模板引擎

thymeleaf 依赖

	<groupId>org.thymeleaf</groupId>
	<artifactId>thymeleaf-spring5</artifactId>
	<version>3.0.11.RELEASE</version>
	</dependency>
   <dependency>
	<groupId>org.thymeleaf.extras</groupId>
	<artifactId>thymeleaf-extras-java8time</artifactId>
	<version>3.0.4.RELEASE</version>
</dependency>xml```
> 
html页面的  约束`xmlns:th="http://www.thymeleaf.org"`