将java版的Velocity翻译成.net版本（一）使用入门

/Files/icoolno1/nvelocity.rar

环境需求：.net framework 4.0

Velocity的流程：

读取模板文件－>解析语法->合并变量执行->输出目标文件

下边是JAVA的示例：

/*
* 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.
*/

import org.apache.velocity.app.Velocity;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.Template;

import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;

import java.io.*;
import java.util.ArrayList;

/**
* This class is a simple demonstration of how the Velocity Template Engine
* can be used in a standalone application.
*
* @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
* @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
* @version $Id: Example.java 463298 2006-10-12 16:10:32Z henning $
*/

public class Example
{
public Example(String templateFile)
{
try
{
/*
* setup
*/

Velocity.init("velocity.properties");

/*
* 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();
context.put("list", getNames());

/*
* 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 = null;

try
{
template = Velocity.getTemplate(templateFile);//获取模板
}
catch( ResourceNotFoundException rnfe )
{
System.out.println("Example : error : cannot find template " + templateFile );
}
catch( ParseErrorException pee )
{
System.out.println("Example : Syntax error in template " + templateFile + ":" + pee );
}

/*
* 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.
*/

BufferedWriter writer = writer = new BufferedWriter(
new OutputStreamWriter(System.out));

if ( template != null)
template.merge(context, writer); //合并并输出到流

/*
* flush and cleanup
*/

writer.flush();
writer.close();
}
catch( Exception e )
{
System.out.println(e);
}
}

public ArrayList getNames()
{
ArrayList list = new ArrayList();

list.add("ArrayList element 1");
list.add("ArrayList element 2");
list.add("ArrayList element 3");
list.add("ArrayList element 4");

return list;
}

public static void main(String[] args)
{
Example t = new Example(args[0]);
}}

下边是一段C#代码示例：

StreamWriter sw = new StreamWriter(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "o.txt"));

ExtendedProperties props = new ExtendedProperties();
string tplPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "templates");
props.AddProperty("file.resource.loader.path", tplPath);
props.AddProperty("input.encoding", "UTF-8");
props.AddProperty("output.encoding", "UTF-8");
props.AddProperty("velocimacro.library", "VM_global_library.vm");

try
{
Velocity.Init(props);
VelocityContext context = new VelocityContext();
context.Put("test", new Class1());
Template template = Velocity.GetTemplate("t.txt");//获取模板

template.Merge(context, sw);//合并并输出到流
}
catch (Exception ex)
{

}
sw.Flush();
sw.Close();

以上两段基本上相同，主要区别就是加载配置方式不一样，当然这个区别也是两语言之间的差别。