thymeleaf使用详解

蔚落 2022-05-30 08:12 208阅读 0赞

注:只为自己学习保留之用!

thymeleaf 是新一代的模板引擎，在spring4.0中推荐使用thymeleaf来做前端模版引擎。

## thymeleaf介绍 ##

简单说， Thymeleaf 是一个跟 Velocity、FreeMarker 类似的模板引擎，它可以完全替代 JSP 。相较与其他的模板引擎，它有如下三个极吸引人的特点：

*  1.Thymeleaf 在有网络和无网络的环境下皆可运行，即它可以让美工在浏览器查看页面的静态效果，也可以让程序员在服务器查看带数据的动态页面效果。这是由于它支持 html 原型，然后在 html 标签里增加额外的属性来达到模板+数据的展示方式。浏览器解释 html 时会忽略未定义的标签属性，所以 thymeleaf 的模板可以静态地运行；当有数据返回到页面时，Thymeleaf 标签会动态地替换掉静态内容，使页面动态显示。
 *  2.Thymeleaf 开箱即用的特性。它提供标准和spring标准两种方言，可以直接套用模板实现JSTL、 OGNL表达式效果，避免每天套模板、该jstl、改标签的困扰。同时开发人员也可以扩展和创建自定义的方言。
 *  3.Thymeleaf 提供spring标准方言和一个与 SpringMVC 完美集成的可选模块，可以快速的实现表单绑定、属性编辑器、国际化等功能。

## 标准表达式语法 ##

它们分为四类：

*  1.变量表达式
 *  2.选择或星号表达式
 *  3.文字国际化表达式
 *  4.URL表达式

### 变量表达式 ###

变量表达式即OGNL表达式或Spring EL表达式(在Spring术语中也叫model attributes)。如下所示：  
`${session.user.name}`

它们将以HTML标签的一个属性来表示：

### 选择(星号)表达式 ###

选择表达式很像变量表达式，不过它们用一个预先选择的对象来代替上下文变量容器(map)来执行，如下：  
` *{customer.name} `

被指定的object由th:object属性定义：

### 文字国际化表达式 ###

文字国际化表达式允许我们从一个外部文件获取区域文字信息(.properties)，用Key索引Value，还可以提供一组参数(可选).

#{main.title}  
        #{message.entrycreated(${entryId})}

可以在模板文件中找到这样的表达式代码：

### URL表达式 ###

URL表达式指的是把一个有用的上下文或回话信息添加到URL，这个过程经常被叫做URL重写。  
` @{/order/list} `  
URL还可以设置参数：  
` @{/order/details(id=${orderId})} `   
相对路径：  
` @{../documents/report} `

让我们看这些表达式：

### 变量表达式和星号表达有什么区别吗？ ###

如果不考虑上下文的情况下，两者没有区别；星号语法评估在选定对象上表达，而不是整个上下文   
什么是选定对象？就是父标签的值，如下：

<div th:object="${session.user}">
        <p>Name: <span th:text="*{firstName}">Sebastian</span>.</p>
        <p>Surname: <span th:text="*{lastName}">Pepper</span>.</p>
        <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p>
      </div>

这是完全等价于：

<div th:object="${session.user}">
    	  <p>Name: <span th:text="${session.user.firstName}">Sebastian</span>.</p>
    	  <p>Surname: <span th:text="${session.user.lastName}">Pepper</span>.</p>
    	  <p>Nationality: <span th:text="${session.user.nationality}">Saturn</span>.</p>
      </div>

当然，美元符号和星号语法可以混合使用：

<div th:object="${session.user}">
    	  <p>Name: <span th:text="*{firstName}">Sebastian</span>.</p>
      	  <p>Surname: <span th:text="${session.user.lastName}">Pepper</span>.</p>
          <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p>
      </div>

### 表达式支持的语法 ###

#### 字面（Literals） ####

*  文本文字（Text literals）: `'one text', 'Another one!',…`
 *  数字文本（Number literals）: `0, 34, 3.0, 12.3,…`
 *  布尔文本（Boolean literals）: `true, false`
 *  空（Null literal）: `null`
 *  文字标记（Literal tokens）: `one, sometext, main,…`

#### 文本操作（Text operations） ####

*  字符串连接(String concatenation): `+`
 *  文本替换（Literal substitutions）: `|The name is ${name}|`

