[SpringBoot之一入门] 05-静态资源及模板引擎Thymeleaf

概要

1.静态资源的映射规则
2.Thymeleaf语法及使用

一、静态资源的映射规则

1.自动配置

xxxxAutoConfiguration:帮我们给容器中自动配置组件;
xxxxProperties:配置类来封装配置文件的内容;

web开发资源相关的配置类

@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
public class ResourceProperties implements ResourceLoaderAware {
  //可以设置和静态资源有关的参数,缓存时间等
@Configuration
@ConditionalOnWebApplication
@ConditionalOnClass({Servlet.class, DispatcherServlet.class, WebMvcConfigurerAdapter.class})
@ConditionalOnMissingBean({WebMvcConfigurationSupport.class})
@AutoConfigureOrder(-2147483638)
@AutoConfigureAfter({DispatcherServletAutoConfiguration.class, ValidationAutoConfiguration.class})
public class WebMvcAutoConfiguration {
    //部分方法及类解释
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        if (!this.resourceProperties.isAddMappings()) {
            logger.debug("Default resource handling disabled");
            return;
        }
        Integer cachePeriod = this.resourceProperties.getCachePeriod();
        if (!registry.hasMappingForPattern("/webjars/**")) {
            customizeResourceHandlerRegistration(
                    registry.addResourceHandler("/webjars/**")
                            .addResourceLocations(
                                    "classpath:/META-INF/resources/webjars/")
                    .setCachePeriod(cachePeriod));
        }
        String staticPathPattern = this.mvcProperties.getStaticPathPattern();
         //静态资源文件夹映射
        if (!registry.hasMappingForPattern(staticPathPattern)) {
            customizeResourceHandlerRegistration(
                    registry.addResourceHandler(staticPathPattern)
                            .addResourceLocations(
                                    this.resourceProperties.getStaticLocations())
                    .setCachePeriod(cachePeriod));
        }
    }

    //配置欢迎页映射
    @Bean
    public WelcomePageHandlerMapping welcomePageHandlerMapping(
            ResourceProperties resourceProperties) {
        return new WelcomePageHandlerMapping(resourceProperties.getWelcomePage(),
                this.mvcProperties.getStaticPathPattern());
    }

    //配置喜欢的图标
    @Configuration
    @ConditionalOnProperty(value = "spring.mvc.favicon.enabled", matchIfMissing = true)
    public static class FaviconConfiguration {

        private final ResourceProperties resourceProperties;

        public FaviconConfiguration(ResourceProperties resourceProperties) {
            this.resourceProperties = resourceProperties;
        }

        @Bean
        public SimpleUrlHandlerMapping faviconHandlerMapping() {
            SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();
            mapping.setOrder(Ordered.HIGHEST_PRECEDENCE + 1);
            //所有  **/favicon.ico 
            mapping.setUrlMap(Collections.singletonMap("**/favicon.ico",
                    faviconRequestHandler()));
            return mapping;
        }

        @Bean
        public ResourceHttpRequestHandler faviconRequestHandler() {
            ResourceHttpRequestHandler requestHandler = new ResourceHttpRequestHandler();
            requestHandler
                    .setLocations(this.resourceProperties.getFaviconLocations());
            return requestHandler;
        }
    }
}

2.静态资源文件

1)、所有 /webjars/** ,都去 classpath:/META-INF/resources/webjars/ 找资源;

webjars:以jar包的方式引入静态资源; http://www.webjars.org/
访问上面地址,找到jquery需要引入的pom文件

<!--引入jquery-webjar在访问的时候只需要写webjars下面资源的名称即可-->
<dependency>
    <groupId>org.webjars</groupId>
    <artifactId>jquery</artifactId>
    <version>3.3.1</version>
</dependency>
localhost:8080/webjars/jquery/3.3.1/jquery.js

2)、”/**” 访问当前项目的任何资源,都去(静态资源的文件夹)找映射

"classpath:/META-INF/resources/", 
"classpath:/resources/",
"classpath:/static/", 
"classpath:/public/" 
"/":当前项目的根路径
localhost:8080/abc -->  去静态资源文件夹里面找abc

3)、欢迎页; 静态资源文件夹下的所有index.html页面;被”/**”映射;

localhost:8080/   --> index页面

4)、所有的 **/favicon.ico 都是在静态资源文件下找;
启动项目后,浏览器上方会使用该图标

二、Thymeleaf模板引擎语法及使用

模板引擎有:JSP、Velocity、Freemarker、Thymeleaf;
SpringBoot推荐的Thymeleaf;语法更简单,功能更强大;

1、引入thymeleaf;

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

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
    <!-- Springboot本身管理的版本太低,可以自行更改版本号 -->
</dependency>

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:

2.1 导入thymeleaf的名称空间

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

2.2 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}"></div>
</body>
</html>

2.3 语法规则

这里写图片描述

2.4 表达式

Simple expressions:(表达式语法)
    一、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.
               //如:
               ${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).

    二、Selection Variable Expressions: *{...}  //选择表达式:和${}在功能上是一样;
        补充:配合 th:object="${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>

    三、Message Expressions: #{...}  //获取国际化内容

    四、Link URL Expressions: @{...} //定义URL;
            @{/order/process(execId=${execId},execType='FAST')}

    五、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: _ 

三、Thymeleaf进阶使用(以后有空再深入)

未完待续…

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转载自blog.csdn.net/Justszh/article/details/82527840