Spring 引导 Web 应用程序不以模块信息启动

Question

我想通过 java 9+ 之类的模块学习一些新东西。
所以我用spring-boot-starter-web和module-info.java创建了一个 spring 引导应用程序：

module com.example.demo {
    requires spring.boot;
    requires spring.boot.autoconfigure;

    exports com.example.demo;
    opens com.example.demo;
}

我用了
-> Java 15.0.2
-> Spring 启动 2.4.3
-> IntelliJ IDE 2020.3
-> Ubuntu 20.04.2 LTS

---

为了运行应用程序，我在 IntelliJ 中使用了一个运行按钮（绿色箭头）——默认运行，没有任何额外的参数。 问题是当我尝试运行应用程序时，嵌入式 tomcat 服务器无法启动。
Output with module-info.java

2021-03-12 08:57:12.182  INFO 4843 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication using Java 15.0.2 on vagrant-VirtualBox with PID 4843 
2021-03-12 08:57:12.184  INFO 4843 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default
2021-03-12 08:57:13.081  INFO 4843 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 1.511 seconds (JVM running for 3.418)  

但是，当我删除module-info.java时，一切正常，tomcat 服务器启动。
Output 不带模块信息。java

2021-03-12 09:01:49.627  INFO 4928 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication using Java 15.0.2 on vagrant-VirtualBox with PID 4928 
2021-03-12 09:01:49.633  INFO 4928 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default
2021-03-12 09:01:50.897  INFO 4928 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2021-03-12 09:01:50.912  INFO 4928 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2021-03-12 09:01:50.912  INFO 4928 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.43]
2021-03-12 09:01:50.958  INFO 4928 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2021-03-12 09:01:50.958  INFO 4928 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1188 ms
2021-03-12 09:01:51.179  INFO 4928 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2021-03-12 09:01:51.320  INFO 4928 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2021-03-12 09:01:51.329  INFO 4928 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 2.271 seconds (JVM running for 3.774)

我想知道输出之间的区别。 当我使用module-info.java Tomcat 不运行时，因为它超出了我的模块？

我可以做些什么来运行应用程序？

您如何看待，将 java 模块与 Spring 引导一起使用是否有意义？ 为什么？ 为什么不？

Answer 1

需要添加requires org.apache.tomcat.embed.core; in modules-info.java to include org.apache.catalina.startup.Tomcat.class , see this article for details on how Spring boot start the tomcat server.