监听器

监听器：文件/文件夹

当文件/文件夹发生新增或删除就会出发监听器
并可以设置相关操作
比如视频快照，每个照片都要进行算法识别，可以监听该文件夹，一旦有新照片创建，自动调用算法接口。

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.monitor.FileAlterationListenerAdaptor;
import org.apache.commons.io.monitor.FileAlterationMonitor;
import org.apache.commons.io.monitor.FileAlterationObserver;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.event.ApplicationReadyEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

import javax.annotation.Resource;
import java.io.File;
import java.util.List;

//@Component
@Slf4j
public class InitFFmpeg implements ApplicationListener<ApplicationReadyEvent> {


    @Override
    public void onApplicationEvent(ApplicationReadyEvent event) {
     
        runExample("需要监听的 文件/文件夹 URL");

    }

    public void runExample(String PARENT_DIR) throws java.lang.Exception {

        File parentDir = FileUtils.getFile(PARENT_DIR);

        FileAlterationObserver observer = new FileAlterationObserver(parentDir);
        observer.addListener(new FileAlterationListenerAdaptor() {

            @Override
            public void onFileCreate(File file) {
    
            }

            @Override
            public void onFileDelete(File file) {

            }

            @Override
            public void onDirectoryCreate(File dir) {
                System.out.println("Directory created: " + dir.getName());
            }

            @Override
            public void onDirectoryDelete(File dir) {
                System.out.println("Directory deleted: " + dir.getName());
            }
        });

        FileAlterationMonitor monitor = new FileAlterationMonitor(500, observer);

        monitor.start();
    }
}