org.opencms.pdftools.CmsPdfUserAgent Maven / Gradle / Ivy
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/*
* This library is part of OpenCms -
* the Open Source Content Management System
*
* Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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.
*
* For further information about Alkacon Software, please see the
* company website: http://www.alkacon.com
*
* For further information about OpenCms, please see the
* project website: http://www.opencms.org
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.opencms.pdftools;
import org.opencms.file.CmsFile;
import org.opencms.file.CmsObject;
import org.opencms.loader.CmsImageScaler;
import org.opencms.main.CmsException;
import org.opencms.main.CmsLog;
import org.opencms.main.OpenCms;
import java.io.ByteArrayInputStream;
import java.net.URI;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.logging.Log;
import org.xhtmlrenderer.extend.FSImage;
import org.xhtmlrenderer.layout.SharedContext;
import org.xhtmlrenderer.pdf.ITextFSImage;
import org.xhtmlrenderer.resource.CSSResource;
import org.xhtmlrenderer.resource.ImageResource;
import org.xhtmlrenderer.swing.NaiveUserAgent;
import com.lowagie.text.Image;
/**
* This class is responsible for loading external resources while generating PDF from XHTML.
*
* Resources will be loaded from the VFS. Additionally, if there are image scaler parameters in an image
* URI, the scaled image data will be returned. Please note that this class just reads the data from the linked
* resources; it will not go through OpenCms's resource loaders, so you can't e.g. use a JSP as a dynamic stylesheet.
*/
public class CmsPdfUserAgent extends NaiveUserAgent {
/** The regex to match image scaler parameters. */
public static final Pattern SCALE_PARAMS_PATTERN = Pattern.compile("__scale=(.*?)(?:&|$)");
/** The image cache capacity. */
private static final int IMAGE_CACHE_CAPACITY = 64;
/** The logger instance for this class. */
private static final Log LOG = CmsLog.getLog(CmsPdfUserAgent.class);
/** The CMS context to use for loading the resources. */
private CmsObject m_cms;
/** The CMS context to use, with the site root set to the root site. */
private CmsObject m_rootCms;
/** The shared context. */
private SharedContext m_sharedContext;
/**
* Creates a new instance.
*
* @param cms the CMS context
*
* @throws CmsException if something goes wrong
*/
public CmsPdfUserAgent(CmsObject cms)
throws CmsException {
super(IMAGE_CACHE_CAPACITY);
m_cms = cms;
m_rootCms = OpenCms.initCmsObject(cms);
m_rootCms.getRequestContext().setSiteRoot("");
}
/**
* @see org.xhtmlrenderer.swing.NaiveUserAgent#getBinaryResource(java.lang.String)
*/
@Override
public byte[] getBinaryResource(String uri) {
return readFile(uri);
}
/**
* @see org.xhtmlrenderer.swing.NaiveUserAgent#getCSSResource(java.lang.String)
*/
@Override
public CSSResource getCSSResource(String uri) {
return new CSSResource(getStream(readFile(uri)));
}
/**
* @see org.xhtmlrenderer.swing.NaiveUserAgent#getImageResource(java.lang.String)
*/
@SuppressWarnings("unchecked")
@Override
public ImageResource getImageResource(String uri) {
ImageResource resource = null;
resource = (ImageResource)_imageCache.get(uri);
if (resource == null) {
byte[] imageData = readImage(uri);
if (imageData != null) {
try {
Image image = Image.getInstance(imageData);
scaleToOutputResolution(image);
resource = new ImageResource(uri, new ITextFSImage(image));
_imageCache.put(uri, resource);
} catch (Exception e) {
LOG.error("Problem with getting image resource " + uri, e);
}
}
}
if (resource != null) {
resource = new ImageResource(resource.getImageUri(), (FSImage)((ITextFSImage)resource.getImage()).clone());
} else {
resource = new ImageResource(uri, null);
}
return resource;
}
/**
* Gets the shared context.
*
* @return the shared context
*/
public SharedContext getSharedContext() {
return m_sharedContext;
}
/**
* @see org.xhtmlrenderer.swing.NaiveUserAgent#resolveURI(java.lang.String)
*/
@Override
public String resolveURI(String uri) {
// we want to pass the uri unchanged to the get... methods
return uri;
}
/**
* Sets the shared context.
*
* @param sharedContext the shared context
*/
public void setSharedContext(SharedContext sharedContext) {
m_sharedContext = sharedContext;
}
/**
* Converts a byte array to an input stream, but returns null if the byte array is null.
*
* @param data the data
* @return the input stream for the data, or null
*/
ByteArrayInputStream getStream(byte[] data) {
if (data == null) {
return null;
} else {
return new ByteArrayInputStream(data);
}
}
/**
* Reads a file from the VFS.
*
* @param uriWithParams the
* @return the file data
*/
private byte[] readFile(String uriWithParams) {
try {
String pathAndQuery = OpenCms.getLinkManager().getRootPath(m_cms, uriWithParams);
URI uri = new URI(pathAndQuery);
String path = uri.getPath();
CmsFile file = m_rootCms.readFile(path);
return file.getContents();
} catch (Exception e) {
LOG.error("Problem with reading CSS " + uriWithParams + ": " + e.getLocalizedMessage(), e);
return null;
}
}
/**
* Reads an image from the VFS, scaling it if necessary.
*
* @param uriWithParams the image uri, possible with scaling parameter
*
* @return the image data
*/
private byte[] readImage(String uriWithParams) {
try {
String pathAndQuery = OpenCms.getLinkManager().getRootPath(m_cms, uriWithParams);
URI uri = new URI(pathAndQuery);
String path = uri.getPath();
String query = uri.getQuery();
String scaleParams = null;
if (query != null) {
Matcher matcher = SCALE_PARAMS_PATTERN.matcher(query);
if (matcher.find()) {
scaleParams = matcher.group(1);
}
}
CmsFile imageFile = m_rootCms.readFile(path);
byte[] result = imageFile.getContents();
if (scaleParams != null) {
CmsImageScaler scaler = new CmsImageScaler(scaleParams);
result = scaler.scaleImage(imageFile);
}
return result;
} catch (Exception e) {
LOG.error("Problem with reading image " + uriWithParams + ": " + e.getLocalizedMessage(), e);
return null;
}
}
/**
* Scales the image to output resolution.
*
* @param image the image to scale
*/
private void scaleToOutputResolution(Image image) {
float factor = m_sharedContext.getDotsPerPixel();
if (factor != 1.0f) {
image.scaleAbsolute(image.getPlainWidth() * factor, image.getPlainHeight() * factor);
}
}
}