org.exist.xquery.modules.xslfo.ApacheFopProcessorAdapter Maven / Gradle / Ivy
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eXist-db XQuery XSL:FO Module
package org.exist.xquery.modules.xslfo;
import java.io.OutputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashSet;
import java.util.Map.Entry;
import java.util.Properties;
import java.util.Set;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.SAXConfigurationHandler;
import org.apache.fop.apps.*;
import org.apache.fop.apps.io.ResourceResolverFactory;
import org.apache.fop.events.Event;
import org.apache.fop.events.EventFormatter;
import org.apache.fop.events.EventListener;
import org.apache.fop.events.model.EventSeverity;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LogManager;
import org.apache.xmlgraphics.io.ResourceResolver;
import org.apache.xmlgraphics.io.URIResolverAdapter;
import org.exist.storage.DBBroker;
import org.exist.xslt.EXistURIResolver;
import org.exist.xquery.value.NodeValue;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.URIResolver;
/**
* @author Adam Retter
*/
public class ApacheFopProcessorAdapter implements ProcessorAdapter {
private static final Logger LOG = LogManager.getLogger(ApacheFopProcessorAdapter.class);
private static final String DEFAULT_BASE_URI = "exist://localhost/db/";
@Override
public ContentHandler getContentHandler(final DBBroker broker, final NodeValue configFile, final Properties parameters, final String mimeType, final OutputStream os) throws SAXException {
// setup the FopFactory
final FopFactoryBuilder builder;
try {
if (configFile != null) {
final FopConfigurationBuilder cfgBuilder = new FopConfigurationBuilder(broker);
final Configuration cfg = cfgBuilder.buildFromNode(configFile);
final URI defaultBaseURI;
if(configFile instanceof org.exist.dom.memtree.NodeImpl) {
//in-memory documents don't have a BaseURI
defaultBaseURI = new URI(DEFAULT_BASE_URI);
} else {
defaultBaseURI = new URI("exist://localhost" + configFile.getOwnerDocument().getBaseURI());
}
final EnvironmentProfile environment = EnvironmentalProfileFactory.createDefault(defaultBaseURI, getResourceResolver(broker, defaultBaseURI.toString()));
builder = new FopFactoryBuilder(environment).setConfiguration(cfg);
} else {
final URI defaultBaseURI = new URI(DEFAULT_BASE_URI);
final EnvironmentProfile environment = EnvironmentalProfileFactory.createDefault(defaultBaseURI, getResourceResolver(broker, defaultBaseURI.toString()));
builder = new FopFactoryBuilder(environment);
}
final FopFactory fopFactory = builder.build();
// setup the foUserAgent, using given parameters held in the
// transformer handler
final FOUserAgent foUserAgent = setupFOUserAgent(fopFactory.newFOUserAgent(), parameters);
foUserAgent.getEventBroadcaster().addEventListener(new ExistLoggingEventListener(LOG));
// create new instance of FOP using the mimetype, the created user
// agent, and the output stream
final Fop fop = fopFactory.newFop(mimeType, foUserAgent, os);
// Obtain FOP's DefaultHandler
return fop.getDefaultHandler();
} catch(final URISyntaxException e) {
throw new SAXException("Unable to parse baseURI", e);
}
}
@Override
public void cleanup() {
}
/**
* Setup the UserAgent for FOP, from given parameters *
*
* @param foUserAgent The user agent to set parameters for
* @param parameters
* any user defined parameters to the XSL-FO process
* @return FOUserAgent The generated FOUserAgent to include any parameters
* passed in
*/
private FOUserAgent setupFOUserAgent(final FOUserAgent foUserAgent, final Properties parameters) {
// setup the foUserAgent as per the parameters given
foUserAgent.setProducer("eXist-db with Apache FOP");
if(parameters != null) {
for(final Entry paramEntry : parameters.entrySet()) {
final String key = (String)paramEntry.getKey();
final String value = (String)paramEntry.getValue();
if(key.equals("FOPauthor")) {
foUserAgent.setAuthor(value);
} else if(key.equals("FOPtitle")) {
foUserAgent.setTitle(value);
} else if(key.equals("FOPkeywords")) {
foUserAgent.setTitle(value);
} else if(key.equals("FOPdpi")) {
