001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.processor.cache;
018    
019    import java.io.File;
020    import java.io.InputStream;
021    import java.io.StringReader;
022    
023    import javax.xml.transform.Source;
024    import javax.xml.transform.Transformer;
025    import javax.xml.transform.TransformerFactory;
026    import javax.xml.transform.dom.DOMResult;
027    import javax.xml.transform.dom.DOMSource;
028    
029    import org.w3c.dom.Document;
030    
031    import net.sf.ehcache.CacheManager;
032    import net.sf.ehcache.Ehcache;
033    import org.apache.camel.Exchange;
034    import org.apache.camel.Processor;
035    import org.apache.camel.component.cache.factory.CacheManagerFactory;
036    import org.apache.camel.converter.IOConverter;
037    import org.apache.camel.converter.jaxp.XmlConverter;
038    import org.apache.camel.util.ObjectHelper;
039    import org.apache.commons.logging.Log;
040    import org.apache.commons.logging.LogFactory;
041    
042    public class CacheBasedXPathReplacer extends CacheValidate implements Processor {
043        private static final transient Log LOG = LogFactory.getLog(CacheBasedXPathReplacer.class);
044        private String cacheName;
045        private String key;
046        private String xpath;
047        private CacheManager cacheManager;
048        private Ehcache cache;
049        private Document document;
050        private DOMSource source;
051        private DOMResult result;
052    
053        public CacheBasedXPathReplacer(String cacheName, String key, String xpath) {
054            super();
055            if (cacheName.contains("cache://")) {
056                this.setCacheName(cacheName.replace("cache://", ""));
057            } else {
058                this.setCacheName(cacheName);
059            }
060            this.key = key;
061            this.xpath = xpath;
062        }
063    
064        public void process(Exchange exchange) throws Exception {
065            // Cache the buffer to the specified Cache against the specified key
066            cacheManager = new CacheManagerFactory().instantiateCacheManager();
067    
068            if (isValid(cacheManager, cacheName, key)) {
069                cache = cacheManager.getCache(cacheName);
070    
071                if (LOG.isDebugEnabled()) {
072                    LOG.debug("Replacing XPath value " + xpath + "in Message with value stored against key " + key
073                            + " in CacheName " + cacheName);
074                }
075                exchange.getIn().setHeader("CACHE_KEY", key);
076                Object body = exchange.getIn().getBody();
077                InputStream is = exchange.getContext().getTypeConverter().convertTo(InputStream.class, body);
078                try {
079                    document = exchange.getContext().getTypeConverter().convertTo(Document.class, exchange, is);
080                } finally {
081                    ObjectHelper.close(is, "is", LOG);
082                }
083    
084                InputStream cis = exchange.getContext().getTypeConverter()
085                    .convertTo(InputStream.class, cache.get(key).getObjectValue());
086    
087                try {
088                    Document cacheValueDocument = exchange.getContext().getTypeConverter()
089                        .convertTo(Document.class, exchange, cis);
090    
091                    // Create/setup the Transformer
092                    XmlConverter xmlConverter = new XmlConverter();
093                    String xslString = IOConverter.toString(new File("./src/main/resources/xpathreplacer.xsl"), exchange);
094                    xslString = xslString.replace("##match_token##", xpath);
095                    Source xslSource = xmlConverter.toStreamSource(new StringReader(xslString));
096                    TransformerFactory transformerFactory = xmlConverter.createTransformerFactory();
097                    Transformer transformer = transformerFactory.newTransformer(xslSource);
098                    source = xmlConverter.toSource(document);
099                    result = new DOMResult();
100    
101                    transformer.setParameter("cacheValue", cacheValueDocument);
102                    transformer.transform(source, result);
103                } finally {
104                    ObjectHelper.close(cis, "cis", LOG);
105                }
106            }
107    
108            // DOMSource can be converted to byte[] by camel type converter mechanism
109            DOMSource dom = new DOMSource(result.getNode());
110            exchange.getIn().setBody(dom, byte[].class);
111        }
112    
113        public String getCacheName() {
114            return cacheName;
115        }
116    
117        public void setCacheName(String cacheName) {
118            this.cacheName = cacheName;
119        }
120    
121        public String getKey() {
122            return key;
123        }
124    
125        public void setKey(String key) {
126            this.key = key;
127        }
128    
129        public String getXpath() {
130            return xpath;
131        }
132    
133        public void setXpath(String xpath) {
134            this.xpath = xpath;
135        }
136    
137    }