1、簡介
使用SpringBoot；
1）、創建SpringBoot應用，選中我們需要的模塊；
2）、SpringBoot已經默認將這些場景配置好了，只需要在配置文件中指定少量配置就可以運行起來
3）、自己編寫業務代碼；
自動配置原理？
這個場景SpringBoot幫我們配置了什麼？能不能修改？能修改哪些配置？能不能擴展？xxx
xxxxAutoConfiguration：幫我們給容器中自動配置組件；
xxxxProperties:配置類來封裝配置文件的內容；
2、SpringBoot對靜態資源的映射規則；
@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
public class ResourceProperties implements ResourceLoaderAware {
//可以設置和靜態資源有關的參數，緩存時間等
WebMvcAuotConfiguration：
@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();
//靜態資源文件夾映射
if (!registry.hasMappingForPattern(staticPathPattern)) {
customizeResourceHandlerRegistration(
registry.addResourceHandler(staticPathPattern)
.addResourceLocations(
this.resourceProperties.getStaticLocations())
.setCachePeriod(cachePeriod));
}
}
//配置歡迎頁映射
@Bean
public WelcomePageHandlerMapping welcomePageHandlerMapping(
ResourceProperties resourceProperties) {
return new WelcomePageHandlerMapping(resourceProperties.getWelcomePage(),
this.mvcProperties.getStaticPathPattern());
}
//配置喜歡的圖標
@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;
}
}
1）、所有 /webjars/** ，都去 classpath:/META-INF/resources/webjars/ 找資源；
webjars：以jar包的方式引入靜態資源；
http://www.webjars.org/
pom文件裏面引入：
<dependency>
<groupId>org.webjars</groupId>
<artifactId>jquery</artifactId>
<version>3.2.1</version>
</dependency>
2）、"/**" 訪問當前項目的任何資源，都去（靜態資源的文件夾）找映射
"classpath:/META-INF/resources/",
"classpath:/resources/",
"classpath:/static/",
"classpath:/public/"
"/"：當前項目的根路徑
localhost:8080/abc === 去靜態資源文件夾裏面找abc
3）、歡迎頁； 靜態資源文件夾下的所有index.html頁面；被"/**"映射；
localhost:8080/ 找index頁面
4）、所有的 **/favicon.ico 都是在靜態資源文件下找；
3、模板引擎
JSP、Velocity、Freemarker、Thymeleaf
SpringBoot推薦的Thymeleaf；
語法更簡單，功能更強大；
1、引入thymeleaf；
<!--引入thymeleaf模板引擎-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</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";
//
只要我們把HTML頁面放在classpath:/templates/，thymeleaf就能自動渲染；
例如我寫一個測試類：
/**
* 該處返回 "success"返回的是 resources/templates目錄下面的頁面
* 該出要返回的是頁面，所以不能配置@ResponseBody註解，如果配置了該註解會以字符串直接輸出"success"
* @return success.html
*/
@RequestMapping("/success")
public String success(){
return "success";
}
然後 resources/templates目錄下新建success.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>跳轉成功頁面</h1>
</body>
</html>
使用：
1、導入thymeleaf的名稱空間
<html lang="en" xmlns:th="http://www.thymeleaf.org">
2、使用thymeleaf語法；
後端代碼改寫成：
<!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 將div裏面的文本內容設置爲 -->
<div th:text="${hello}">這是顯示歡迎信息</div>
</body>
</html>
3、語法規則
1）、th:text；改變當前元素裏面的文本內容；
th：任意html屬性；來替換原生屬性的值
2）、表達式？
Simple expressions:（表達式語法）
Variable Expressions: ${...}：獲取變量值；OGNL；
1）、獲取對象的屬性、調用方法
2）、使用內置的基本對象：
#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.
${session.foo}
3）、內置的一些工具對象：
#execInfo : information about the template being processed.
#messages : methods for obtaining externalized messages inside variables expressions, in the same way as they would be obtained using #{…} syntax.
#uris : methods for escaping parts of URLs/URIs
#conversions : methods for executing the configured conversion service (if any).
#dates : methods for java.util.Date objects: formatting, component extraction, etc.
#calendars : analogous to #dates , but for java.util.Calendar objects.
#numbers : methods for formatting numeric objects.
#strings : methods for String objects: contains, startsWith, prepending/appending, etc.
#objects : methods for objects in general.
#bools : methods for boolean evaluation.
#arrays : methods for arrays.
#lists : methods for lists.
#sets : methods for sets.
#maps : methods for maps.
#aggregates : methods for creating aggregates on arrays or collections.
#ids : methods for dealing with id attributes that might be repeated (for example, as a result of an iteration).
Selection Variable Expressions: *{...}：選擇表達式：和${}在功能上是一樣；
補充：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: #{...}：獲取國際化內容
Link URL Expressions: @{...}：定義URL；
@{/order/process(execId=${execId},execType='FAST')}
Fragment Expressions: ~{...}：片段引用表達式
<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 ${name}|
Arithmetic operations:（數學運算）
Binary operators: + , - , * , / , %
Minus sign (unary operator): -
Boolean operations:（布爾運算）
Binary operators: and , or
Boolean negation (unary operator): ! , not
Comparisons and equality:（比較運算）
Comparators: > , < , >= , <= ( gt , lt , ge , le )
Equality operators: == , != ( eq , ne )
Conditional operators:條件運算（三元運算符）
If-then: (if) ? (then)
If-then-else: (if) ? (then) : (else)
Default: (value) ?: (defaultvalue)
Special tokens:
No-Operation: _
數據渲染到頁面相關用法：
html頁面：
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>跳轉成功頁面</h1>
<div th:text="${hello}"></div>
<hr/>
<div th:text="${hello}"></div>
<div th:utext="${hello}"></div>
<hr/>
<h4 th:text="${user}" th:each="user:${users}"></h4>
<hr/>
<h4>
<span th:each="user:${users}" > [[${user}]] </span>
</h4>
</body>
</html>
後端代碼：
@RequestMapping("/success")
public String success(Map<String,Object> map){
map.put("hello","你好");
map.put("users", Arrays.asList("張三","李四","王五"));
return "success";
}
效果圖：
