001 /**
002 * Copyright 2005-2012 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016 package org.kuali.rice.ken.util;
017
018 import java.io.StringReader;
019 import java.io.StringWriter;
020 import java.util.HashMap;
021 import java.util.Iterator;
022
023 import javax.xml.transform.ErrorListener;
024 import javax.xml.transform.Source;
025 import javax.xml.transform.Transformer;
026 import javax.xml.transform.TransformerException;
027 import javax.xml.transform.TransformerFactory;
028 import javax.xml.transform.stream.StreamResult;
029 import javax.xml.transform.stream.StreamSource;
030
031 import org.apache.log4j.Logger;
032
033 /**
034 * This class handles XSLT transformations.
035 * @author Kuali Rice Team (rice.collab@kuali.org)
036 */
037 public class ContentTransformer {
038 private static final Logger LOG = Logger.getLogger(ContentTransformer.class);
039
040 private static final class LoggingErrorListener implements ErrorListener {
041 private final ErrorListener delegate;
042 public LoggingErrorListener(ErrorListener delegate) {
043 this.delegate = delegate;
044 }
045
046 public void error(TransformerException exception) throws TransformerException {
047 LOG.error("Error transforming document", exception);
048 }
049
050 public void fatalError(TransformerException exception) throws TransformerException {
051 if (delegate != null) {
052 delegate.fatalError(exception);
053 } else {
054 throw exception;
055 }
056
057 }
058
059 public void warning(TransformerException exception) throws TransformerException {
060 LOG.warn("Error transforming document", exception);
061 }
062
063 };
064
065 private Transformer transformer;
066
067 /**
068 * Constructs a ContentTransformer.java.
069 * @param aStyleSheet
070 * @throws Exception
071 */
072 public ContentTransformer(StreamSource aStyleSheet) throws Exception {
073 // create transformer
074 TransformerFactory factory = TransformerFactory.newInstance();
075 transformer = factory.newTransformer( aStyleSheet );
076 }
077
078 /**
079 * Constructs a ContentTransformer.java.
080 * @param aStyleSheet
081 * @param parametermap
082 * @throws Exception
083 */
084 public ContentTransformer(StreamSource aStyleSheet, HashMap parametermap) throws Exception {
085 // create transformer
086 TransformerFactory factory = TransformerFactory.newInstance();
087 transformer = factory.newTransformer( aStyleSheet );
088 Iterator iter = parametermap.keySet().iterator();
089 while (iter.hasNext()) {
090 Object o = iter.next();
091 String param = o.toString();
092 String value = (String) parametermap.get(param);
093 transformer.setParameter(param, value);
094 }
095 transformer.setErrorListener(new LoggingErrorListener(transformer.getErrorListener()));
096 }
097
098 /**
099 * This method performs the actual transformation.
100 * @param xml
101 * @return
102 * @throws Exception
103 */
104 public String transform(String xml) throws Exception {
105
106 // perform transformation
107 Source xmlsource = new StreamSource(new StringReader(xml));
108 StringWriter sout = new StringWriter();
109
110 transformer.transform(xmlsource, new StreamResult(sout));
111
112 // return resulting document
113 return sout.toString();
114 }
115 }