老調重彈。對SSH經典組合有些膩，不再那么輕，重返到若干年前的原始。
Servlet的輕巧高效，Freemarker的強大簡便，兩者結合將是超輕的組合，即可避免丑陋的Java代碼和HTML代碼雜揉，又可高效基于模板的站點開發。
閑話少說，項目需要：
freemarker-2.3.13.jar
servlet.jar
定義兩個Servlet：
HelloAction.java 對應 /hello,借助Freemarker硬編碼輸出
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 {
// 填充數據類型
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;
}
}
}
對應模板：
<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 對應 /hi ，借助Freemrker Servlet的攔截功能，如以往寫代碼方式，感覺不到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);
}
}
對應的模板：
<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 配置文件中定義如下：
<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>
使用哪一種組合方式，看您喜好了。
借助于Freemarker自身的Servlet工具，只是用于攔截Servlet中forward轉向使用到的HTML資源文件。
很簡陋，但湊合著能看。
項目源代碼已經打包如下：
下載源文件