/**
* Copyright (c) 2011-2013, James Zhan 詹波 (jfinal@126.com).
*
* Licensed 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 com.jfinal.render;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.Map.Entry;
import java.util.Iterator;
import java.util.Properties;
import java.util.Set;
import javax.servlet.ServletContext;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.Velocity;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
/**
* VelocityRender.
*/
public class VelocityRender extends Render {
private static final long serialVersionUID = 1012573049421601960L;
private transient static final String encoding = getEncoding();
private transient static final String contentType = "text/html;charset=" + encoding;
private transient static final Properties properties = new Properties();
private transient static boolean notInit = true;
public VelocityRender(String view) {
this.view = view;
}
/*
static {
String webPath = RenderFactory.getServletContext().getRealPath("/");
Properties properties = new Properties();
properties.setProperty(Velocity.FILE_RESOURCE_LOADER_PATH, webPath);
properties.setProperty(Velocity.ENCODING_DEFAULT, encoding);
properties.setProperty(Velocity.INPUT_ENCODING, encoding);
properties.setProperty(Velocity.OUTPUT_ENCODING, encoding);
Velocity.init(properties); // Velocity.init("velocity.properties"); // setup
}*/
static void init(ServletContext servletContext) {
String webPath = servletContext.getRealPath("/");
properties.setProperty(Velocity.FILE_RESOURCE_LOADER_PATH, webPath);
properties.setProperty(Velocity.ENCODING_DEFAULT, encoding);
properties.setProperty(Velocity.INPUT_ENCODING, encoding);
properties.setProperty(Velocity.OUTPUT_ENCODING, encoding);
}
public static void setProperties(Properties properties) {
Set<Entry<Object, Object>> set = properties.entrySet();
for (Iterator<Entry<Object, Object>> it=set.iterator(); it.hasNext();) {
Entry<Object, Object> e = it.next();
VelocityRender.properties.put(e.getKey(), e.getValue());
}
}
public void render() {
if (notInit) {
Velocity.init(properties); // Velocity.init("velocity.properties"); // setup
notInit = false;
}
PrintWriter writer = null;
try {
/*
* Make a context object and populate with the data. This
* is where the Velocity engine gets the data to resolve the
* references (ex. $list) in the template
*/
VelocityContext context = new VelocityContext();
// Map root = new HashMap();
for (Enumeration<String> attrs=request.getAttributeNames(); attrs.hasMoreElements();) {
String attrName = attrs.nextElement();
context.put(attrName, request.getAttribute(attrName));
}
/*
* get the Template object. This is the parsed version of your
* template input file. Note that getTemplate() can throw
* ResourceNotFoundException : if it doesn't find the template
* ParseErrorException : if there is something wrong with the VTL
* Exception : if something else goes wrong (this is generally
* indicative of as serious problem...)
*/
Template template = Velocity.getTemplate(view);
/*
* Now have the template engine process your template using the
* data placed into the context. Think of it as a 'merge'
* of the template and the data to produce the output stream.
*/
response.setContentType(contentType);
writer = response.getWriter(); // BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out));
template.merge(context, writer);
writer.flush(); // flush and cleanup
}
catch(ResourceNotFoundException e) {
throw new RenderException("Example : error : cannot find template " + view, e);
}
catch( ParseErrorException e) {
throw new RenderException("Example : Syntax error in template " + view + ":" + e, e);
}
catch(Exception e ) {
throw new RenderException(e);
}
finally {
if (writer != null)
writer.close();
}
}
}