IDEA 快速搭建 SpringBoot 环境时，编写controller后启动没有任何反应

IDEA 快速搭建 SpringBoot 环境时，一切就绪，点击运行按钮，结果并没有任何反应。

E:\javahome\Java\jdk1.8.0_221\bin\java -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=5817 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=localhost -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2017.3.4\lib\idea_rt.jar=5818:C:\Program Files\JetBrains\IntelliJ IDEA 2017.3.4\bin" -Dfile.encoding=UTF-8 -classpath E:\javahome\Java\jdk1.8.0_221\jre\lib\charsets.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\deploy.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\access-bridge-64.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\cldrdata.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\dnsns.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\jaccess.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\jfxrt.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\localedata.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\nashorn.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\sunec.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\sunjce_provider.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\sunmscapi.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\sunpkcs11.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\ext\zipfs.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\javaws.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\jce.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\jfr.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\jfxswt.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\jsse.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\management-agent.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\plugin.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\resources.jar;E:\javahome\Java\jdk1.8.0_221\jre\lib\rt.jar;D:\WorkSpace\IDEA\SpringBoot\demo2\target\classes;D:\Document\maven_repo\org\springframework\boot\spring-boot-starter-web\2.3.4.RELEASE\spring-boot-starter-web-2.3.4.RELEASE.jar;D:\Document\maven_repo\org\springframework\boot\spring-boot-starter\2.3.4.RELEASE\spring-boot-starter-2.3.4.RELEASE.jar;D:\Document\maven_repo\org\springframework\boot\spring-boot\2.3.4.RELEASE\spring-boot-2.3.4.RELEASE.jar;D:\Document\maven_repo\org\springframework\boot\spring-boot-autoconfigure\2.3.4.RELEASE\spring-boot-autoconfigure-2.3.4.RELEASE.jar;D:\Document\maven_repo\org\springframework\boot\spring-boot-starter-logging\2.3.4.RELEASE\spring-boot-starter-logging-2.3.4.RELEASE.jar;D:\Document\maven_repo\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;D:\Document\maven_repo\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;D:\Document\maven_repo\org\apache\logging\log4j\log4j-to-slf4j\2.13.3\log4j-to-slf4j-2.13.3.jar;D:\Document\maven_repo\org\apache\logging\log4j\log4j-api\2.13.3\log4j-api-2.13.3.jar;D:\Document\maven_repo\org\slf4j\jul-to-slf4j\1.7.30\jul-to-slf4j-1.7.30.jar;D:\Document\maven_repo\org\yaml\snakeyaml\1.26\snakeyaml-1.26.jar;D:\Document\maven_repo\org\springframework\boot\spring-boot-starter-json\2.3.4.RELEASE\spring-boot-starter-json-2.3.4.RELEASE.jar;D:\Document\maven_repo\com\fasterxml\jackson\core\jackson-databind\2.11.2\jackson-databind-2.11.2.jar;D:\Document\maven_repo\com\fasterxml\jackson\core\jackson-annotations\2.11.2\jackson-annotations-2.11.2.jar;D:\Document\maven_repo\com\fasterxml\jackson\core\jackson-core\2.11.2\jackson-core-2.11.2.jar;D:\Document\maven_repo\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.11.2\jackson-datatype-jdk8-2.11.2.jar;D:\Document\maven_repo\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.11.2\jackson-datatype-jsr310-2.11.2.jar;D:\Document\maven_repo\com\fasterxml\jackson\module\jackson-module-parameter-names\2.11.2\jackson-module-parameter-names-2.11.2.jar;D:\Document\maven_repo\org\springframework\spring-web\5.2.9.RELEASE\spring-web-5.2.9.RELEASE.jar;D:\Document\maven_repo\org\springframework\spring-beans\5.2.9.RELEASE\spring-beans-5.2.9.RELEASE.jar;D:\Document\maven_repo\org\springframework\spring-webmvc\5.2.9.RELEASE\spring-webmvc-5.2.9.RELEASE.jar;D:\Document\maven_repo\org\springframework\spring-aop\5.2.9.RELEASE\spring-aop-5.2.9.RELEASE.jar;D:\Document\maven_repo\org\springframework\spring-context\5.2.9.RELEASE\spring-context-5.2.9.RELEASE.jar;D:\Document\maven_repo\org\springframework\spring-expression\5.2.9.RELEASE\spring-expression-5.2.9.RELEASE.jar;D:\Document\maven_repo\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;D:\Document\maven_repo\org\slf4j\slf4j-api\1.7.30\slf4j-api-1.7.30.jar;D:\Document\maven_repo\org\springframework\spring-core\5.2.9.RELEASE\spring-core-5.2.9.RELEASE.jar;D:\Document\maven_repo\org\springframework\spring-jcl\5.2.9.RELEASE\spring-jcl-5.2.9.RELEASE.jar com.example.demo2.Demo2Application

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.3.4.RELEASE)

2020-09-24 15:54:39.085  INFO 11184 --- [           main] com.example.demo2.Demo2Application       : Starting Demo2Application on DESKTOP-ALARULH with PID 11184 (D:\WorkSpace\IDEA\SpringBoot\demo2\target\classes started by llf in D:\WorkSpace\IDEA\SpringBoot\demo2)
2020-09-24 15:54:39.087  INFO 11184 --- [           main] com.example.demo2.Demo2Application       : No active profile set, falling back to default profiles: default
2020-09-24 15:54:39.681  INFO 11184 --- [           main] com.example.demo2.Demo2Application       : Started Demo2Application in 1.024 seconds (JVM running for 2.255)

Process finished with exit code 0

最开始创建工程的时候，选择的是让工程打包成 war 形式。
正确的做法是：选择选项打包成 jar 包

经过测试，的确是因为 war 选择问题。