组合Servlet+Freemarker的两种方法
Servlet的轻巧高效，Freemarker的强大简便，两者结合将是超轻的组合，即可避免丑陋的Java代码和HTML代码杂揉，又可高效基于模板的站点开发。闲话少说，项目需要：
freemarker-2.3.13.jar
定义两个Servlet：
HelloAction.java 对应 /hello,借助Freemarker硬编码输出
public class HelloAction extends HttpServlet { private static final long serialVersionUID = -6082007726831320176L; private Configuration configuration; public void init() throws ServletException { configuration = new Configuration(); configuration.setServletContextForTemplateLoading(getServletContext(), "WEB-INF/pages"); configuration.setEncoding(Locale.CHINA, "UTF-8"); } @SuppressWarnings("unchecked") public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 填充数据类型 Map map = new HashMap(); map.put("userName", "小敏"); Template template = configuration.getTemplate("hello.html"); response.setContentType("text/html; charset=" + template.getEncoding()); Writer out = response.getWriter(); try{ template.process(map, out); }catch (TemplateException e) { e.printStackTrace(); } } public void destroy() { super.destroy(); if(configuration != null){ configuration = null; } } }?对应模板：
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>使用Freemarker渲染2</title> </head> <body> 你好， $ {userName!} ！ </body> </html>??
HiAction.java 对应 /hi ，借助Freemrker Servlet的拦截功能，如以往写代码方式，感觉不到Freemarker的存在。
public class HiAction extends HttpServlet { private static final long serialVersionUID = 518767483952153077L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setAttribute("thename", "小敏"); request.getRequestDispatcher("/WEB-INF/pages/hi.html").forward(request, response); } }?对应的模板：
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>使用Freemarker渲染</title> </head> <body> hi $ {thename!}~<br /> </body> </html>?但需要在web.xml 配置文件中定义如下：
<servlet> <servlet-name>freemarker</servlet-name> <servlet-class> freemarker.ext.servlet.FreemarkerServlet </servlet-class> <!-- FreemarkerServlet settings: --> <init-param> <param-name>TemplatePath</param-name> <param-value>/</param-value> </init-param> <init-param> <param-name>NoCache</param-name> <param-value>true</param-value> </init-param> <init-param> <param-name>ContentType</param-name> <param-value>text/html; charset=UTF-8</param-value> <!-- Forces UTF-8 output encoding! --> </init-param> <!-- FreeMarker settings: --> <init-param> <param-name>template_update_delay</param-name> <param-value>0</param-value><!-- 0 is for development only! Use higher value otherwise. --> </init-param> <init-param> <param-name>default_encoding</param-name> <param-value>UTF-8</param-value><!-- The encoding of the template files. --> </init-param> <init-param> <param-name>number_format</param-name> <param-value>0.##########</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet><servlet-mapping> <servlet-name>freemarker</servlet-name> <url-pattern>*.html</url-pattern> </servlet-mapping>?
使用哪一种组合方式，看您喜好了。
借助于Freemarker自身的Servlet工具，只是用于拦截Servlet中forward转向使用到的HTML资源文件。
很简陋，但凑合着能看。