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.component.stringtemplate;
018    
019    import java.io.StringWriter;
020    import java.util.Map;
021    
022    import org.antlr.stringtemplate.AutoIndentWriter;
023    import org.antlr.stringtemplate.StringTemplate;
024    import org.apache.camel.Exchange;
025    import org.apache.camel.ExchangePattern;
026    import org.apache.camel.Message;
027    import org.apache.camel.Processor;
028    import org.apache.camel.component.ResourceBasedEndpoint;
029    import org.apache.camel.util.ExchangeHelper;
030    
031    /**
032     * @version $Revision: 15729 $
033     */
034    public class StringTemplateEndpoint extends ResourceBasedEndpoint {
035    
036        public StringTemplateEndpoint(String uri, StringTemplateComponent component, String resourceUri, Map parameters) {
037            super(uri, component, resourceUri, null);
038        }
039    
040        public StringTemplateEndpoint(String endpointUri, Processor processor, String resourceUri) {
041            super(endpointUri, processor, resourceUri);
042        }
043    
044        @Override
045        public boolean isSingleton() {
046            return true;
047        }
048    
049        @Override
050        public ExchangePattern getExchangePattern() {
051            return ExchangePattern.InOut;
052        }
053    
054        @Override
055        protected void onExchange(Exchange exchange) throws Exception {
056            StringWriter buffer = new StringWriter();
057            Map variableMap = ExchangeHelper.createVariableMap(exchange);
058    
059            // getResourceAsInputStream also considers the content cache
060            String text = exchange.getContext().getTypeConverter().mandatoryConvertTo(String.class, getResourceAsInputStream());
061            StringTemplate template = new StringTemplate(text);
062            template.setAttributes(variableMap);
063            if (log.isDebugEnabled()) {
064                log.debug("StringTemplate is writing using attributes: " + variableMap);
065            }
066            template.write(new AutoIndentWriter(buffer));
067    
068            // now lets output the results to the exchange
069            Message out = exchange.getOut();
070            out.setBody(buffer.toString());
071            out.setHeader(StringTemplateConstants.STRINGTEMPLATE_RESOURCE, getResource());
072        }
073        
074    }