SpringBoot学习笔记-Web开发

SpringBoot学习笔记-Web开发

SpringBoot学习笔记-Web开发

1 SpringBoot与Web开发

1.1 SpringBoot对静态资源的映射规则

  • 引入前端框架资源, 所有 /webjars/** ,都去 classpath:/META-INF/resources/webjars 找资源
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
    if (!this.resourceProperties.isAddMappings()) {
        logger.debug("Default resource handling disabled");
        return;
    }
    Duration cachePeriod = this.resourceProperties.getCache().getPeriod();
    CacheControl cacheControl = this.resourceProperties.getCache()
        .getCachecontrol().toHttpCacheControl();
    if (!registry.hasMappingForPattern("/webjars/**")) {
        customizeResourceHandlerRegistration(registry
              .addResourceHandler("/webjars/**")
              .addResourceLocations("classpath:/META-INF/resources/webjars/")
              .setCachePeriod(getSeconds(cachePeriod))
              .setCacheControl(cacheControl));
    }
    String staticPathPattern = this.mvcProperties.getStaticPathPattern();
    if (!registry.hasMappingForPattern(staticPathPattern)) {
        customizeResourceHandlerRegistration(
              registry.addResourceHandler(staticPathPattern)
                  .addResourceLocations(getResourceLocations(
                      this.resourceProperties.getStaticLocations()))
                  .setCachePeriod(getSeconds(cachePeriod))
                  .setCacheControl(cacheControl));
    }
}
  • 引入自己的前端页面资源, SpringBoot提供一下静态资源存放的文件夹
    • classpath: /META-INF/resources/
    • classpath: /resources/
    • classpath: /static/
    • classpath: /public/
    • / : 当前页面的根路径
  • 配置静态资源路径
spring:
  resources:
    static-locations: classpath:/hello, classpath:/test/

1.2 模板引擎

  • 常用的模板引擎
    • JSP
    • Velocity
    • Freemarker
    • Thymeleaf
  • 模板引擎的原理

template-engine.png

  • SpringBoot推荐使用 Thymeleaf 模板引擎

1.2.1 引入Thymeleaf

<!-- 引入Thymeleaf模板引擎 -->
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
  • 切换为 Thymeleaf3 版本
<!-- 布局功能的支持程序 thymeleaf3主程序 layout2以上版本 -->
<properties>
  <thymeleaf.version>3.0.2.RELEASE</thymeleaf.version>
  <thymeleaf-layout-dialect.veresion>2.1.1</thymeleaf-layout-dialect.veresion>
</properties>

1.2.2 Thymeleaf使用

  • 导入thymeleaf的名称空间
<html xmlns:th="http://www.thymeleaf.org">
  • 使用案例
// 查出一些数据,在页面展示
@RequestMapping("/success")
public String success(Map<String, Object> map) {
    map.put("hello", "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>成功!</h1>
<!-- th:text 将div里面的文本内容设置为指定的值-->
<div th:text="${hello}">这是显示欢迎信息</div>
</body>
</html>

1.2.3 Thymeleaf语法规则

  • th:text: 改变当前元素的文本内容.
  • th:任意html属性: 来替换原生html属性的值.

thymeleaf.png

  • 标准表达式语法
Simple expressions:（表达式语法）
    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).

    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>

    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:

Date: 2018-11-25 08:10

Author: devinkin

Created: 2018-11-25 日 13:32

Validate

posted @ 2018-11-25 13:33  EmacsDevinkin  阅读(184)  评论(0)    收藏  举报