第1章 FreeMarker快速入门

1-1 模板引擎与Freemarker
◆ 模板引擎的目标是“数据 + 模板 = 结果”
◆ 模板引擎将数据与展现有效“解耦”

主流模板引擎
◆ Java Server Page
◆ Freemarker
◆ Beetl

Freemarker
◆ Freemarker是免费开源的模板引擎技术
◆ Freemarker脚本为Freemarker Template Language
◆ Freemarker提供了大量的内建函数来简化开发

1-2 Freemarker快速上手
Freemarker.
项目中添加 freemarker.jar
创建类：FreemarkerSample1.java
创建File:sample1.ftl(Freemarker的模板文件)
首次创建，提示安装编辑器，Freemarker IDE from JBoss Tools 1.5

${site}-${url}

FreemarkerSample1.java

public class FreemarkerSample1 {public static void main(String[] args)throws TemplateNotFoundException, MalformedTemplateNameException, ParseException, IOException,TemplateException {// 1.加载模版// 创建核心配置对象Configuration config = new Configuration(Configuration.VERSION_2_3_30);// 设置加载的目录config.setClassForTemplateLoading(FreemarkerSample1.class, "");// 得到模板对象Template t = config.getTemplate("sample1.ftl");// 2.创建数据Map<String, Object> data = new HashMap<String, Object>();data.put("site", "百度");data.put("url", "http://www.baidu.com");// 3.产生输出t.process(data, new OutputStreamWriter(System.out));}}

第2章 FreeMarker基本语法

2-1 FTL取值
${属性名}取值，可对属性进行计算
${属性名!默认值}使用默认值
${属性名?string}格式化输出

		data.put("date", new Date());data.put("number", 8345271.897251);Map info = new HashMap();info.put("cpu", "i5");Computer c1 = new Computer("1234567" , "ThinkPad" , 1 , "李四" , new Date() , 12900f , info);data.put("computer", c1);

${date?string("yyyyMMdd")}
${number?string("0.00")}SN:${computer.sn}
型号:${computer.model}
状态:${computer.state}
用户:${computer.user}
采购时间:${computer.dop?string("yyyy年MM月dd日")}
采购价格:${computer.price?string("0.00")}
配置信息:
--------------
CPU:${computer.info["cpu"]}
内存:${computer.info["memory"]!"无内存信息"}

2-2 分支判断

<#if computer.sn == "1234567">
重要设备
</#if>
SN:${computer.sn}
型号:${computer.model}
<#if computer.state == 1>
状态:正在使用
<#elseif computer.state == 2>
状态:闲置
<#elseif computer.state == 3>
状态:已作废
</#if>
<#switch computer.state><#case 1>状态:正在使用<#break><#case 2>状态:闲置<#break><#case 3>状态:已作废<#break><#default>状态:无效状态
</#switch>
<#-- ??代表判断对象是否为空,true不为空,false为空 -->
<#if computer.user??>
用户:${computer.user}
</#if>
采购时间:${computer.dop?string("yyyy年MM月dd日")}
采购价格:${computer.price?string("0.00")}
配置信息:
--------------
CPU:${computer.info["cpu"]}
内存:${computer.info["memory"]!"无内存信息"}

2-3 list迭代列表

		List<Computer> computers = new ArrayList();computers.add(new Computer("1234567" , "ThinkPad X1" , 2 , null , new Date() , 12999f , new HashMap() ));computers.add(new Computer("1234568" , "HP XXX" , 1 , "张三" , new Date() , 7500f , new HashMap() ));computers.add(new Computer("1234569" , "DELL XXX" , 3 , "李四" , new Date() , 8500f , new HashMap() ));computers.add(new Computer("1234570" , "ACER XXX" , 1 , "王五" , new Date() , 6300f , new HashMap() ));computers.add(new Computer("1234571" , "MSI XXX" , 1 , "赵六" , new Date() , 9300f , new HashMap() ));	data.put("computers", computers);