try {
foUserAgent.setTargetResolution(Integer.parseInt(value));
} catch(final NumberFormatException nfe) {
LOG.warn("Unable to set DPI to: " + value);
}
}
}
}
return foUserAgent;
}
/**
* Returns a scheme aware ResourceResolver which supports:
* file://
* exist:// (which will be translated to xmldb:exist://)
* http://
* https://
*
* @return The resource resolver
*/
private ResourceResolver getResourceResolver(final DBBroker broker, final String baseUri) {
final ResourceResolverFactory.SchemeAwareResourceResolverBuilder builder = ResourceResolverFactory.createSchemeAwareResourceResolverBuilder(ResourceResolverFactory.createDefaultResourceResolver());
final URIResolverAdapter uriResolver = new URIResolverAdapter(
new ExistSchemeRewriter(new EXistURIResolver(broker.getBrokerPool(), baseUri))
);
builder.registerResourceResolverForScheme("exist", uriResolver);
builder.registerResourceResolverForScheme("http", uriResolver);
builder.registerResourceResolverForScheme("https", uriResolver);
return builder.build();
}
/**
* Rewrites URLs like:
* exist://localhost/db -> /db
*/
private static class ExistSchemeRewriter implements URIResolver {
private final EXistURIResolver eXistURIResolver;
public ExistSchemeRewriter(final EXistURIResolver eXistURIResolver) {
this.eXistURIResolver = eXistURIResolver;
}
@Override
public Source resolve(final String href, final String base) throws TransformerException {
return eXistURIResolver.resolve(
rewriteScheme(href),
rewriteScheme(base)
);
}
private String rewriteScheme(String uri) {
if(uri != null) {
if (uri.startsWith("exist://localhost")) {
uri = uri.replace("exist://localhost/db", "/db");
} else if (uri.startsWith("exist://")) {
uri = uri.replace("exist://", "xmldb:exist://");
}
}
return uri;
}
}
/**
* Extension of the Apache Avalon DefaultConfigurationBuilder Allows better
* integration with Nodes passed in from eXist as Configuration files
*/
private static class FopConfigurationBuilder extends org.apache.avalon.framework.configuration.DefaultConfigurationBuilder {
private final DBBroker broker;
public FopConfigurationBuilder(final DBBroker broker) {
super();
this.broker = broker;
}
@SuppressWarnings("unused")
public FopConfigurationBuilder(final DBBroker broker, final boolean enableNamespaces) {
super(enableNamespaces);
this.broker = broker;
}
public Configuration buildFromNode(final NodeValue configFile) throws SAXException {
final SAXConfigurationHandler handler = getHandler();
handler.clear();
configFile.toSAX(broker, handler, new Properties());
return handler.getConfiguration();
}
}
private static class ExistLoggingEventListener implements EventListener {
private final Logger log;
private final Set loggedMessages = new HashSet<>();
public ExistLoggingEventListener(final Logger log) {
this.log = log;
}
@Override
public void processEvent(final Event event) {
String msg = EventFormatter.format(event);
EventSeverity severity = event.getSeverity();
if (severity == EventSeverity.INFO) {
log.info(msg);
} else if (severity == EventSeverity.WARN) {
// we want to prevent logging of duplicate messages in situations where they are likely
// to occur; for instance, warning related to layout do not repeat (since line number
// will be different) and as such we do not try to filter them here; on the other hand,
// font related warnings are very likely to repeat and we try to filter them out here;
// the same may happen with missing images (but not implemented yet).
String eventGroupID = event.getEventGroupID();
if (eventGroupID.equals("org.apache.fop.fonts.FontEventProducer")) {
if (!loggedMessages.contains(msg)) {
loggedMessages.add(msg);
log.warn(msg);
}
} else {
log.warn(msg);
}
} else if (severity == EventSeverity.ERROR) {
if (event.getParam("e") != null) {
log.error(msg, (Throwable)event.getParam("e"));
} else {
log.error(msg);
}
} else if (severity == EventSeverity.FATAL) {
if (event.getParam("e") != null) {
log.fatal(msg, (Throwable)event.getParam("e"));
} else {
log.fatal(msg);
}
} else {
assert false;
}
}
}
}
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