Spring Boot学习笔记-4
Spring Boot学习笔记-4
一、Web开发
1.创建Spring Boot应用，选择相应模块
2.在配置文件指定相应配置(其它由SpringBoot自动配置)
3.编写业务代码
（1）静态资源映射
1.所有/webjars/，都去classpath:/META-INF/resources/webjars/下找相关资源
webjars:以jar包形式引入静态资源 (https://www.webjars.com/)
//WebMvcAutoConfiguration
if (!registry.hasMappingForPattern("/webjars/**")) {
customizeResourceHandlerRegistration(registry.addResourceHandler("/webjars/**")
.addResourceLocations("classpath:/META-INF/resources/webjars/")
.setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl));
}
http://localhost:8080/webjars/jquery/3.5.1/jquery.js
2.无处理自动从下列文件夹查找静态资源
例如localhost:8080/abc若abc无处理则去下列目录查找
- “classpath:/META-INF/resources/”
- “classpath:/resources/”
- “classpath:/static/”
- “classpath:/public/”
- “/” 当前项目根路径
3.欢迎页(localhost:8080)从静态资源文件夹(见2)中查找index.html文件
//welcomePageHandlerMapping().getWelcomePage().getIndexHtml()
private Resource getIndexHtml(String location) {
return this.resourceLoader.getResource(location + "index.html");
}
<html lang="en">
<head>
<meta charset="UTF-8">
<title>首页title>
head>
<body>
首页
body>
html>
以上为Spring Boot默认静态资源查询地址，可以在配置文件中修改：
spring.resources.static-locations=XXX
（2）模板引擎
将模板中动态值的表达式与数据结合输出
JSP,Velocity,Freemarker,Thymeleaf
Spring Boot推荐使用Thymeleaf
1.配置依赖+版本
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-thymeleafartifactId>
dependency>
//layout2以上版本才支持thymeleaf3
<properties>
<thymeleaf-layout-dialect.version>2.2.2thymeleaf-layout-dialect.version>
properties>
2.取值
@EnableConfigurationProperties(ThymeleafProperties.class)
//ThymeleafProperties
@ConfigurationProperties(prefix = "spring.thymeleaf")
public class ThymeleafProperties {
private static final Charset DEFAULT_ENCODING = StandardCharsets.UTF_8;
public static final String DEFAULT_PREFIX = "classpath:/templates/";
public static final String DEFAULT_SUFFIX = ".html";
//将html文件放在classpath:/templates/下即可自动渲染
//导入thymeleaf名称空间(开启语法提示)
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Titletitle>
head>
<body>
<h1>成功~h1>
<div id="div01" class="myDiv" th:id="${Hello}" th:class="${Hello}" th:text="${Hello}">欢迎信息div>
body>
html>
@RequestMapping("/success")
public String success(Map<String,Object> map)
{
map.put("Hello","你好");
return "success";
}
静态页面
服务器启动：
3.语法规则
1）取值
//在div模块中
//用XXX替换该属性的原生值(一般是用"${XXX}"取值)
div>
1.片段包含
2.遍历
3.条件判断
4.变量声明
5.任意属性修改(支持前后添加)
6.修改指定属性默认值
7.修改标签体内容(text转义特殊字符，utext不转义)
8.声明片段
2）表达式
Simple expressions:
//OGNL，获取变量值
Variable Expressions: ${...}
1.获取对象属性
${person.father.name}
${person['father']['name']}
${countriesByCode.ES}
${personsByName['Stephen Zucchini'].age}
${personsArray[0].name}
2.调用方法
${person.createCompleteName()}
${person.createCompleteNameWithSeparator('-')}
3.使用内置基本对象
#ctx : the context object.
#vars: the context variables.
#locale : the context locale.
#request : (only in Web Contexts) the HttpServletRequest object.
#response : (only in Web Contexts) the HttpServletResponse object.
#session : (only in Web Contexts) the HttpSession object.
#servletContext : (only in Web Contexts) the ServletContext object.
//使用方式见附录
4.使用内置工具对象
#execInfo : information about the template being processed.
#messages : methods for obtaining externalized messages inside variables expressions, in the same way as they would be obtained using #{…} syntax.
#uris : methods for escaping parts of URLs/URIs
#conversions : methods for executing the configured conversion service (if any).
#dates : methods for java.util.Date objects: formatting, component extraction, etc.
#calendars : analogous to #dates , but for java.util.Calendar objects.
#numbers : methods for formatting numeric objects.
#strings : methods for String objects: contains, startsWith, prepending/appending, etc.
#objects : methods for objects in general.
#bools : methods for boolean evaluation.
#arrays : methods for arrays.
#lists : methods for lists.
#sets : methods for sets.
#maps : methods for maps.
#aggregates : methods for creating aggregates on arrays or collections.
#ids : methods for dealing with id attributes that might be repeated (for example, as a result of an iteration)
//使用方式见附录
//选择表达式
Selection Variable Expressions: *{...}
//以下两种写法含义相同(与${}的不同)：
Name: Sebastian.
Name: Sebastian.
//获取国际化内容
Message Expressions: #{...}
//定义URL
Link URL Expressions: @{...}
//片段引用表达式
Fragment Expressions: ~{...}
//字面量
Literals:
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 ,…
//文本操作
Text operations:
String concatenation: +
Literal substitutions: |The name is ${name}|
//数学运算
Arithmetic operations:
Binary operators: + , - , * , / , %
Minus sign (unary operator): -
//布尔运算
Boolean operations:
Binary operators: and , or
Boolean negation (unary operator): ! , not
//比较运算
Comparisons and equality:
Comparators: > , < , >= , <= ( gt , lt , ge , le )
Equality operators: == , != ( eq , ne )
//条件运算
Conditional operators:
If-then: (if) ? (then)
If-then-else: (if) ? (then) : (else)
Default: (value) ?: (defaultvalue)
//特殊操作
Special tokens:
No-Operation: _
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Titletitle>
head>
<body>
<h1>成功~h1>
<div th:text="${Hello}">div>
<div th:utext="${Hello}">div>
<hr/>
<h4 th:text="${user}" th:each="user:${users}">h4>
<hr/>
<h4>
<span th:text="${user}" th:each="user:${users}">span>
h4>
body>
html>
