一：创建spring boot的web项目，过程略；

二：依赖如下：

      org.springframework.boot
      spring-boot-starter-web
    
 
    
      org.springframework.boot
      spring-boot-starter-thymeleaf
      2.1.2.RELEASE
    
 
    
      org.springframework.boot
      spring-boot-starter-test
      test
      
        
          org.junit.vintage
          junit-vintage-engine
        
      
    

三：配置文件：application.properties

#端口号
server.port=8099
# 配置
#thymeleaf
spring.thymeleaf.cache=false
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.check-template-location=true
spring.thymeleaf.suffix=.html
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.servlet.content-type=text/html
spring.thymeleaf.mode=HTML

四：项目的templates文件夹下新建页面success.html，如下

五：controller

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
 
/**
 * @author liuhongyang
 * @2020/10/20 14:35
 * 文件说明：
 */
@Controller
public class FirstTestController {
 
  @RequestMapping(value = "hello")
  public String hello(ModelMap modelMap) {
    modelMap.put("hei", "thymeleaf");
    return "success";
  }
}

六：访问如下，完成