主要原因是依赖产生的错误：
错误提示，解决方法如下所示
| Mango Application | version: 1.0|
2021-09-26 10:12:17.741 INFO 16680 --- [ main] com.louis.mango.MangoApplication : Starting MangoApplication using Java 11.0.2 on hxdcomouter with PID 16680 (F:\springboot\mango\target\classes started by HXD in F:\springboot\mango)
2021-09-26 10:12:17.743 INFO 16680 --- [ main] com.louis.mango.MangoApplication : No active profile set, falling back to default profiles: default
2021-09-26 10:12:18.342 INFO 16680 --- [ main] com.louis.mango.MangoApplication : Started MangoApplication in 1.188 seconds (JVM running for 1.65)
项目目录结构：
打开pom.xml配置文件如下所示：
改成 ：<artifactId>spring-boot-starter-web</artifactId>
如下图所示：
所有代码以及运行中产生的错误来自下书中
