Java tutorial
/** * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file * distributed with this work for additional information regarding copyright ownership. Apereo * 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 the * following location: * * <p>http://www.apache.org/licenses/LICENSE-2.0 * * <p>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. */ package org.apereo.portal.io.xml; import java.util.List; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.transform.Source; import javax.xml.transform.sax.SAXSource; import org.apereo.portal.spring.spel.IPortalSpELService; import org.apereo.portal.spring.spel.PortalSpELServiceImpl; import org.dom4j.Attribute; import org.dom4j.Document; import org.dom4j.Node; import org.dom4j.io.DocumentSource; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.expression.EvaluationContext; import org.springframework.expression.Expression; /** * Implements a SpEL-based templating strategy. * * @since 4.2 * @author drewwills */ public class SpELDataTemplatingStrategy implements IDataTemplatingStrategy { private static final String ATTRIBUTE_XPATH = "//@*"; private static final String TEXT_XPATH = "//text()"; private static final String[] XPATH_EXPRESSIONS = new String[] { ATTRIBUTE_XPATH, TEXT_XPATH }; private final IPortalSpELService portalSpELService; private final EvaluationContext ctx; private final Logger log = LoggerFactory.getLogger(getClass()); public SpELDataTemplatingStrategy(IPortalSpELService portalSpELService, EvaluationContext ctx) { this.portalSpELService = portalSpELService; this.ctx = ctx; DocumentBuilderFactory fac = DocumentBuilderFactory.newInstance(); fac.setNamespaceAware(true); } @Override public Source processTemplates(Document data, String filename) { log.trace("Processing templates for document XML={}", data.asXML()); for (String xpath : XPATH_EXPRESSIONS) { @SuppressWarnings("unchecked") List<Node> nodes = data.selectNodes(xpath); for (Node n : nodes) { String inpt, otpt; switch (n.getNodeType()) { case org.w3c.dom.Node.ATTRIBUTE_NODE: Attribute a = (Attribute) n; inpt = a.getValue(); otpt = processText(inpt); if (otpt == null) { throw new RuntimeException("Invalid expression '" + inpt + "' in file " + filename); } if (!otpt.equals(inpt)) { a.setValue(otpt); } break; case org.w3c.dom.Node.TEXT_NODE: case org.w3c.dom.Node.CDATA_SECTION_NODE: inpt = n.getText(); otpt = processText(inpt); if (otpt == null) { throw new RuntimeException("Invalid expression '" + inpt + "' in file " + filename); } if (!otpt.equals(inpt)) { n.setText(otpt); } break; default: String msg = "Unsupported node type: " + n.getNodeTypeName(); throw new RuntimeException(msg); } } } final SAXSource rslt = new DocumentSource(data); rslt.setSystemId(filename); // must be set, else import chokes return rslt; } /* * Implementation */ private String processText(String text) { String rslt = text; // default Expression x = portalSpELService.parseExpression(text, PortalSpELServiceImpl.TemplateParserContext.INSTANCE); rslt = x.getValue(ctx, String.class); return rslt; } }