<#list computers as c><#-- 迭代变量_index保存了循环的索引,从0开始 -->
序号:${c_index + 1}
SN:${c.sn}
型号:${c.model}
<#switch c.state>
<#case 1>
状态:使用中
<#break>
<#case 2>
状态:闲置
<#break>
<#case 3>
状态:已作废
<#break>
</#switch>
<#if c.user??>
用户:${c.user}
</#if>
采购日期:${c.dop?string("yyyy-MM-dd")}
采购价格:${c.price?string("0.00")}
-------------------------------------------
</#list>

2-4 list迭代Map

	//LinkedHashMap可以保证数据按存放顺序进行提取Map computerMap = new LinkedHashMap();for(Computer c : computers) {computerMap.put(c.getSn(), c);}data.put("computer_map", computerMap);

<#list computer_map?keys as k >
${k}-${computer_map[k].model}
${computer_map[k].price?string("0.00")}
</#list>

第3章 FreeMarker内建函数

3-1 Freemarker内建函数

		data.put("name", "jackson");data.put("brand", "bmw");data.put("words", "first blood");data.put("n", 37981.83);data.put("date", new Date());List<Computer> computers = new ArrayList();computers.add(new Computer("1234567" , "ThinkPad X1" , 2 , null , new Date() , 12999f , new HashMap() ));computers.add(new Computer("1234568" , "HP XXX" , 1 , "张三" , new Date() , 7500f , new HashMap() ));computers.add(new Computer("1234569" , "DELL XXX" , 3 , "李四" , new Date() , 8500f , new HashMap() ));computers.add(new Computer("1234570" , "ACER XXX" , 1 , "王五" , new Date() , 6300f , new HashMap() ));computers.add(new Computer("1234571" , "MSI XXX" , 1 , "赵六" , new Date() , 9300f , new HashMap() ));	data.put("computers", computers);

${name?cap_first}
${brand?upper_case}
${brand?length}
${words?replace("blood" , "*****")}
${words?index_of("blood")}
<#-- 利用?string实现三目运算符的操作 -->
${(words?index_of("blood") != -1)?string("包含敏感词汇","不包含敏感词汇")}${n?round}
${n?floor}
${n?ceiling}公司共有${computers?size}台电脑
第一台:${computers?first.model}
最后一台:${computers?last.model}<#-- reverse反转 -->
<#list computers?sort_by("price")?reverse as c>${c.sn}-${c.price}
</#list>

freemarker中文参考手册网址: Freemarker.

第4章 FreeMarker与Servlet整合

4-1 Freemarker与Servlet整合
创建项目Dynamic Web Project：fm-web


WebContent/WEB-INF/lib添加jar包：freemarker.jar


配置web.xml

	<servlet><servlet-name>freemarker</servlet-name><servlet-class>freemarker.ext.servlet.FreemarkerServlet</servlet-class><init-param><param-name>TemplatePath</param-name><param-value>/WEB-INF/ftl</param-value></init-param></servlet><servlet-mapping><servlet-name>freemarker</servlet-name><url-pattern>*.ftl</url-pattern></servlet-mapping>

WebContent/WEB-INF/下创建ftl文件夹，存放ftl文件

静态资源下载（css，fonts，js，html）： 下载地址.

创建类：Employee

	private Integer empno;private String ename;private String department;private String job;private Float salary;

创建Servlet

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {List list = new ArrayList();list.add(new Employee(7731,"张三" , "市场部" , "客户代表" , 8000f));list.add(new Employee(8871,"李四" , "研发部" , "运维工程师" , 7000f));request.getServletContext().setAttribute("employee_list", list);request.getRequestDispatcher("/employee.ftl").forward(request, response);}

创建ftl文件：Employee .ftl（将Employee .html内容直接复制进去）

         <#list employee_list as emp><tr><td>${emp_index + 1}</td><td>${emp.empno?string("0")}</td><td>${emp.ename}</td><td>${emp.department}</td><td>${emp.job}</td><td style="color: red;font-weight: bold">￥${emp.salary?string("0.00")}</td></tr></#list>

笔记跟源码来源：慕课网，Java实战课程 链接: 慕课网.