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- /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache 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.apache.org/licenses/LICENSE-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.
- */
-
- /* $Id$ */
-
- package org.apache.fop.fo;
-
- import java.io.InputStream;
-
- import javax.xml.transform.Result;
- import javax.xml.transform.Source;
- import javax.xml.transform.Transformer;
- import javax.xml.transform.TransformerConfigurationException;
- import javax.xml.transform.TransformerException;
- import javax.xml.transform.TransformerFactory;
- import javax.xml.transform.sax.SAXResult;
- import javax.xml.transform.stream.StreamSource;
-
- import org.apache.fop.apps.FOPException;
- import org.apache.fop.apps.FOUserAgent;
- import org.apache.fop.apps.Fop;
- import org.apache.fop.apps.FopFactory;
- import org.apache.fop.events.EventListener;
-
- /**
- * Parse an FO document and run the corresponding FO events through a given
- * {@link FOEventHandler} instance. That instance is created using the helper
- * {@link FOEventHandlerFactory}.
- *
- * <p>An instance of this class may not be used in multiple threads concurrently.<p>
- *
- * <p>An instance of this class may be used multiple times if the given
- * {@link FOEventHandler} implementation can be used multiple times.
- */
- public final class FODocumentParser {
-
- private static final TransformerFactory TRANSFORMER_FACTORY = TransformerFactory.newInstance();
-
- private static final FopFactory FOP_FACTORY = FopFactory.newInstance();
-
- private final FOEventHandlerFactory foEventHandlerFactory;
-
- private Fop fop;
-
- private Transformer transformer;
-
- private EventListener eventListener;
-
- /**
- * A factory to create custom instances of {@link FOEventHandler}.
- */
- public static interface FOEventHandlerFactory {
-
- /**
- * Creates a new {@code FOEventHandler} instance parameterized with the given FO user agent.
- *
- * @param foUserAgent an FO user agent
- * @return a new {@code FOEventHandler} instance
- */
- FOEventHandler newFOEventHandler(FOUserAgent foUserAgent);
- }
-
- private FODocumentParser(FOEventHandlerFactory foeEventHandlerFactory) {
- this.foEventHandlerFactory = foeEventHandlerFactory;
- }
-
- /**
- * Creates and returns a new FO document parser. The given factory will be used to
- * customize the handler that will receive FO events, using the
- * {@link FOUserAgent#setFOEventHandlerOverride(FOEventHandler)} method.
- *
- * @param foEventHandlerFactory the factory to be used to create {@code
- * FOEventHandler} instances
- * @return a new parser
- */
- public static FODocumentParser newInstance(FOEventHandlerFactory foEventHandlerFactory) {
- return new FODocumentParser(foEventHandlerFactory);
- }
-
- /**
- * Sets the event listener to be used if events occurs when parsing the document.
- *
- * @param eventListener an event listener
- */
- public void setEventListener(EventListener eventListener) {
- this.eventListener = eventListener;
- }
-
- /**
- * Runs FOP on the given document.
- *
- * @param document XSL-FO document to parse
- * @throws FOPException if an error occurs when initializing FOP
- * @throws LoadingException if an error occurs when parsing the document
- */
- public void parse(InputStream document) throws FOPException, LoadingException {
- FOUserAgent foUserAgent = createFOUserAgent();
- fop = FOP_FACTORY.newFop(foUserAgent);
- createTransformer();
- runTransformer(document);
- }
-
- private FOUserAgent createFOUserAgent() {
- FOUserAgent userAgent = FOP_FACTORY.newFOUserAgent();
- FOEventHandler foEventHandler = foEventHandlerFactory.newFOEventHandler(userAgent);
- userAgent.setFOEventHandlerOverride(foEventHandler);
- if (eventListener != null) {
- userAgent.getEventBroadcaster().addEventListener(eventListener);
- }
- return userAgent;
- }
-
- private void createTransformer() {
- try {
- transformer = TRANSFORMER_FACTORY.newTransformer();
- } catch (TransformerConfigurationException e) {
- throw new RuntimeException(e);
- }
- }
-
- private void runTransformer(InputStream input) throws LoadingException, FOPException {
- Source source = new StreamSource(input);
- Result result = new SAXResult(fop.getDefaultHandler());
- try {
- transformer.transform(source, result);
- } catch (TransformerException e) {
- Throwable cause = e.getCause();
- throw new LoadingException(cause == null ? e : cause);
- }
- }
- }
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