有时候我们需要在spring boot容器启动并加载完后，开一些线程或者一些程序来干某些事情。这时候我们需要配置ContextRefreshedEvent事件来实现我们要做的事情

1、ApplicationStartup类

public class ApplicationStartup implements ApplicationListener<ContextRefreshedEvent>{
    public void onApplicationEvent(ContextRefreshedEvent event)
      {
        //在容器加载完毕后获取dao层来操作数据库
        OSSVideoRepository ossVideoRepository = (OSSVideoRepository)event.getApplicationContext().getBean(OSSVideoRepository.class);
        //在容器加载完毕后获取配置文件中的配置
        ServerConfig serverConfig = (ServerConfig)event.getApplicationContext().getBean(ServerConfig.class);
        
        ServerFileScanner fileScanner = new ServerFileScanner(
                ossVideoRepository, serverConfig.getScanpath());
        //在容器加载完毕后启动线程
        Thread thread = new Thread(fileScanner);
        thread.start();
      }
}

2、ServerConfig 类

@Component
@ConfigurationProperties(prefix = "server")
public class ServerConfig {
    private String aliyunossEndpoint;
    private String aliyunossAccessKeyId;
    private String aliyunossAccessKeySecret;
    private String aliyunossBucketName;
    private String scanpath;

    public String getAliyunossEndpoint() {
        return aliyunossEndpoint;
    }

    public void setAliyunossEndpoint(String aliyunossEndpoint) {
        this.aliyunossEndpoint = aliyunossEndpoint;
    }

    public String getAliyunossAccessKeyId() {
        return aliyunossAccessKeyId;
    }

    public void setAliyunossAccessKeyId(String aliyunossAccessKeyId) {
        this.aliyunossAccessKeyId = aliyunossAccessKeyId;
    }

    public String getAliyunossAccessKeySecret() {
        return aliyunossAccessKeySecret;
    }

    public void setAliyunossAccessKeySecret(String aliyunossAccessKeySecret) {
        this.aliyunossAccessKeySecret = aliyunossAccessKeySecret;
    }

    public String getAliyunossBucketName() {
        return aliyunossBucketName;
    }

    public void setAliyunossBucketName(String aliyunossBucketName) {
        this.aliyunossBucketName = aliyunossBucketName;
    }

    public String getScanpath() {
        return scanpath;
    }

    public void setScanpath(String scanpath) {
        this.scanpath = scanpath;
    }

}

PS：还有一些spring内置的事件

1、 ContextRefreshedEvent：ApplicationContext容器初始化或者刷新时触发该事件。
2、 ContextStartedEvent：当使用ConfigurableApplicationContext接口的start()方法启动ApplicationContext容器时触发该事件。
3、 ContextClosedEvent：当使用ConfigurableApplicationContext接口的close()方法关闭ApplicationContext容器时触发该事件。
4、 ContextStopedEvent: 当使用ConfigurableApplicationContext接口的stop()方法停止ApplicationContext容器时触发该事件。

有兴趣可以都研究研究