#### 算术运算（Arithmetic operations） ####

*  二元运算符（Binary operators）: `+, -, *, /, %`
 *  减号（单目运算符）Minus sign (unary operator): `-`

#### 布尔操作（Boolean operations） ####

*  二元运算符（Binary operators）:`and, or`
 *  布尔否定（一元运算符）Boolean negation (unary operator):`!, not`

#### 比较和等价(Comparisons and equality) ####

*  比较（Comparators）: `>, <, >=, <= (gt, lt, ge, le)`
 *  等值运算符（Equality operators）:`==, != (eq, ne)`

#### 条件运算符（Conditional operators） ####

*  If-then: `(if) ? (then)`
 *  If-then-else: `(if) ? (then) : (else)`
 *  Default: (value) ?: `(defaultvalue)`

所有这些特征可以被组合并嵌套：

'User is of type ' + (${user.isAdmin()} ? 'Administrator' : (${user.type} ?: 'Unknown'))

## 常用th标签都有那些？ ##

<table style="margin:0px 0px 16px;padding:0px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-spacing:0px;background-color:rgb(255,255,255);width:847.5px;color:rgb(36,41,46);font-size:16px;"> 
 <thead style="margin:0px;padding:0px;"> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <th style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">关键字</th> 
   <th style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">功能介绍</th> 
   <th style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">案例</th> 
  </tr> 
 </thead> 
 <tbody style="margin:0px;padding:0px;"> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:id</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">替换id</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&nbsp;&lt;input th:id="'xxx' + ${collect.id}"/&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:text</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">文本替换</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;p th:text="${collect.description}"&gt;description&lt;/p&gt;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:utext</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">支持html的文本替换</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;p th:utext="${htmlcontent}"&gt;conten&lt;/p&gt;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:object</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">替换对象</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;div th:object="${session.user}"&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:value</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">属性赋值</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;input th:value="${user.name}" /&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:with</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">变量赋值运算</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;div th:with="isEven=${prodStat.count}%2==0"&gt;&lt;/div&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:style</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">设置样式</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">th:style="'display:' + @{(${sitrue} ? 'none' : 'inline-block')} + ''"&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:onclick</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">点击事件</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">th:onclick="'getCollect()'"&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:each</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">属性赋值</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">tr th:each="user,userStat:${users}"&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:if</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">判断条件</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&nbsp;&lt;a th:if="${userId == collect.userId}" &gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:unless</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">和th:if判断相反</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;a th:href="@{/login}" th:unless=${session.user != null}&gt;Login&lt;/a&gt;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:href</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">链接地址</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;a th:href="@{/login}" th:unless=${session.user != null}&gt;Login&lt;/a&gt; /&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:switch</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">多路选择 配合th:case 使用</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;div th:switch="${user.role}"&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:case</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:switch的一个分支</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&nbsp;&lt;p th:case="'admin'"&gt;User is an administrator&lt;/p&gt;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:fragment</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">布局标签，定义一个代码片段，方便其它地方引用</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;div th:fragment="alert"&gt;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:include</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">布局标签，替换内容到引入的文件</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;head th:include="layout :: htmlhead" th:with="title='xx'"&gt;&lt;/head&gt; /&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:replace</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">布局标签，替换整个标签到引入的文件</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;div th:replace="fragments/header :: title"&gt;&lt;/div&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:selected</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">selected选择框 选中</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">th:selected="(${xxx.id} == ${configObj.dd})"</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:src</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">图片类地址引入</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;img class="img-responsive" alt="App Logo" th:src="@{/img/logo.png}" /&gt;&nbsp;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:inline</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">定义js脚本可以使用变量</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;script type="text/javascript" th:inline="javascript"&gt;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:action</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">表单提交的地址</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;form action="subscribe.html" th:action="@{/subscribe}"&gt;</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;background-color:rgb(246,248,250);border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:remove</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">删除某个属性</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);"><code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">&lt;tr th:remove="all"&gt; 1.all:删除包含标签和所有的孩子。2.body:不包含标记删除,但删除其所有的孩子。3.tag:包含标记的删除,但不删除它的孩子。4.all-but-first:删除所有包含标签的孩子,除了第一个。5.none:什么也不做。这个值是有用的动态评估。</code></td> 
  </tr> 
  <tr style="margin:0px;padding:0px;border-top-color:rgb(198,203,209);"> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">th:attr</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">设置标签属性，多个属性可以用逗号分隔</td> 
   <td style="margin:0px;padding:6px 13px;font-family:'Microsoft YaHei', 'Helvetica Neue', Helvetica, 'Segoe UI', Arial, freesans, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';border-color:rgb(223,226,229);">比如&nbsp;<code style="margin:0px;padding:.2em 0px;font-family:'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;font-size:13.6px;background-color:rgba(27,31,35,.05);">th:attr="src=@{/image/aa.jpg},title=#{logo}"</code>，此标签不太优雅，一般用的比较少。</td> 
  </tr> 
 </tbody> 
</table>

