/**
* 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.
*/
package org.apache.camel.component.velocity;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.util.Map;
import org.apache.camel.Exchange;
import org.apache.camel.ExchangePattern;
import org.apache.camel.Message;
import org.apache.camel.component.ResourceBasedEndpoint;
import org.apache.camel.util.ExchangeHelper;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.context.Context;
/**
* @version $Revision: 641680 $
*/
public class VelocityEndpoint extends ResourceBasedEndpoint {
private final VelocityComponent component;
private VelocityEngine velocityEngine;
public VelocityEndpoint(String uri, VelocityComponent component, String resourceUri, Map parameters) {
super(uri, component, resourceUri, null);
this.component = component;
}
public boolean isSingleton() {
return true;
}
@Override
public ExchangePattern getExchangePattern() {
return ExchangePattern.InOut;
}
public VelocityEngine getVelocityEngine() throws Exception {
if (velocityEngine == null) {
velocityEngine = component.getVelocityEngine();
velocityEngine.init();
}
return velocityEngine;
}
public void setVelocityEngine(VelocityEngine velocityEngine) {
this.velocityEngine = velocityEngine;
}
@Override
protected void onExchange(Exchange exchange) throws Exception {
// TODO we might wanna add some kinda resource caching of the template
Reader reader = new InputStreamReader(getResource().getInputStream());
StringWriter buffer = new StringWriter();
String logTag = getClass().getName();
Map variableMap = ExchangeHelper.createVariableMap(exchange);
Context velocityContext = new VelocityContext(variableMap);
VelocityEngine engine = getVelocityEngine();
engine.evaluate(velocityContext, buffer, logTag, reader);
// now lets output the results to the exchange
Message out = exchange.getOut(true);
out.setBody(buffer.toString());
out.setHeader("org.apache.camel.velocity.resource", getResource());
}
}