<!--模板引擎-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

thymeleaf:  #thymeleaf配置
    cache: false
    prefix: classpath:/WEB-INF/view/
    suffix: .html
    encoding: UTF-8
    content-type: text/html
    mode: html5
mvc:
    static-path-pattern: /WEB-INF/view/**  # 静态资源路径

1.添加依赖
<!--启用不严格检查html-->
        <dependency>
            <groupId>net.sourceforge.nekohtml</groupId>
            <artifactId>nekohtml</artifactId>
            <version>1.9.22</version>
        </dependency>
2.修改配置文件，将mode参数改成这样既可
thymeleaf:
    mode: LEGACYHTML5