Spring Task定时任务的实现详解

@EnableScheduling //开启任务调度
@SpringBootApplication
public class UploadApplication {
    public static void main(String[] args) {
        SpringApplication.run(UploadApplication.class, args);
    }
}

//mapper
//获取僵尸token的id
List<Integer> selectDeadTokens();
//清除僵尸数据
int deleteDeadToken(@Param("ids") List<Integer> ids);

<delete id="deleteDeadToken">
       delete from imagetoken where id in
       <foreach collection="ids" item="e" open="(" separator="," close=")">
           #{e}
       </foreach>
</delete>
<select id="selectDeadTokens" resultType="java.lang.Integer">
        SELECT id FROM imagetoken t
        WHERE t.token NOT IN (select token FROM good)
</select>

//service 
@Transactional(propagation = Propagation.REQUIRED,isolation = Isolation.SERIALIZABLE)
    @Override
    public void deleteDeadToken() {
        System.out.println("---开始清除所有僵尸token---");
        List<Integer> list = imagetokenMapper.selectDeadTokens();
        System.out.println("已找到"+list.size()+"条数据");
        if (list.size()>0) {
            int result = imagetokenMapper.deleteDeadToken(list);
            System.out.println("本次删除"+result+"条数据");
        }
    }

 @Override
    public List<String> getList() {
        //条件构造器 查存放地址
        LambdaQueryWrapper<Good> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.select(Good::getSavepath);
        //this指的是当前service
        List<Good> list = this.list(queryWrapper);
//        System.out.println("查询到的数据:");
//        System.out.println(list);
        //获取数据库中所有图片的绝对路径List<String>
        ArrayList<String> paths = new ArrayList<>();
        //将查到的数据中的文件地址遍历到String类型的list中
        list.stream().forEach(good -> {
            paths.add(good.getSavepath());
        });
        //System.out.println("查到的路径:"+paths);
        return  paths;
    }

@Value("${image.savepath}")
    String savePath;
    /**
     * 每天晚上23点清除无效token数据并删除图片
     */
    @Scheduled(cron = "0 0 23 * * ?")
    public void delete(){
        //1.清除无效token
        imagetokenService.deleteDeadToken();
        //2.删除僵尸文件
        //2.1获取数据库中文件存储列表
        List<String> paths = goodService.getList();
        //2.2 获取图片存储地址
        File target=new File(savePath);
        //2.3遍历图片存储所在文件夹的文件
        File[] files=target.listFiles();
        for (File file : files) {
            if (file.isFile()){
                //2.4获取存储文件的绝对地址,需要将盘符修改,
                String absPath = file.getAbsolutePath().replaceAll("\\\\", "/");
                //2.5将不存在的文件删除
                if(!paths.contains(absPath)){
                     //System.out.println("要删除文件的觉得路径:"+absPath);
                     file.delete();
                 }
            }
        }
    }