Java操作FreeMarker模板引擎的基本用法示例小结

public void process(String template, Map<String, ?> data) throws Exception {

   Configuration cfg = new Configuration();

   cfg.setDirectoryForTemplateLoading( new File( "ftl" ));

   cfg.setObjectWrapper( new DefaultObjectWrapper());

   //设置字符集

   cfg.setDefaultEncoding( "UTF-8" );

   //设置尖括号语法和方括号语法,默认是自动检测语法

   // 自动 AUTO_DETECT_TAG_SYNTAX

   // 尖括号 ANGLE_BRACKET_TAG_SYNTAX

   // 方括号 SQUARE_BRACKET_TAG_SYNTAX

   cfg.setTagSyntax(Configuration.AUTO_DETECT_TAG_SYNTAX);

   Writer out = new OutputStreamWriter( new FileOutputStream(FILE_DIR + template + ".txt" ), "UTF-8" );

   Template temp = cfg.getTemplate(template);

   temp.process(data, out);

   out.flush();

}

< html >

  < head >

     < title >freemarker测试</ title >

   </ head >

   < body >

     < h1 >${message},${name}</ h1 >

   </ body >

</ html >

package com.test.servlet;

import java.io.IOException;

import java.io.Writer;

import java.util.HashMap;

import java.util.Map;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import freemarker.template.Configuration;

import freemarker.template.Template;

import freemarker.template.TemplateException;

@SuppressWarnings ( "serial" )

public class HelloFreeMarkerServlet extends HttpServlet {

   // 负责管理FreeMarker模板的Configuration实例

   private Configuration cfg = null ;

   public void init() throws ServletException {

     // 创建一个FreeMarker实例

     cfg = new Configuration();

     // 指定FreeMarker模板文件的位置

     cfg.setServletContextForTemplateLoading(getServletContext(),

         "/WEB-INF/templates" );

   }

   @SuppressWarnings ( "unchecked" )

   public void doPost(HttpServletRequest request, HttpServletResponse response)

       throws ServletException, IOException {

     // 建立数据模型

     Map root = new HashMap();

     root.put( "message" , "hello world" );

     root.put( "name" , "java小强" );

     // 获取模板文件

     Template t = cfg.getTemplate( "test.ftl" );

     // 使用模板文件的Charset作为本页面的charset

     // 使用text/html MIME-type

     response.setContentType( "text/html; charset=" + t.getEncoding());

     Writer out = response.getWriter();

     // 合并数据模型和模板，并将结果输出到out中

     try {

       t.process(root, out); // 往模板里写数据

     } catch (TemplateException e) {

       e.printStackTrace();

     }

   }

   public void doGet(HttpServletRequest request, HttpServletResponse response)

       throws ServletException, IOException {

     doPost(request, response);

   }

   public void destroy() {

     super .destroy();

   }

}

<? xml version = "1.0" encoding = "UTF-8" ?>

< web-app version = "2.5" xmlns = "http://java.sun测试数据/xml/ns/javaee"

   xmlns:xsi = "http://HdhCmsTestw3.org/2001/XMLSchema-instance"

   xsi:schemaLocation="http://java.sun测试数据/xml/ns/javaee 

   http://java.sun测试数据/xml/ns/javaee/web-app_2_5.xsd">

   < servlet >

     < servlet-name >hello</ servlet-name >

     < servlet-class >

       com.test.servlet.HelloFreeMarkerServlet

     </ servlet-class >

   </ servlet >

   < servlet-mapping >

     < servlet-name >hello</ servlet-name >

     < url-pattern >/hello</ url-pattern >

   </ servlet-mapping >

   < welcome-file-list >

     < welcome-file >index.jsp</ welcome-file >

   </ welcome-file-list >

</ web-app >

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()

+":"+request.getServerPort()+path+"/";

%>

< html >

  < body >

   <%

   String mypath = "hello";

   response.sendRedirect(basePath + mypath);

   %>

  </ body >

</ html >

<#-- 1、算术运算 -->[BR]

${3 + 4}

<#-- 2、内建函数 -->[BR]

${"rensanning"?upper_case}

HashMap t2root = new HashMap<String, String>();

t2root.put("user", "RenSanNing");

${user}, Welcome!

