Spring启动动态添加新的计划作业

Question

我正在写一个Spring Boot App

我的要求是 - 在资源(src/main/resources)文件夹中,如果我添加新的xml文件..我应该阅读这些文件,并从每个文件中获取一些网址和其他特定设置.对于那些我需要每天下载数据的网址.所以新的调度程序作业将从url和一些设置开始

新作业将在不同的计划时间运行,这将使用xml文件中存在的cron表达式.还将在任何时间点动态添加文件如何实现它.

Answer 1

如果您想动态安排任务,可以在没有弹簧的情况下使用ExecutorService,特别是ScheduledThreadPoolExecutor

Runnable task  = () -> doSomething();
ScheduledExecutorService executor = Executors.newScheduledThreadPool(Runtime.getRuntime().availableProcessors());
// Schedule a task that will be executed in 120 sec
executor.schedule(task, 120, TimeUnit.SECONDS);

// Schedule a task that will be first run in 120 sec and each 120sec
// If an exception occurs then it's task executions are canceled.
executor.scheduleAtFixedRate(task, 120, 120, TimeUnit.SECONDS);

// Schedule a task that will be first run in 120 sec and each 120sec after the last execution
// If an exception occurs then it's task executions are canceled.
executor.scheduleWithFixedDelay(task, 120, 120, TimeUnit.SECONDS);

使用spring,您可以依赖Task和Scheduling API

public class MyBean {

    private final TaskScheduler executor;

    @Autowired
    public MyBean(TaskScheduler taskExecutor) {
        this.executor = taskExecutor;
    }

    public void scheduling(final Runnable task) {
        // Schedule a task to run once at the given date (here in 1minute)
        executor.schedule(task, Date.from(LocalDateTime.now().plusMinutes(1)
            .atZone(ZoneId.systemDefault()).toInstant()));

        // Schedule a task that will run as soon as possible and every 1000ms
        executor.scheduleAtFixedRate(task, 1000);

        // Schedule a task that will first run at the given date and every 1000ms
        executor.scheduleAtFixedRate(task, Date.from(LocalDateTime.now().plusMinutes(1)
            .atZone(ZoneId.systemDefault()).toInstant()), 1000);

        // Schedule a task that will run as soon as possible and every 1000ms after the previous completion
        executor.scheduleWithFixedDelay(task, 1000);

        // Schedule a task that will run as soon as possible and every 1000ms after the previous completion
        executor.scheduleWithFixedDelay(task, Date.from(LocalDateTime.now().plusMinutes(1)
            .atZone(ZoneId.systemDefault()).toInstant()), 1000);

        // Schedule a task with the given cron expression
        executor.schedule(task, new CronTrigger("*/5 * * * * MON-FRI"));
    }
}

您可以通过实现Trigger来提供自己的触发器

不要忘记在配置类上使用@EnableScheduling启用调度.

关于监听目录内容,您可以使用WatchService.就像是:

final Path myDir = Paths.get("my/directory/i/want/to/monitor");
final WatchService watchService = FileSystems.getDefault().newWatchService();
// listen to create event in the directory
myDir.register(watchService, StandardWatchEventKinds.ENTRY_CREATE);
// Infinite loop don't forget to run this in a Thread
for(;;) {
   final WatchKey key = watchService.take();
   for (WatchEvent<?> event : key.pollEvents()) {
       WatchEvent<Path> watchEvent = (WatchEvent<Path>) event;
       Path newFilePath = myDir.resolve(watchEvent.context());
       //do something with the newFilePath
    }
    // To keep receiving event
    key.reset();
}

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