How to use thread pool in Java 7 to implement periodic execution of tasks and result processing

How to use thread pools in Java 7 to implement periodic execution of tasks and result processing

In multi-threaded programming, thread pools are a commonly used technology that can effectively manage the creation of threads and destruction to improve program performance and efficiency. In Java 7, the Executor framework can easily implement a thread pool and perform periodic execution of tasks and result processing. This article describes how to use thread pools to implement these functions, along with corresponding code examples.

1. Establishing a thread pool

In Java, you can use the ExecutorService interface to create and manage a thread pool. The simplest way is to use one of the static methods of the Executors class. For example, you can use the Executors.newFixedThreadPool(int n) method to create a fixed-size thread pool, where n represents the number of threads.

ExecutorService executor = Executors.newFixedThreadPool(5);

2. Execute the task

Next, the task can be submitted to the thread pool for execution. Tasks can be submitted to the thread pool using the execute() method. For example, assuming there is a MyTask class that implements the Runnable interface, you can submit the task in the following way:

executor.execute(new MyTask());

3. Periodically execute the task

If you want the task to be executed periodically To execute, you can use the Executors.newScheduledThreadPool(int n) method to create a scheduling thread pool. Where n represents the number of threads. Then, you can use the scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) method to submit the task to the thread pool for periodic execution.

ScheduledExecutorService scheduledExecutor = Executors.newScheduledThreadPool(2);
scheduledExecutor.scheduleAtFixedRate(new MyTask(), initialDelay, period, TimeUnit.SECONDS);

In the above code, initialDelay represents the delay time for the first execution of the task (in seconds), and period represents the period of the task (in seconds).

4. Processing task results

During the execution of the task, the execution result of the task can be obtained through the Future object. The Future object represents the result of an asynchronous operation, and the return value can be obtained through the get() method. After executing the task, you can obtain the Future object through the submit() method.

Future<Integer> future = executor.submit(new MyTask(), 100);
int result = future.get();

In the above code, the submit() method can accept a Callable object as a parameter and return a Future object. By calling the get() method, you can obtain the execution result of the Callable task.

5. Close the thread pool

When the thread pool is no longer needed, it should be closed to release resources. You can use the shutdown() method to shut down the thread pool. The thread pool will continue to execute the task until the task is completed.

executor.shutdown();

In addition, you can also use the shutdownNow() method to shut down the thread pool. However, this method attempts to interrupt all executing tasks and returns a list of unexecuted tasks.

executor.shutdownNow();

In summary, the Executor framework can easily implement a thread pool and implement periodic execution of tasks and result processing. In Java 7, using thread pools can improve the performance and efficiency of multi-threaded programs. I hope this article will help you use thread pools in Java to implement periodic execution of tasks and result processing.

Reference source:

• Oracle official documentation: https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ExecutorService.html

The above is the detailed content of How to use thread pool in Java 7 to implement periodic execution of tasks and result processing. For more information, please follow other related articles on the PHP Chinese website!