Java tutorial
/* * 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: AFPExtensionHandler.java 1095882 2011-04-22 07:44:46Z jeremias $ */ package org.apache.fop.render.afp.extensions; import java.net.URI; import java.net.URISyntaxException; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.AttributesImpl; import org.xml.sax.helpers.DefaultHandler; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.fop.render.afp.extensions.AFPPageSegmentElement.AFPPageSegmentSetup; import org.apache.fop.util.ContentHandlerFactory; import org.apache.fop.util.ContentHandlerFactory.ObjectBuiltListener; /** * ContentHandler (parser) for restoring AFPExtension objects from XML. */ public class AFPExtensionHandler extends DefaultHandler implements ContentHandlerFactory.ObjectSource { /** Logger instance */ protected static final Log log = LogFactory.getLog(AFPExtensionHandler.class); private StringBuffer content = new StringBuffer(); private Attributes lastAttributes; private AFPExtensionAttachment returnedObject; private ObjectBuiltListener listener; /** {@inheritDoc} */ @Override public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { boolean handled = false; if (AFPExtensionAttachment.CATEGORY.equals(uri)) { lastAttributes = new AttributesImpl(attributes); handled = true; if (localName.equals(AFPElementMapping.NO_OPERATION) || localName.equals(AFPElementMapping.TAG_LOGICAL_ELEMENT) || localName.equals(AFPElementMapping.INCLUDE_PAGE_OVERLAY) || localName.equals(AFPElementMapping.INCLUDE_PAGE_SEGMENT) || localName.equals(AFPElementMapping.INCLUDE_FORM_MAP) || localName.equals(AFPElementMapping.INVOKE_MEDIUM_MAP)) { //handled in endElement } else { handled = false; } } if (!handled) { if (AFPExtensionAttachment.CATEGORY.equals(uri)) { throw new SAXException("Unhandled element " + localName + " in namespace: " + uri); } else { log.warn("Unhandled element " + localName + " in namespace: " + uri); } } } /** {@inheritDoc} */ @Override public void endElement(String uri, String localName, String qName) throws SAXException { if (AFPExtensionAttachment.CATEGORY.equals(uri)) { if (AFPElementMapping.INCLUDE_FORM_MAP.equals(localName)) { AFPIncludeFormMap formMap = new AFPIncludeFormMap(); String name = lastAttributes.getValue("name"); formMap.setName(name); String src = lastAttributes.getValue("src"); try { formMap.setSrc(new URI(src)); } catch (URISyntaxException e) { throw new SAXException("Invalid URI: " + src, e); } this.returnedObject = formMap; } else if (AFPElementMapping.INCLUDE_PAGE_OVERLAY.equals(localName)) { this.returnedObject = new AFPPageOverlay(); String name = lastAttributes.getValue("name"); if (name != null) { returnedObject.setName(name); } } else if (AFPElementMapping.INCLUDE_PAGE_SEGMENT.equals(localName)) { AFPPageSegmentSetup pageSetupExtn = null; pageSetupExtn = new AFPPageSegmentSetup(localName); this.returnedObject = pageSetupExtn; String name = lastAttributes.getValue("name"); if (name != null) { returnedObject.setName(name); } String value = lastAttributes.getValue("value"); if (value != null && pageSetupExtn != null) { pageSetupExtn.setValue(value); } String resourceSrc = lastAttributes.getValue("resource-file"); if (resourceSrc != null && pageSetupExtn != null) { pageSetupExtn.setResourceSrc(resourceSrc); } if (content.length() > 0 && pageSetupExtn != null) { pageSetupExtn.setContent(content.toString()); content.setLength(0); //Reset text buffer (see characters()) } } else { AFPPageSetup pageSetupExtn = null; if (AFPElementMapping.INVOKE_MEDIUM_MAP.equals(localName)) { this.returnedObject = new AFPInvokeMediumMap(); } else { pageSetupExtn = new AFPPageSetup(localName); this.returnedObject = pageSetupExtn; } String name = lastAttributes.getValue(AFPPageSetup.ATT_NAME); if (name != null) { returnedObject.setName(name); } String value = lastAttributes.getValue(AFPPageSetup.ATT_VALUE); if (value != null && pageSetupExtn != null) { pageSetupExtn.setValue(value); } String placement = lastAttributes.getValue(AFPPageSetup.ATT_PLACEMENT); if (placement != null && placement.length() > 0) { pageSetupExtn.setPlacement(ExtensionPlacement.fromXMLValue(placement)); } if (content.length() > 0 && pageSetupExtn != null) { pageSetupExtn.setContent(content.toString()); content.setLength(0); //Reset text buffer (see characters()) } } } } /** {@inheritDoc} */ @Override public void characters(char[] ch, int start, int length) throws SAXException { content.append(ch, start, length); } /** * {@inheritDoc} */ @Override public void endDocument() throws SAXException { if (listener != null) { listener.notifyObjectBuilt(getObject()); } } /** * {@inheritDoc} */ public Object getObject() { return returnedObject; } /** * {@inheritDoc} */ public void setObjectBuiltListener(ObjectBuiltListener listen) { this.listener = listen; } }