be.fedict.eid.dss.webapp.DocumentViewerServlet.java Source code

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Here is the source code for be.fedict.eid.dss.webapp.DocumentViewerServlet.java

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/*
 * eID Digital Signature Service Project.
 * Copyright (C) 2009 FedICT.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version
 * 3.0 as published by the Free Software Foundation.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, see 
 * http://www.gnu.org/licenses/.
 */

package be.fedict.eid.dss.webapp;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

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

import be.fedict.eid.dss.control.View;
import be.fedict.eid.dss.model.DocumentRepository;
import be.fedict.eid.dss.spi.DSSDocumentService;
import be.fedict.eid.dss.spi.DocumentVisualization;
import be.fedict.eid.dss.spi.MimeType;

/**
 * A servlet for visualizing a document.
 * 
 * @author Frank Cornelis.
 */
public class DocumentViewerServlet extends AbstractProtocolServiceServlet {

    private static final long serialVersionUID = 1L;

    private static final Log LOG = LogFactory.getLog(DocumentViewerServlet.class);

    private static final String RESOURCE_PARAM = "resource";

    public DocumentViewerServlet() {
        super(false, true);
    }

    private void handleDownloadRequest(String resourceId, HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {

        LOG.debug("handle download: " + resourceId);

        HttpSession httpSession = request.getSession();
        DocumentRepository documentRepository = new DocumentRepository(httpSession);
        String contentType = documentRepository.getDocumentContentType();
        if (null == contentType) {
            response.setContentType("text/plain");
            PrintWriter printWriter = response.getWriter();
            printWriter.println("No document to be signed.");
            return;
        }

        byte[] documentData = documentRepository.getDocument();

        DSSDocumentService documentService = super.findDocumentService(contentType);
        if (null != documentService) {
            DocumentVisualization documentVisualization;
            try {
                documentVisualization = documentService.findDocument(documentData, resourceId);
            } catch (Exception e) {
                throw new ServletException("error finding the document: " + e.getMessage(), e);
            }
            if (null != documentVisualization) {
                contentType = documentVisualization.getBrowserContentType();
                documentData = documentVisualization.getBrowserData();
            }
        }

        setResponseHeaders(request, response);

        response.setContentType(contentType);
        response.setContentLength(documentData.length);
        ServletOutputStream out = response.getOutputStream();
        out.write(documentData);
        out.flush();
    }

    @Override
    protected void handleRequest(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {

        LOG.debug("doGet");

        String resource = request.getParameter(RESOURCE_PARAM);
        if (null != resource) {

            // download/view request
            handleDownloadRequest(resource, request, response);
            return;
        }

        // get browser plugins
        List<String> plugins = BrowserInfoServlet.getPlugins(request.getSession());
        for (String plugin : plugins) {
            LOG.debug("Plugin: " + plugin);
        }

        // get browser mimeTypes
        List<MimeType> mimeTypes = BrowserInfoServlet.getMimeTypes(request.getSession());
        for (MimeType mimeType : mimeTypes) {
            LOG.debug("MimeTypes: type=" + mimeType.getType() + " plugin=" + mimeType.getPlugin());
        }

        HttpSession httpSession = request.getSession();
        DocumentRepository documentRepository = new DocumentRepository(httpSession);
        String contentType = documentRepository.getDocumentContentType();
        if (null == contentType) {
            response.setContentType("text/plain");
            PrintWriter printWriter = response.getWriter();
            printWriter.println("No document to be signed.");
            return;
        }

        byte[] documentData = documentRepository.getDocument();

        DSSDocumentService documentService = super.findDocumentService(contentType);
        if (null != documentService) {
            LOG.debug("document visualization transformation");
            String language = (String) httpSession.getAttribute(View.LANGUAGE_SESSION_ATTRIBUTE);
            DocumentVisualization documentVisualization;
            try {
                documentVisualization = documentService.visualizeDocument(documentData, language, mimeTypes,
                        "./document?" + RESOURCE_PARAM + "=");
            } catch (Exception e) {
                throw new ServletException("error visualizing the document: " + e.getMessage(), e);
            }
            if (null != documentVisualization) {
                contentType = documentVisualization.getBrowserContentType();
                documentData = documentVisualization.getBrowserData();
            }
        }

        setResponseHeaders(request, response);

        response.setContentType(contentType);
        response.setContentLength(documentData.length);
        ServletOutputStream out = response.getOutputStream();
        out.write(documentData);
        out.flush();
    }

    private void setResponseHeaders(HttpServletRequest request, HttpServletResponse response) {

        response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate, max-age=-1"); // http
        // 1.1
        if (!request.getScheme().equals("https")) {
            // else the download fails in IE
            response.setHeader("Pragma", "no-cache"); // http 1.0
        } else {
            response.setHeader("Pragma", "public");
        }
        response.setDateHeader("Expires", -1);

    }
}