基于 Java 的模板引擎Velocity快速入门

最近使用Velocity模板引擎，写一个maven项目Coding生成工具。

对基于Java的模板引擎Velocity的demo总结如下：

Step1. 创建Maven项目，添加如下velocity的dependency到pom.xml中

  <dependency>
    <groupId>org.apache.velocity</groupId>
    <artifactId>velocity</artifactId>
    <version>1.7</version>
</dependency>

Step2. 创建模板文件HelloVelocity.vm

  #set( $iAmVariable = "good!" )
  Welcome $name to velocity.com
  today is $date.
  $iAmVariable

Step3. 创建Java文件HelloVelocity.java

  package com.bestpay.velocity_demo;
  import java.io.StringWriter;
  import java.util.Date;
  import org.apache.velocity.Template;
  import org.apache.velocity.VelocityContext;
  import org.apache.velocity.app.VelocityEngine;
  import org.apache.velocity.runtime.RuntimeConstants;
  import org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader;

  /**
   * First demo of using velocity
   */
  public class HelloVelocity {  
      public static void main( String[] args ){

          VelocityEngine velocityEngine = new VelocityEngine();
          velocityEngine.setProperty(RuntimeConstants.RESOURCE_LOADER, "classpath");
          velocityEngine.setProperty("classpath.resource.loader.class", ClasspathResourceLoader.class.getName());
          velocityEngine.init();        

          Template template = velocityEngine.getTemplate("com/bestpay/velocity_demo/HelloVelocity.vm", "UTF-8"); 

          VelocityContext context = new VelocityContext();
          context.put("name", "liang01.ma");
          context.put("date", new Date().toString());

          StringWriter writer = new StringWriter();
          template.merge(context, writer);      
          System.out.println(writer.toString());
      }
  }

测试结果

  Welcome liang01.ma to velocity.com
  today is Wed Jul 20 16:57:49 CST 2016.
  good!