15 SpringBoot模板引擎

JSP、Velocity、Freemarker、Thymeleaf SpringBoot推荐的Thymeleaf； 语法更简单，功能更强大；

1、引入thymeleaf

2、Thymeleaf使用

只要我们把HTML页面放在classpath:/templates/，thymeleaf就能自动渲染； 使用： 1、导入thymeleaf的名称空间

2、使用thymeleaf语法；

3、语法规则

1）、th:text；改变当前元素里面的文本内容； th：任意html属性；来替换原生属性的值 2）、表达式？

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}：
	

		
Name: Sebastian.
		
Surname: Pepper.
		
Nationality: Saturn.
	
	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
	
...

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: > , < , >= ,