还有非常多的标签，这里只列出最常用的几个,由于一个标签内可以包含多个th:x属性，其生效的优先级顺序为:`include,each,if/unless/switch/case,with,attr/attrprepend/attrappend,value/href,src ,etc,text/utext,fragment,remove。 `

## 几种常用的使用方法 ##

### 1、赋值、字符串拼接 ###

<p  th:text="${collect.description}">description</p>
     <span th:text="'Welcome to our application, ' + ${user.name} + '!'">

字符串拼接还有另外一种简洁的写法

### 2、条件判断 If/Unless ###

Thymeleaf中使用th:if和th:unless属性进行条件判断，下面的例子中，`<a>`标签只有在`th:if`中条件成立时才显示：

<a th:if="${myself=='yes'}" > </i> </a>
    <a th:unless=${session.user != null} th:href="@{/login}" >Login</a>

th:unless于th:if恰好相反，只有表达式中的条件不成立，才会显示其内容。

也可以使用 `(if) ? (then) : (else)` 这种语法来判断显示的内容

### 3、for 循环 ###

<tr  th:each="collect,iterStat : ${collects}"> 
         <th scope="row" th:text="${collect.id}">1</th>
         <td >
            <img th:src="${collect.webLogo}"/>
         </td>
         <td th:text="${collect.url}">Mark</td>
         <td th:text="${collect.title}">Otto</td>
         <td th:text="${collect.description}">@mdo</td>
         <td th:text="${terStat.index}">index</td>
     </tr>

iterStat称作状态变量，属性有：

*  index:当前迭代对象的index（从0开始计算）
 *  count: 当前迭代对象的index(从1开始计算)
 *  size:被迭代对象的大小
 *  current:当前迭代变量
 *  even/odd:布尔值，当前循环是否是偶数/奇数（从0开始计算）
 *  first:布尔值，当前循环是否是第一个
 *  last:布尔值，当前循环是否是最后一个

### 4、URL ###

URL在Web应用模板中占据着十分重要的地位，需要特别注意的是Thymeleaf对于URL的处理是通过语法@\{…\}来处理的。 如果需要Thymeleaf对URL进行渲染，那么务必使用th:href，th:src等属性，下面是一个例子

<a  th:href="@{/standard/{type}(type=${type})}">view</a>
    
    
    <a href="details.html" th:href="@{/order/{orderId}/details(orderId=${o.id})}">view</a>

设置背景

根据属性值改变背景

几点说明：

*  上例中URL最后的`(orderId=${o.id})` 表示将括号内的内容作为URL参数处理，该语法避免使用字符串拼接，大大提高了可读性
 *  `@{...}`表达式中可以通过`{orderId}`访问Context中的orderId变量
 *  `@{/order}`是Context相关的相对路径，在渲染时会自动添加上当前Web应用的Context名字，假设context名字为app，那么结果应该是/app/order

### 5、内联js ###

内联文本：\[\[…\]\]内联文本的表示方式，使用时，必须先用th:inline=”text/javascript/none”激活，th:inline可以在父级标签内使用，甚至作为body的标签。内联文本尽管比th:text的代码少，不利于原型显示。

js附加代码：

/*[+
    var msg = 'This is a working application';
    +]*/

js移除代码：

/*[- */
    var msg = 'This is a non-working template';
    /* -]*/

### 6、内嵌变量 ###

为了模板更加易用，Thymeleaf还提供了一系列Utility对象（内置于Context中），可以通过\#直接访问：

*  dates ： java.util.Date的功能方法类。
 *  calendars : 类似\#dates，面向java.util.Calendar
 *  numbers : 格式化数字的功能方法类
 *  strings : 字符串对象的功能类，contains,startWiths,prepending/appending等等。
 *  objects: 对objects的功能类操作。
 *  bools: 对布尔值求值的功能方法。
 *  arrays：对数组的功能类方法。
 *  lists: 对lists功能类方法
 *  sets
 *  maps  
    …

