尝试这个方法，它将在应用程序上下文完全启动时运行您的代码。

 @Component
public class OnStartServer implements ApplicationListener<ContextRefreshedEvent> {

    @Override
    public void onApplicationEvent(ContextRefreshedEvent arg0) {
                // EXECUTE YOUR CODE HERE 
    }
}

为spring boot应用程序实现CommandLineRunner。 你需要实现run方法，

public classs SpringBootApplication implements CommandLineRunner{

    @Override
        public void run(String... arg0) throws Exception {
        // write your logic here 

        }
}

你试过ApplicationReadyEvent吗?

@Component
public class ApplicationStartup 
implements ApplicationListener<ApplicationReadyEvent> {

  /**
   * This event is executed as late as conceivably possible to indicate that 
   * the application is ready to service requests.
   */
  @Override
  public void onApplicationEvent(final ApplicationReadyEvent event) {

    // here your code ...

    return;
  }
}

代码来自:http://blog.netgloo.com/2014/11/13/run-code-at-spring-boot-startup/

下面是文档中提到的启动事件:

... Application events are sent in the following order, as your application runs: An ApplicationStartedEvent is sent at the start of a run, but before any processing except the registration of listeners and initializers. An ApplicationEnvironmentPreparedEvent is sent when the Environment to be used in the context is known, but before the context is created. An ApplicationPreparedEvent is sent just before the refresh is started, but after bean definitions have been loaded. An ApplicationReadyEvent is sent after the refresh and any related callbacks have been processed to indicate the application is ready to service requests. An ApplicationFailedEvent is sent if there is an exception on startup. ...

使用CommandLineRunner或ApplicationRunner的最佳方式 两者之间唯一的区别是run()方法 CommandLineRunner接受字符串数组，ApplicationRunner接受应用参数。

如果你的意思是在应用程序启动后运行一次peace of code，你可以如下所示使用CommandLineRunner:

@SpringBootApplication
public class SpringBootApplication 
  implements CommandLineRunner {

private static Logger LOG = LoggerFactory
  .getLogger(SpringBootConsoleApplication.class);

public static void main(String[] args) {
    LOG.info("STARTING THE APPLICATION");
    SpringApplication.run(SpringBootConsoleApplication.class, args);
    LOG.info("APPLICATION FINISHED");
}

@Override
public void run(String... args) {
    // enter code you want to run after app loaded here
    LOG.info("EXECUTING : command line runner");

    for (int i = 0; i < args.length; ++i) {
        LOG.info("args[{}]: {}", i, args[i]);
    }
}

}

否则，您可以使用DevTools依赖项，它可以帮助您在不手动重新启动应用程序的情况下运行新代码。

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
    </dependency>
</dependencies>

不要忘记将这些代码添加到pom.xml中，以避免版本警告:

   <properties>
        <java.version>17</java.version>
        <spring-cloud.version>2021.0.3</spring-cloud.version>
    </properties>

 <dependencies>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>${spring-cloud.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>

如果这对你有帮助，给它一个重击!

您可以使用ApplicationRunner扩展类，重写run()方法并在那里添加代码。

import org.springframework.boot.ApplicationRunner;

@Component
public class ServerInitializer implements ApplicationRunner {

    @Override
    public void run(ApplicationArguments applicationArguments) throws Exception {

        //code goes here

    }
}