/*
* $Id: VelocityTemplateEngine.java 651946 2008-04-27 13:41:38Z apetrelli $
*
* 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.struts2.components.template;
import java.io.IOException;
import java.io.Writer;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.views.velocity.VelocityManager;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.context.Context;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
/**
* Velocity based template engine.
*/
public class VelocityTemplateEngine extends BaseTemplateEngine {
private static final Logger LOG = LoggerFactory.getLogger(VelocityTemplateEngine.class);
private VelocityManager velocityManager;
@Inject
public void setVelocityManager(VelocityManager mgr) {
this.velocityManager = mgr;
}
public void renderTemplate(TemplateRenderingContext templateContext) throws Exception {
// get the various items required from the stack
Map actionContext = templateContext.getStack().getContext();
ServletContext servletContext = (ServletContext) actionContext.get(ServletActionContext.SERVLET_CONTEXT);
HttpServletRequest req = (HttpServletRequest) actionContext.get(ServletActionContext.HTTP_REQUEST);
HttpServletResponse res = (HttpServletResponse) actionContext.get(ServletActionContext.HTTP_RESPONSE);
// prepare velocity
velocityManager.init(servletContext);
VelocityEngine velocityEngine = velocityManager.getVelocityEngine();
// get the list of templates we can use
List<Template> templates = templateContext.getTemplate().getPossibleTemplates(this);
// find the right template
org.apache.velocity.Template template = null;
String templateName = null;
Exception exception = null;
for (Template t : templates) {
templateName = getFinalTemplateName(t);
try {
// try to load, and if it works, stop at the first one
template = velocityEngine.getTemplate(templateName);
break;
} catch (IOException e) {
if (exception == null) {
exception = e;
}
}
}
if (template == null) {
LOG.error("Could not load template " + templateContext.getTemplate());
if (exception != null) {
throw exception;
} else {
return;
}
}
if (LOG.isDebugEnabled()) {
LOG.debug("Rendering template " + templateName);
}
Context context = velocityManager.createContext(templateContext.getStack(), req, res);
Writer outputWriter = templateContext.getWriter();
context.put("tag", templateContext.getTag());
context.put("parameters", templateContext.getParameters());
template.merge(context, outputWriter);
}
protected String getSuffix() {
return "vm";
}
}
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