenied = true;
			if (canExport(req, res, agentIdString, currentSiteId,
					assessmentCreatedBy)) {
				accessDenied = false;
			}

			if (accessDenied) {
				String path = "/jsf/qti/exportDenied.faces";
				RequestDispatcher dispatcher = req.getRequestDispatcher(path);
				dispatcher.forward(req, res);
			} else {
				res.setContentType("application/x-zip-compressed");
				String zipFilename = "exportAssessment.zip";
				res.setHeader("Content-Disposition", "attachment;filename=\""
						+ zipFilename + "\";");

				ServletOutputStream outputStream = null;
				//BufferedInputStream bufInputStream = null;
				ZipOutputStream zos = null;
				ZipEntry ze = null;

				try {
					byte[] b = null;
					outputStream = res.getOutputStream();
					zos = new ZipOutputStream(outputStream);

					// QTI file
					ze = new ZipEntry("exportAssessment.xml");
					zos.putNextEntry(ze);
					XMLController xmlController = (XMLController) ContextUtil
					.lookupBeanFromExternalServlet("xmlController", req,
							res);
					xmlController.setId(assessmentId);
					xmlController.setQtiVersion(1);
					xmlController.displayAssessmentXml();
					String qtiString = xmlController.getXmlBean().getXml();
					log.debug("qtiString = " + qtiString);
					b = qtiString.getBytes();
					zos.write(b, 0, b.length);
					zos.closeEntry();

					// imsmanifest.xml
					ze = new ZipEntry("imsmanifest.xml");
					zos.putNextEntry(ze);
					ManifestGenerator manifestGenerator = new ManifestGenerator(
							assessmentId);
					String manString = manifestGenerator.getManifest();
					log.debug("manString = " + manString);
					b = manString.getBytes();
					zos.write(b, 0, b.length);
					zos.closeEntry();

					// Attachments
					HashMap contentMap = manifestGenerator.getContentMap();

					String filename = null;
					for (Iterator it = contentMap.entrySet().iterator(); it.hasNext();) {
						Map.Entry entry = (Map.Entry) it.next();
						filename = (String)  entry.getKey();
						ze = new ZipEntry(filename.substring(1));
						zos.putNextEntry(ze);
						b = (byte[]) entry.getValue();
						zos.write(b, 0, b.length);
						zos.closeEntry();
					}

				} catch (IOException e) {
					log.error(e.getMessage());
					throw e;
				} finally {
					if (zos != null) {
						try {
							zos.closeEntry();
						} catch (IOException e) {
							log.error(e.getMessage());
						}
						try {
							zos.close();
						} catch (IOException e) {
							log.error(e.getMessage());
						}

					}
				}
			}
		}else{
			if(success == AssessmentService.UPDATE_ERROR_DRAW_SIZE_TOO_LARGE){  		    		
				String err=ContextUtil.getLocalizedString("org.sakaiproject.tool.assessment.bundle.AuthorMessages","update_pool_error_size_too_large");
				req.setAttribute("error", err);
			}else{
				String err=ContextUtil.getLocalizedString("org.sakaiproject.tool.assessment.bundle.AuthorMessages","update_pool_error_unknown");
				req.setAttribute("error", err);
			}

			String path = "/jsf/qti/poolUpdateError.faces";
			RequestDispatcher dispatcher = req.getRequestDispatcher(path);
			dispatcher.forward(req, res);
		}
	}

	private boolean isOwner(String agentId, String ownerId) {
		boolean isOwner = false;
		isOwner = agentId.equals(ownerId);
		return isOwner;
	}

	private String getAgentString(HttpServletRequest req,
			HttpServletResponse res) {
		String agentIdString = AgentFacade.getAgentString();
		if (agentIdString == null || agentIdString.equals("")) { // try this
			PersonBean person = (PersonBean) ContextUtil
					.lookupBeanFromExternalServlet("person", req, res);
			agentIdString = person.getAnonymousId();
		}
		return agentIdString;
	}

	public boolean canExport(HttpServletRequest req, HttpServletResponse res,
			String agentId, String currentSiteId, String createdBy) {
		log.debug("agentId=" + agentId);
		log.debug("currentSiteId=" + currentSiteId);
		boolean hasPrivilege_any = hasPrivilege(req, "edit_any_assessment",
				currentSiteId);
		boolean hasPrivilege_own = hasPrivilege(req, "edit_own_assessment",
				currentSiteId);
		log.debug("hasPrivilege_any=" + hasPrivilege_any);
		log.debug("hasPrivilege_own=" + hasPrivilege_own);
		boolean hasPrivilege = (hasPrivilege_any || (hasPrivilege_own && isOwner(
				agentId, createdBy)));
		return hasPrivilege;

	}

	public boolean hasPrivilege(HttpServletRequest req, String functionKey,
			String context) {
		String functionName = (String) ContextUtil.getLocalizedString(req,
				"org.sakaiproject.tool.assessment.bundle.AuthzPermissions",
				functionKey);
		boolean privilege = SecurityService.unlock(functionName, "/site/"
				+ context);
		return privilege;
	}
}