Map<String, Object> t3root = new HashMap<String, Object>();

List<Food> menu = new ArrayList<Food>();

menu.add(new Food("iText in Action", 98));

menu.add(new Food("iBATIS in Action", 118));

menu.add(new Food("Lucene in Action", 69));

t3root.put("menu", menu);

<#list menu as food>

${food.name} ${food.price?string.currency}

</#list>

Map<String, Object> t4root = new HashMap<String, Object>();

t4root.put( "x" , 2 );

t4root.put( "y" , "medium" );

<1>if, else, elseif:

<#if x == 1>

  x is 1

<#elseif x == 2>

  x is 2

<#elseif x == 3>

  x is 3

<#elseif x == 4>

  x is 4

<#else>

  x is not 1 nor 2 nor 3 nor 4

</#if>

<2>switch, case, default, break:

<#switch y>

  <#case "small">

    This will be processed if it is small

    <#break>

  <#case "medium">

    This will be processed if it is medium

    <#break>

  <#case "large">

    This will be processed if it is large

    <#break>

  <#default>

    This will be processed if it is neither

</#switch>

<3>list, break:

<#assign seq = ["winter", "spring", "summer", "autumn"]>

<#list seq as x>

  ${x_index + 1}. ${x}<#if x_has_next>,</#if>

</#list>

<#function fact n>

  <#if n == 0>

   <#return 1 />

  <#else>

   <#return fact(n - 1) * n />

  </#if>

</#function>

<#list 0..10 as i>

  ${i}! => ${fact(i)}

</#list>

<#-- 1、本地变量 -->[BR]

<#function partg n lst>

  <#local ans = []>

  <#list lst as x>

   <#if (x >= n)>

    <#local ans = ans + [x]>

   </#if>

  </#list>

  <#return ans>

</#function>

<#assign ls = [10, 2, 4, 5, 8, 1, 3]>

<#list partg(4, ls) as x>${x} </#list>

<#-- 2、变量域测试 -->[BR]

<#macro test>

   03. ${x}

   <#global x = "global2">

   04. ${x}

   <#assign x = "assign2">

   05. ${x}

   <#local x = "local1">

   06. ${x}

   <#list ["循环1"] as x>

     07. ${x}

     <#local x = "local2">

     08. ${x}

     <#assign x = "assign3">

     09. ${x}

   </#list>

   10. ${x}

</#macro>

<#global x = "global1" />

01. ${x}

<#assign x = "assign1" />

02. ${x}

<@test />

11. ${x}

<#-- 1、无参数 -->[BR]

<#macro greet>

Welcome!

</#macro>

<@greet />

<#-- 2、有参数 -->[BR]

<#macro greet user>

${user}, Welcome!

</#macro>

<@greet user="RenSanNing"/>

<#-- 3、有多个参数 -->[BR]

<#macro table cols rows>

  <table>

   <#list 1..rows as row>

    <tr>

     <#list 1..cols as col>

      <td>${row}, ${col}</td>

     </#list>

    </tr>

   </#list>

  </table>

</#macro>

<@table cols=3 rows=2 />

<#-- 4、中间跳出 -->[BR]

<#macro out>

  显示文字

  <#return>

  不显示文字

</#macro>

<@out />

<#-- 5、嵌套 -->[BR]

<#macro lprint lst>

  <#list lst as item>

  ?${item}<#nested item />

  </#list>

</#macro>

<@lprint 1..3; x>^2 = ${x * x}</@lprint>

<@lprint 1..3; x>^3 = ${x * x * x}</@lprint>

<@lprint ["Let's go", "to the", "land of Medetai"] />

<#include "T108include.ftl">

${url}

<@greet name="rensanning" />

<#macro greet name>

${name}, Welcome!

</#macro>

<#assign url="http://HdhCmsTestbaidu测试数据/">

<#import "T109include.ftl" as my>

<#assign url="http://HdhCmsTestgoogle测试数据/">

${my.url}

<@my.greet name="rensanning" />

${url}

<#macro greet name>

${name}, Welcome!

</#macro>

<#assign url="http://HdhCmsTestbaidu测试数据/">

public class SystemDateDirective implements TemplateDirectiveModel {

   public void execute(Environment env, Map params, TemplateModel[] loopVars,

       TemplateDirectiveBody body) throws TemplateException, IOException {

     Calendar cal = Calendar.getInstance();

     SimpleDateFormat sdf = new SimpleDateFormat( "yyyy/MM/dd HH:mm:ss" );

     env.getOut().append(sdf.format(cal.getTime()));

   }

}

public class TextCutDirective implements TemplateDirectiveModel {

   public static final String PARAM_S = "s" ;

   public static final String PARAM_LEN = "len" ;

   public static final String PARAM_APPEND = "append" ;

   @SuppressWarnings ( "unchecked" )

   public void execute(Environment env, Map params, TemplateModel[] loopVars,

       TemplateDirectiveBody body) throws TemplateException, IOException {

     String s = getString(PARAM_S, params);

     Integer len = getInt(PARAM_LEN, params);

     String append = getString(PARAM_APPEND, params);

     if (s != null ) {

       Writer out = env.getOut();

       if (len != null ) {

         out.append(textCut(s, len, append));

       } else {

         out.append(s);

       }

     }

   }

Map<String, Object> t10root = new HashMap<String, Object>();

t10root.put( "systemdate" , new SystemDateDirective());

t10root.put( "text_cut" , new TextCutDirective());