下面用一段代码来举例一些常用的方法：

#### dates ####

/*
     * Format date with the specified pattern
     * Also works with arrays, lists or sets
     */
    ${#dates.format(date, 'dd/MMM/yyyy HH:mm')}
    ${#dates.arrayFormat(datesArray, 'dd/MMM/yyyy HH:mm')}
    ${#dates.listFormat(datesList, 'dd/MMM/yyyy HH:mm')}
    ${#dates.setFormat(datesSet, 'dd/MMM/yyyy HH:mm')}
    
    /*
     * Create a date (java.util.Date) object for the current date and time
     */
    ${#dates.createNow()}
    
    /*
     * Create a date (java.util.Date) object for the current date (time set to 00:00)
     */
    ${#dates.createToday()}

#### strings ####

/*
     * Check whether a String is empty (or null). Performs a trim() operation before check
     * Also works with arrays, lists or sets
     */
    ${#strings.isEmpty(name)}
    ${#strings.arrayIsEmpty(nameArr)}
    ${#strings.listIsEmpty(nameList)}
    ${#strings.setIsEmpty(nameSet)}
    
    /*
     * Check whether a String starts or ends with a fragment
     * Also works with arrays, lists or sets
     */
    ${#strings.startsWith(name,'Don')}                  // also array*, list* and set*
    ${#strings.endsWith(name,endingFragment)}           // also array*, list* and set*
    
    /*
     * Compute length
     * Also works with arrays, lists or sets
     */
    ${#strings.length(str)}
    
    /*
     * Null-safe comparison and concatenation
     */
    ${#strings.equals(str)}
    ${#strings.equalsIgnoreCase(str)}
    ${#strings.concat(str)}
    ${#strings.concatReplaceNulls(str)}
    
    /*
     * Random
     */
    ${#strings.randomAlphanumeric(count)}

## 使用thymeleaf布局 ##

使用thymeleaf布局非常的方便

定义代码片段

在页面任何地方引入：

th:include 和 th:replace区别，include只是加载，replace是替换

返回的HTML如下：

下面是一个常用的后台页面布局，将整个页面分为头部，尾部、菜单栏、隐藏栏，点击菜单只改变content区域的页面

<body class="layout-fixed">
      <div th:fragment="navbar"  class="wrapper"  role="navigation">
    	<div th:replace="fragments/header :: header">Header</div>
    	<div th:replace="fragments/left :: left">left</div>
    	<div th:replace="fragments/sidebar :: sidebar">sidebar</div>
    	<div layout:fragment="content" id="content" ></div>
    	<div th:replace="fragments/footer :: footer">footer</div>
      </div>
    </body>

任何页面想使用这样的布局值只需要替换中见的 content模块即可

<html xmlns:th="http://www.thymeleaf.org" layout:decorator="layout">
       <body>
          <section layout:fragment="content">
        ...

也可以在引用模版的时候传参

layout 是文件地址，如果有文件夹可以这样写 fileName/layout:htmlhead  
htmlhead 是指定义的代码片段 如 `th:fragment="copy"`

## 源码案例 ##

这里有一个开源项目几乎使用了这里介绍的所有标签和布局，大家可以参考：

[示例代码-github][-github]

[示例代码-码云][-]

## 参考 ##

[thymeleaf官方指南][thymeleaf]  
[新一代Java模板引擎Thymeleaf][Java_Thymeleaf]  
[Thymeleaf基本知识][Thymeleaf]   
[thymeleaf总结文章][thymeleaf 1]  
[Thymeleaf 模板的使用][Thymeleaf 1]  
[thymeleaf 学习笔记][thymeleaf 2]

[-github]: https://github.com/cloudfavorites/favorites-web
[-]: https://gitee.com/ityouknow/favorites-web
[thymeleaf]: http://www.thymeleaf.org/doc/tutorials/2.1/thymeleafspring.html#integrating-thymeleaf-with-spring
[Java_Thymeleaf]: http://www.tianmaying.com/tutorial/using-thymeleaf
[Thymeleaf]: http://www.webinno.cn/blog/article/view/131
[thymeleaf 1]: http://v8en.com/news/list/47/0
[Thymeleaf 1]: http://www.cnblogs.com/lazio10000/p/5603955.html
[thymeleaf 2]: http://www.blogjava.net/bjwulin/archive/2013/02/07/395234.html