应用程序在外部 Tomcat 上启动之前的 Spring Boot 日志记录

Question

每当 Spring Boot 应用程序即将启动时，我都会尝试进行一些日志记录。

目前我有一个实现ApplicationEnvironmentPreparedEvent 的类，我在SpringBootApplication 的主函数中将其注册为监听器。

Application.java：

@SpringBootApplication
public class Application extends SpringBootServletInitializer {
    private static final Logger appLogger = LoggerFactory.getLogger(Application.class);
    public static void main(String[] args) {
        System.out.println("INIT");
        appLogger.info("Initializing");

        SpringApplication sa = new SpringApplication();
        sa.addListeners(new InitializationLogger());
        sa.setSources(new HashSet<>(Collections.singletonList(Application.class)));
        sa.run(args);

        appLogger.info("--Application Started--");
    }
}

InitializationLogger.java

public class InitializationLogger implements ApplicationListener<ApplicationEnvironmentPreparedEvent> {
    private static final Logger appLogger = LoggerFactory.getLogger(InitializationLogger.class);

    @Override
    public void onApplicationEvent(ApplicationEnvironmentPreparedEvent event) {
        System.out.println(event.getClass());
        appLogger.info(this.getClass().getName());
    }
}

问题是，每当我通过 Intellij 的 SpringBoot 运行器或命令行作为胖 jar 运行应用程序时，它都可以正常工作，但是当我将其部署到外部 Tomcat 时，这些日志不会显示（所有其他应用程序日志工作正常）。

我该怎么做？

Answer 1

我该怎么做？

覆盖SpringBootServletInitializer.configure，类似于：

@SpringBootApplication
public class Application extends SpringBootServletInitializer {
    private static final Logger appLogger = LoggerFactory.getLogger(Application.class);

    // for JAR deploy:
    public static void main(String[] args) {
        SpringApplicationBuilder builder = configureSpringBuilder(new SpringApplicationBuilder());
        builder.application().run(args);
        appLogger.info("--Application Started--");
    }

    // for WAR deploy:
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return super.configure(configureSpringBuilder(builder));
    }

    // Common:
    private static SpringApplicationBuilder configureSpringBuilder(SpringApplicationBuilder builder) {
        System.out.println("INIT");
        appLogger.info("Initializing");

        builder.application().addListeners(new InitializationLogger());
        builder.application().setSources(new HashSet<>(Collections.singletonList(Application.class)));

        return builder;
    }
}

参考资料：

1. Class SpringBootServletInitializer

   要配置应用程序，请覆盖 configure(SpringApplicationBuilder) 方法 (...)

2. Tutorial: Use Spring Boot to Build and Deploy WAR Files - Setting Up a Servlet

   要将应用设置为 servlet，我们使用 SpringBootServletInitializer 扩展主类并使用 SpringApplicationBuilder 覆盖配置方法。

3. Deploying Spring Boot Applications - What about the Java EE Application Server?

   因此修改您的应用程序入口点类 (...)