• SpringBoot-web模板引擎Thymeleaf(七)


    JSP、Velocity、Freemarker、Thymeleaf都是模板引擎.

    把模板和数据放到模板引擎中,然后解析输出.

    SpringBoot推荐使用Thymeleaf;

    Thymeleaf语法更简单,功能更强大.

    1、引入Thymeleaf

    maven依赖:

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

    我们也可以自己到SpringBoot的官网找自己想要的版本.

    但是要注意切换thymeleaf版本需要到maven的配置文件properties中设置,关于thymeleaf的版本一般都放在了github上搜索即可看到.

    如果我们的thymeleaf是3版本以上的 layout2以上版本 .

    <properties>
            <thymeleaf.version>3.0.9.RELEASE</thymeleaf.version>    
            <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";

    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.

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

    2、使用thymeleaf语法;

    controller中携带一个参数,在html中获取

    @RequestMapping("/success")
        public String success(Model model){
      model.addAttribute("msg","你好");
        return "success";
        }
    <!DOCTYPE html>
    <html lang="en" xmlns:th="http://www.thymeleaf.org">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
    <h1>你好啊</h1>
    <div th:text="${msg}"></div>
    </body>
    </html>

    访问:localhost:8080/success    就可以获取到''你好''这个值了.

    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

    (2)表达式(Simple expressions)

    Variable Expressions: ${...}:获取变量值.

    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).

    Selection Variable Expressions: *{...}

    选择表达式:和${}在功能上是一样

    他可以配合配合 th:object来用

    th:object="${session.user}:
       <div th:object="${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>

     Message Expressions: #{...}

    获取国际化内容

    Link URL Expressions: @{...}

    定义URL

     @{/order/process(execId=${execId},execType='FAST')}

     Fragment Expressions: ~{...}

    片段引用表达式

    <div th:insert="~{commons :: main}">...</div>
                
    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 ,…
    Text operations:(文本操作)
        String concatenation: +
        Literal substitutions: |The name is ${name}|
    Arithmetic operations:(数学运算)
        Binary operators: + , - , * , / , %
        Minus sign (unary operator): -
    Boolean operations:(布尔运算)
        Binary operators: and , or
        Boolean negation (unary operator): ! , not
    Comparisons and equality:(比较运算)
        Comparators: > , < , >= , <= ( gt , lt , ge , le )
        Equality operators: == , != ( eq , ne )
    Conditional operators:条件运算(三元运算符)
        If-then: (if) ? (then)
        If-then-else: (if) ? (then) : (else)
        Default: (value) ?: (defaultvalue)
    Special tokens:
        No-Operation: _ 
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  • 原文地址:https://www.cnblogs.com/xiaoqiqistudy/p/11349010.html
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