The best implementation method for timing tasks in java8 (implementation principle)

In Java 8, there are many ways to implement timing tasks, and each method has its applicable scenarios. Here are some common timing tasks implementations:

Class andkind
This is how timed task implementation provided by Java in the early days, but it is not thread-safe, and may affect the execution of subsequent tasks if the task is executed for a long time.

ScheduledExecutorService
This is a thread pool provided by Java concurrency packages that can be used to delay execution or perform tasks on a regular basis. It's betterTimerMore flexible and more recommended. The sample code is as follows:

ScheduledExecutorService scheduler = (1);
Runnable task = new Runnable() {
    @Override
    public void run() {
        // Task code    }
};
// Execute after 3 seconds, then execute every 2 seconds(task, 3, 2, );

DelayQueueis a blocking queue without boundaries, and elements can only be removed from the queue after the delay time has arrived. Suitable for tasks that require delayed execution.

DelayQueue<Runnable> queue = new DelayQueue<>();
Runnable task = new Runnable() {
    @Override
    public void run() {
        // Task code    }
};
// Put the task into the queue and execute after a delay of 1000 milliseconds.(new DelayedTask(task, 1000));

Spring framework@Scheduledannotation
If you are using Spring framework, you can use@ScheduledAnnotations to implement timing tasks. This method is simple and easy to use and integrates the rest of Spring's features well.

@Component
public class ScheduledTasks {
    @Scheduled(fixedRate = 5000)
    public void reportCurrentTime() {
        // Task code    }
}

Quartz Scheduler
Quartz is a powerful open source job scheduling library that can be integrated into almost any Java application. It provides a comparisonScheduledExecutorServiceMore complex scheduling requirements, such as Cron expressions.

JobDetail job = ()
    .withIdentity("myJob", "group1").build();
Trigger trigger = ()
    .withIdentity("myTrigger", "group1")
    .startNow()
    .withSchedule((10, 0))
    .build();
(job, trigger);

Akka Scheduler
If your application is based on the Akka framework, you can use Akka scheduler to implement timing tasks.

When choosing the best implementation method, you need to consider factors such as the complexity of the task, whether the integration framework is required, and whether cross-JVM scheduling is required. For most Java applications,ScheduledExecutorServiceIt is a simple and powerful choice, and for Spring applications, use@ScheduledAnnotations are more convenient. Quartz is a good choice for scheduling tasks that require highly configurable.

ScheduledExecutorServiceandTimerCompared with this, it has the following advantages:

Thread pool management：

ScheduledExecutorServiceIt is based on thread pools, which can reuse threads, improve efficiency, and adjust the size of the thread pool as needed.TimerThere is only one thread to execute all tasks. If there are more tasks or the task execution time is long, the tasks may be queued for execution.

Exception handling：

• existScheduledExecutorServiceIf an exception is thrown when one task is executed, it will not affect the execution of other tasks.
• TimerIf oneTimerTaskIf an exception is thrown, then subsequent tasks may not be executed.

flexibility：

• ScheduledExecutorServiceProvides more flexibility and can easily adjust the execution strategy of tasks, such as fixed frequency, fixed delay, single execution, etc.
• TimerThe functions are relatively limited and mainly support two types of scheduling:schedule(Single execution) andscheduleAtFixedRate(Fixed frequency execution).

Task cancellation and scheduling：

• ScheduledExecutorServiceAllows finer-grained task management and cancellation, which can cancel individual tasks or all tasks.
• TimerThere is no API to cancel a single task, only all tasks can be canceled.

Multithreaded support：

• ScheduledExecutorServiceIt is thread-safe and can be used in multi-threaded environments.
• TimerNot thread-safe and not suitable for multi-threaded environments.

Response interrupt：

• ScheduledExecutorServiceThe tasks in the()to respond to interrupts, which is very useful for tasks that require graceful shutdown.
• TimerNo such mechanism is provided.

Better API design：

• ScheduledExecutorServiceProvides more modern API designs, such as usingFutureto obtain the results of task execution, and can easily synchronize tasks.
• TimerThe API is relatively outdated and does not support such functions.

Cron expression support(via third-party library):

• AlthoughScheduledExecutorServiceCron expressions are not supported by itself, but Cron expressions can be dispatched through third-party libraries such as Quartz.

Resource Management：

• ScheduledExecutorServiceAllows better management of resources, such as setting up thread factories to set thread names, which is very useful for debugging and monitoring.

Overall,ScheduledExecutorServiceIt provides more powerful, flexible and reliable timing task scheduling capabilities, and is the recommended timing task implementation method in modern Java applications.

This is the end of this article about the best implementation of timed tasks in java 8. For more related java 8 timed tasks, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!