SpringBootWeb开发-4

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上一级页面：ssm-spring-boot速成学习索引

前言

43、视图解析-Thymeleaf初体验

Thymeleaf is a modern server-side Java template engine for both web and standalone environments.

Thymeleaf’s main goal is to bring elegant natural templates to your development workflow — HTML that can be correctly displayed in browsers and also work as static prototypes, allowing for stronger collaboration in development teams.

With modules for Spring Framework, a host of integrations with your favourite tools, and the ability to plug in your own functionality, Thymeleaf is ideal for modern-day HTML5 JVM web development — although there is much more it can do.——Link

Thymeleaf官方文档

thymeleaf使用

引入Starter

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

自动配置好了thymeleaf

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@Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties(ThymeleafProperties.class)
@ConditionalOnClass({ TemplateMode.class, SpringTemplateEngine.class })
@AutoConfigureAfter({ WebMvcAutoConfiguration.class, WebFluxAutoConfiguration.class })
public class ThymeleafAutoConfiguration {
    ...
}

自动配好的策略

  1. 所有thymeleaf的配置值都在 ThymeleafProperties

  2. 配置好了 SpringTemplateEngine

  3. 配好了 ThymeleafViewResolver

  4. 我们只需要直接开发页面

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public static final String DEFAULT_PREFIX = "classpath:/templates/";//模板放置处
public static final String DEFAULT_SUFFIX = ".html";//文件的后缀名

编写一个控制层：

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@Controller
public class ViewTestController {
    @GetMapping("/hello")
    public String hello(Model model){
        //model中的数据会被放在请求域中 request.setAttribute("a",aa)
        model.addAttribute("msg","一定要大力发展工业文化");
        model.addAttribute("link","http://www.baidu.com");
        return "success";
    }
}

/templates/success.html：

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<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1 th:text="${msg}">nice</h1>
<h2>
    <a href="www.baidu.com" th:href="${link}">去百度</a>  <br/>
    <a href="www.google.com" th:href="@{/link}">去百度</a>
</h2>
</body>
</html>
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server:
  servlet:
    context-path: /app #设置应用名

这个设置后，URL要插入/app, 如http://localhost:8080/app/hello.html。

基本语法

表达式

表达式名字 语法 用途
变量取值 ${…} 获取请求域、session域、对象等值
选择变量 *{…} 获取上下文对象值
消息 #{…} 获取国际化等值
链接 @{…} 生成链接
片段表达式 ~{…} jsp:include 作用，引入公共页面片段

字面量

  • 文本值: ‘one text’ , ‘Another one!’ ,…
  • 数字: 0 , 34 , 3.0 , 12.3 ,…
  • 布尔值: true , false
  • 空值: null
  • 变量： one，two，…. 变量不能有空格

文本操作

  • 字符串拼接: +
  • 变量替换: |The name is ${name}|

数学运算

  • 运算符: + , - , * , / , %

布尔运算

  • 运算符: and , or
  • 一元运算: ! , not

比较运算

  • 比较: > , < , >= , <= ( gt , lt , ge , le )
  • 等式: == , != ( eq , ne )

条件运算

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

特殊操作

  • 无操作： _

设置属性值-th:attr

  • 设置单个值
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<form action="subscribe.html" th:attr="action=@{/subscribe}">
  <fieldset>
    <input type="text" name="email" />
    <input type="submit" value="Subscribe!" th:attr="value=#{subscribe.submit}"/>
  </fieldset>
</form>
  • 设置多个值
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<img src="../../images/gtvglogo.png"  
     th:attr="src=@{/images/gtvglogo.png},title=#{logo},alt=#{logo}" />

官方文档 - 5 Setting Attribute Values

迭代

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<tr th:each="prod : ${prods}">
    <td th:text="${prod.name}">Onions</td>
    <td th:text="${prod.price}">2.41</td>
    <td th:text="${prod.inStock}? #{true} : #{false}">yes</td>
</tr>
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<tr th:each="prod,iterStat : ${prods}" th:class="${iterStat.odd}? 'odd'">
    <td th:text="${prod.name}">Onions</td>
    <td th:text="${prod.price}">2.41</td>
    <td th:text="${prod.inStock}? #{true} : #{false}">yes</td>
</tr>

条件运算

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<a href="comments.html"
	th:href="@{/product/comments(prodId=${prod.id})}"
	th:if="${not #lists.isEmpty(prod.comments)}">view</a>
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<div th:switch="${user.role}">
      <p th:case="'admin'">User is an administrator</p>
      <p th:case="#{roles.manager}">User is a manager</p>
      <p th:case="*">User is some other thing</p>
</div>

属性优先级

Order Feature Attributes
1 Fragment inclusion th:insert th:replace
2 Fragment iteration th:each
3 Conditional evaluation th:if th:unless th:switch th:case
4 Local variable definition th:object th:with
5 General attribute modification th:attr th:attrprepend th:attrappend
6 Specific attribute modification th:value th:href th:src …
7 Text (tag body modification) th:text th:utext
8 Fragment specification th:fragment
9 Fragment removal th:remove

官方文档 - 10 Attribute Precedence

SpringBootWeb开发-5

spring-boot-web-开发-5

参考、引用、致谢