springboot學習之Thymeleaf模板引擎及原理介紹
模板引擎
springboot我們目前是以jar包的形式打包,實際上我們之前是打成war包,放到tomcat服務器裡面,可以用JSP。
但是jar包就導致不能用JSP,換一種方式就是springboot推薦的Thymeleaf模板引擎(JSP也是一種模板引擎,除此之外還有什麼framework也是一種模板引擎),
什麼是模板引擎?
模板引擎就是解決我們需要動態賦值給前端的一種解決方案
(模板引擎的作用就是我們來寫一個頁面模板,比如有些值呢,是動態的,我們寫一些表達式。而這些值,從哪來呢,就是我們在後臺封裝一些數據。然後把這個模板和這個數據交給我們模板引擎,模板引擎按照我們這個數據幫你把這表達式解析、填充到我們指定的位置,然後把這個數據最終生成一個我們想要的內容給我們寫出去,這就是我們這個模板引擎,不管是jsp還是其他模板引擎,都是這個思想。隻不過呢,就是說不同模板引擎之間,他們可能這個語法有點不一樣。其他的我就不介紹瞭,我主要來介紹一下SpringBoot給我們推薦的Thymeleaf模板引擎,這模板引擎呢,是一個高級語言的模板引擎,他的這個語法更簡單。而且呢,功能更強大。)
模板引擎的原理
引入Thymeleaf
引入就是導入依賴,以下是網址是相關的地址
Thymeleaf 官網:https://www.thymeleaf.org/
Thymeleaf 在Github 的主頁:https://github.com/thymeleaf/thymeleaf
Spring官方文檔:找到我們對應的版本
https://docs.spring.io/spring-boot/docs/2.2.5.RELEASE/reference/htmlsingle/#using-boot-starter
找到對應的pom依賴:可以適當點進源碼看下本來的包!
<!--thymeleaf--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency>
Thymeleaf分析
Thymeleaf的引入依賴文件ThymeleafProperties,文件內容如下:
// IntelliJ API Decompiler stub source generated from a class file // Implementation of methods is not available package org.springframework.boot.autoconfigure.thymeleaf; @org.springframework.boot.context.properties.ConfigurationProperties(prefix = "spring.thymeleaf") public class ThymeleafProperties { private static final java.nio.charset.Charset DEFAULT_ENCODING; public static final java.lang.String DEFAULT_PREFIX = "classpath:/templates/"; public static final java.lang.String DEFAULT_SUFFIX = ".html"; private boolean checkTemplate; private boolean checkTemplateLocation; private java.lang.String prefix; private java.lang.String suffix; private java.lang.String mode; private java.nio.charset.Charset encoding; private boolean cache; private java.lang.Integer templateResolverOrder; private java.lang.String[] viewNames; private java.lang.String[] excludedViewNames; private boolean enableSpringElCompiler; private boolean renderHiddenMarkersBeforeCheckboxes; private boolean enabled; private final org.springframework.boot.autoconfigure.thymeleaf.ThymeleafProperties.Servlet servlet; private final org.springframework.boot.autoconfigure.thymeleaf.ThymeleafProperties.Reactive reactive; public ThymeleafProperties() { /* compiled code */ } public boolean isEnabled() { /* compiled code */ } public void setEnabled(boolean enabled) { /* compiled code */ } public boolean isCheckTemplate() { /* compiled code */ } public void setCheckTemplate(boolean checkTemplate) { /* compiled code */ } public boolean isCheckTemplateLocation() { /* compiled code */ } public void setCheckTemplateLocation(boolean checkTemplateLocation) { /* compiled code */ } public java.lang.String getPrefix() { /* compiled code */ } public void setPrefix(java.lang.String prefix) { /* compiled code */ } public java.lang.String getSuffix() { /* compiled code */ } public void setSuffix(java.lang.String suffix) { /* compiled code */ } public java.lang.String getMode() { /* compiled code */ } public void setMode(java.lang.String mode) { /* compiled code */ } public java.nio.charset.Charset getEncoding() { /* compiled code */ } public void setEncoding(java.nio.charset.Charset encoding) { /* compiled code */ } public boolean isCache() { /* compiled code */ } public void setCache(boolean cache) { /* compiled code */ } public java.lang.Integer getTemplateResolverOrder() { /* compiled code */ } public void setTemplateResolverOrder(java.lang.Integer templateResolverOrder) { /* compiled code */ } public java.lang.String[] getExcludedViewNames() { /* compiled code */ } public void setExcludedViewNames(java.lang.String[] excludedViewNames) { /* compiled code */ } public java.lang.String[] getViewNames() { /* compiled code */ } public void setViewNames(java.lang.String[] viewNames) { /* compiled code */ } public boolean isEnableSpringElCompiler() { /* compiled code */ } public void setEnableSpringElCompiler(boolean enableSpringElCompiler) { /* compiled code */ } public boolean isRenderHiddenMarkersBeforeCheckboxes() { /* compiled code */ } public void setRenderHiddenMarkersBeforeCheckboxes(boolean renderHiddenMarkersBeforeCheckboxes) { /* compiled code */ } public org.springframework.boot.autoconfigure.thymeleaf.ThymeleafProperties.Reactive getReactive() { /* compiled code */ } public org.springframework.boot.autoconfigure.thymeleaf.ThymeleafProperties.Servlet getServlet() { /* compiled code */ } public static class Reactive { private org.springframework.util.unit.DataSize maxChunkSize; private java.util.List<org.springframework.http.MediaType> mediaTypes; private java.lang.String[] fullModeViewNames; private java.lang.String[] chunkedModeViewNames; public Reactive() { /* compiled code */ } public java.util.List<org.springframework.http.MediaType> getMediaTypes() { /* compiled code */ } public void setMediaTypes(java.util.List<org.springframework.http.MediaType> mediaTypes) { /* compiled code */ } public org.springframework.util.unit.DataSize getMaxChunkSize() { /* compiled code */ } public void setMaxChunkSize(org.springframework.util.unit.DataSize maxChunkSize) { /* compiled code */ } public java.lang.String[] getFullModeViewNames() { /* compiled code */ } public void setFullModeViewNames(java.lang.String[] fullModeViewNames) { /* compiled code */ } public java.lang.String[] getChunkedModeViewNames() { /* compiled code */ } public void setChunkedModeViewNames(java.lang.String[] chunkedModeViewNames) { /* compiled code */ } } public static class Servlet { private org.springframework.util.MimeType contentType; private boolean producePartialOutputWhileProcessing; public Servlet() { /* compiled code */ } public org.springframework.util.MimeType getContentType() { /* compiled code */ } public void setContentType(org.springframework.util.MimeType contentType) { /* compiled code */ } public boolean isProducePartialOutputWhileProcessing() { /* compiled code */ } public void setProducePartialOutputWhileProcessing(boolean producePartialOutputWhileProcessing) { /* compiled code */ } }
我們可以在其中看到默認的前綴和後綴。
我們隻需要把我們的html頁面放在類路徑下的templates下,thymeleaf就可以幫我們自動渲染瞭。
啟動訪問結果
Thymeleaf 語法學習
要學習語法,還是參考官網文檔最為準確,我們找到對應的版本看一下;
Thymeleaf 官網:https://www.thymeleaf.org/ , 簡單看一下官網!我們去下載Thymeleaf的官方文檔!
