4.3 thymeleaf模板引擎的使用

时间:2022-11-17 18:22:24

 参考说明:以下笔记参考来自尚硅谷springboot教学中的笔记!

 

thymeleaf官网docs: https://www.thymeleaf.org/documentation.html

模板引擎:

  JSP、Velocity、Freemarker、Thymeleaf

4.3 thymeleaf模板引擎的使用

SpringBoot推荐的Thymeleaf;

语法更简单,功能更强大;

 

1、引入thymeleaf:

<dependency>
       <groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId> 2.1.6 </dependency>

切换thymeleaf版本 <properties> <thymeleaf.version>3.0.9.RELEASE</thymeleaf.version> <!-- 布局功能的支持程序 thymeleaf3主程序 layout2以上版本 --> <!-- thymeleaf2 layout1--> <thymeleaf-layout-dialect.version>2.2.2</thymeleaf-layout-dialect.version> </properties>

2、Thymeleaf使用

@ConfigurationProperties(prefix = "spring.thymeleaf")
public class ThymeleafProperties {

    private static final Charset DEFAULT_ENCODING = Charset.forName("UTF-8");

    private static final MimeType DEFAULT_CONTENT_TYPE = MimeType.valueOf("text/html");

    public static final String DEFAULT_PREFIX = "classpath:/templates/";

    public static final String DEFAULT_SUFFIX = ".html";
      //

以上是package org.springframework.boot.autoconfigure.thymeleaf;包中的源码,放在这里主要是告诉你模块该如何配置;

只要我们把HTML页面放在classpath:/templates/,thymeleaf就能自动渲染;

使用:

(1) 导入thymeleaf的名称空间(导入后有语法提示)

<html lang="en" xmlns:th="http://www.thymeleaf.org">

(2) 使用thymeleaf语法:

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>成功!</h1>
    <!--th:text 将div里面的文本内容设置为 -->
    <div th:text="${hello}">这是显示欢迎信息</div>
</body>
</html>

3、语法规则

1)、th:text;改变当前元素里面的文本内容;

​ th:任意html属性;来替换原生属性的值(eg: th:id=1改变id的值, th:class=“c1”改变class的值)

4.3 thymeleaf模板引擎的使用

 

补充:

<div th:remove="tag">
<div>唐嫣</div> //包含标记的标签将被删除,即这里的外层div将被删除 参考:th:remove用法
</div>

 

2)、表达式?

1、Simple expressions:(表达式语法) (1)Variable Expressions: ${...}:获取变量值;OGNL; 1)、获取对象的属性、调用方法 2)、使用内置的基本对象:
                #ctx : the context object.
                #vars: the context variables.
                #locale : the context locale.
                #request : (only in Web Contexts) the HttpServletRequest object.
                #response : (only in Web Contexts) the HttpServletResponse object.
                #session : (only in Web Contexts) the HttpSession object.
                #servletContext : (only in Web Contexts) the ServletContext object.
                
                ${session.foo}
            3)、内置的一些工具对象:
                #execInfo : information about the template being processed.
                #messages : methods for obtaining externalized messages inside variables expressions, in the same way as they would be obtained using #{…} syntax.
                #uris : methods for escaping parts of URLs/URIs
                #conversions : methods for executing the configured conversion service (if any).
                #dates : methods for java.util.Date objects: formatting, component extraction, etc.
                #calendars : analogous to #dates , but for java.util.Calendar objects.
                #numbers : methods for formatting numeric objects.
                #strings : methods for String objects: contains, startsWith, prepending/appending, etc.
                #objects : methods for objects in general.
                #bools : methods for boolean evaluation.
                #arrays : methods for arrays.
                #lists : methods for lists.
                #sets : methods for sets.
                #maps : methods for maps.
                #aggregates : methods for creating aggregates on arrays or collections.
                #ids : methods for dealing with id attributes that might be repeated (for example, as a result of an iteration).

    (2)Selection Variable Expressions: *{...}:选择表达式:和${}在功能上是一样; 补充:配合 th:object="${session.user}:#只有作为全局变量使用的时候才是不一样的
       eg:  用th:object从session里面取出user对象(即将取出来的对象赋值给Object),以后要用user对象的值,就可以在当前的div里面,
       "*"号就代表刚才的th:object对象,然后直接获取对象的属性即可。
    <div th:object="${session.user}"> <p>Name: <span th:text="*{firstName}">Sebastian</span>.</p> <p>Surname: <span th:text="*{lastName}">Pepper</span>.</p> <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p> </div>
    --以上方式等于如下方式$和*号功能是一样的,而且$和*可以混合使用
    <div th:object="${session.user}">
      <p>Name: <span th:text="*{firstName}">Sebastian</span>.</p>
      <p>Surname: <span th:text="${session.user.lastName}">Pepper</span>.</p>
      <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p>
    </div>
(3)Message Expressions: #{...}:获取国际化内容 (4)Link URL Expressions: @{...}:定义URL; @{/order/process(execId=${execId},execType='FAST')} (5)Fragment Expressions: ~{...}:片段引用表达式 <div th:insert="~{commons :: main}">...</div> 2、Literals(字面量) Text literals: 'one text' , 'Another one!' ,… Number literals: 0 , 34 , 3.0 , 12.3 ,… Boolean literals: true , false Null literal: null Literal tokens: one , sometext , main ,… 3、Text operations:(文本操作) String concatenation: + Literal substitutions: |The name is ${name}| 4、Arithmetic operations:(数学运算) Binary operators: + , - , * , / , % Minus sign (unary operator): - 5、Boolean operations:(布尔运算) Binary operators: and , or Boolean negation (unary operator): ! , not 6、Comparisons and equality:(比较运算) Comparators: > , < , >= , <= ( gt , lt , ge , le ) Equality operators: == , != ( eq , ne ) 7、Conditional operators:条件运算(三元运算符) If-then: (if) ? (then) If-then-else: (if) ? (then) : (else) Default: (value) ?: (defaultvalue) 8、Special tokens(特殊操作): No-Operation: _