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 

        }
}

在春季> 4.1中使用SmartInitializingSingleton bean

@Bean
public SmartInitializingSingleton importProcessor() {
    return () -> {
        doStuff();
    };

}

作为备选方案，CommandLineRunner bean可以实现，也可以使用@PostConstruct注释bean方法。

为Dave Syer的回答提供了一个例子，这就像一个魅力:

@Component
public class CommandLineAppStartupRunner implements CommandLineRunner {
    private static final Logger logger = LoggerFactory.getLogger(CommandLineAppStartupRunner.class);

    @Override
    public void run(String...args) throws Exception {
        logger.info("Application started with command-line arguments: {} . \n To kill this application, press Ctrl + C.", Arrays.toString(args));
    }
}

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

    }
}

我非常喜欢@cahen (https://stackoverflow.com/a/44923402/9122660)对EventListener注释的使用建议，因为它非常干净。不幸的是，我不能让它在Spring + Kotlin设置中工作。对Kotlin有效的方法是将类作为方法参数添加:

@EventListener 
fun doSomethingAfterStartup(event: ApplicationReadyEvent) {
    System.out.println("hello world, I have just started up");
}