做一個最簡單的向頁面傳值操作
(1)寫一個頁面,一個msg來作為傳值
<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org"> <head> <meta charset="UTF-8"> <title>ZP</title> </head> <body> <h1>測試頁面</h1> <!--th:text就是將div中的內容設置為它指定的值,和之前學習的Vue一樣--> <div th:text="${msg}"></div> </body> </html>
代碼
註意這裡return的字符串要和上面的templates下面的html文件名字相同。
package com.example.zpspringboot3.controller; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; /** * @Author: zhangpeng * @Date: 2022/2/21 16:02 */ @Controller public class TestController { // @RequestMapping("/t1") // public String test1(){ // //classpath:/templates/test.html // return "text"; // } @RequestMapping("/t1") public String test1(Model model){ //存入數據 model.addAttribute("msg","Hello,Thymeleaf"); //classpath:/templates/test.html return "text2"; } }
測試
通過thymeleaf官網文檔學習一些語法:
1、我們可以使用任意的 th:attr 來替換Html中原生屬性的值!
2、我們能寫哪些表達式呢?
Simple expressions:(表達式語法) Variable Expressions: ${...}:獲取變量值;OGNL; 1)、獲取對象的屬性、調用方法 2)、使用內置的基本對象:#18 #ctx : the context object. #vars: the context variables. #locale : the context locale. #request : (only in Web Contexts) the HttpServletRequest object. #response : (only in Web Contexts) the HttpServletResponse object. #session : (only in Web Contexts) the HttpSession object. #servletContext : (only in Web Contexts) the ServletContext object. 3)、內置的一些工具對象: #execInfo : information about the template being processed. #uris : methods for escaping parts of URLs/URIs #conversions : methods for executing the configured conversion service (if any). #dates : methods for java.util.Date objects: formatting, component extraction, etc. #calendars : analogous to #dates , but for java.util.Calendar objects. #numbers : methods for formatting numeric objects. #strings : methods for String objects: contains, startsWith, prepending/appending, etc. #objects : methods for objects in general. #bools : methods for boolean evaluation. #arrays : methods for arrays. #lists : methods for lists. #sets : methods for sets. #maps : methods for maps. #aggregates : methods for creating aggregates on arrays or collections. ================================================================================== Selection Variable Expressions: *{...}:選擇表達式:和${}在功能上是一樣; Message Expressions: #{...}:獲取國際化內容 Link URL Expressions: @{...}:定義URL; Fragment Expressions: ~{...}:片段引用表達式 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 ${name}| Arithmetic operations:(數學運算) Binary operators: + , - , * , / , % Minus sign (unary operator): - Boolean operations:(佈爾運算) Binary operators: and , or Boolean negation (unary operator): ! , not Comparisons and equality:(比較運算) Comparators: > , < , >= , <= ( gt , lt , ge , le ) Equality operators: == , != ( eq , ne ) Conditional operators:條件運算(三元運算符) If-then: (if) ? (then) If-then-else: (if) ? (then) : (else) Default: (value) ?: (defaultvalue) Special tokens: No-Operation: _
練習測試:
1、 我們編寫一個Controller,放一些數據
@RequestMapping("/t2") public String test2(Map<String,Object> map){ //存入數據 map.put("msg","<h1>Hello</h1>"); map.put("users", Arrays.asList("zp","zhangpeng")); //classpath:/templates/test.html return "text3"; }
<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org"> <head> <meta charset="UTF-8"> <title>狂神說</title> </head> <body> <h1>測試頁面</h1> <div th:text="${msg}"></div> <!--不轉義--> <div th:utext="${msg}"></div> <!--遍歷數據--> <!--th:each每次遍歷都會生成當前這個標簽:官網#9--> <h4 th:each="user :${users}" th:text="${user}"></h4> <h4> <!--行內寫法:官網#12--> <span th:each="user:${users}">[[${user}]]</span> </h4> </body> </html>
到此這篇關於springboot學習Thymeleaf模板引擎的文章就介紹到這瞭,更多相關springboot Thymeleaf模板引擎內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet!
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