已添加：

   <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-freemarker</artifactId>

        </dependency>

还是访问不了@Controller标注的WechatController类

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Sun May 06 21:10:05 CST 2018

There was an unexpected error (type=Bad Request, status=400).

Required String parameter 'returnUrl ' is not present