- /*
- * 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.util;
-
- import java.lang.reflect.InvocationTargetException;
- import java.util.Iterator;
- import java.util.Map;
-
- import org.apache.commons.logging.Log;
- import org.apache.commons.logging.LogFactory;
-
- import org.apache.xmlgraphics.util.Service;
-
- /**
- * This class holds references to various XML handlers used by FOP. It also
- * supports automatic discovery of additional XML handlers available through
- * the class path.
- */
- public class ContentHandlerFactoryRegistry {
-
- /** the logger */
- private static Log log = LogFactory.getLog(ContentHandlerFactoryRegistry.class);
-
- /** Map from namespace URIs to ContentHandlerFactories */
- private Map factories = new java.util.HashMap();
-
- /**
- * Default constructor.
- */
- public ContentHandlerFactoryRegistry() {
- discover();
- }
-
- /**
- * Add an XML handler. The handler itself is inspected to find out what it supports.
- * @param classname the fully qualified class name
- */
- public void addContentHandlerFactory(String classname) {
- try {
- ContentHandlerFactory factory
- = (ContentHandlerFactory)Class.forName(classname).getDeclaredConstructor().newInstance();
- addContentHandlerFactory(factory);
- } catch (ClassNotFoundException e) {
- throw new IllegalArgumentException("Could not find "
- + classname);
- } catch (InstantiationException e) {
- throw new IllegalArgumentException("Could not instantiate "
- + classname);
- } catch (IllegalAccessException e) {
- throw new IllegalArgumentException("Could not access "
- + classname);
- } catch (ClassCastException e) {
- throw new IllegalArgumentException(classname
- + " is not an "
- + ContentHandlerFactory.class.getName());
- } catch (NoSuchMethodException e) {
- throw new IllegalArgumentException(e);
- } catch (InvocationTargetException e) {
- throw new IllegalArgumentException(e);
- }
- }
-
- /**
- * Add an ContentHandlerFactory. The instance is inspected to find out what it supports.
- * @param factory the ContentHandlerFactory instance
- */
- public void addContentHandlerFactory(ContentHandlerFactory factory) {
- String[] ns = factory.getSupportedNamespaces();
- for (String n : ns) {
- factories.put(n, factory);
- }
- }
-
- /**
- * Retrieves a ContentHandlerFactory instance of a given namespace URI.
- * @param namespaceURI the namespace to be handled.
- * @return the ContentHandlerFactory or null, if no suitable instance is available.
- */
- public ContentHandlerFactory getFactory(String namespaceURI) {
- ContentHandlerFactory factory = (ContentHandlerFactory)factories.get(namespaceURI);
- return factory;
- }
-
- /**
- * Discovers ContentHandlerFactory implementations through the classpath and dynamically
- * registers them.
- */
- private void discover() {
- // add mappings from available services
- Iterator providers = Service.providers(ContentHandlerFactory.class);
- if (providers != null) {
- while (providers.hasNext()) {
- ContentHandlerFactory factory = (ContentHandlerFactory)providers.next();
- try {
- if (log.isDebugEnabled()) {
- log.debug("Dynamically adding ContentHandlerFactory: "
- + factory.getClass().getName());
- }
- addContentHandlerFactory(factory);
- } catch (IllegalArgumentException e) {
- log.error("Error while adding ContentHandlerFactory", e);
- }
-
- }
- }
- }
- }
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