如果我想在后台任务中并行运行Stream,是否可以以较低的优先级运行它?如果是这样怎么办?
最佳答案
是的,有可能。
步骤如下:
ForkJoinWorkerThreadFactory
,该代码创建具有适当优先级的线程。 ForkJoinPool
。 ForkJoinPool
像这样的东西:
public class MyThread extends ForkJoinWorkerThread {
public MyThread(ForkJoinPool pool, int priority) {
super(pool);
setPriority(priority);
}
}
final int poolSize = ...
final int priority = ...
List<Long> aList = LongStream.rangeClosed(firstNum, lastNum).boxed()
.collect(Collectors.toList());
ForkJoinWorkerThreadFactory factory = new ForkJoinWorkerThreadFactory() {
public ForkJoinWorkerThread newThread(ForkJoinPool pool) {
return new MyThread(pool, priority);
}
};
/*
ForkJoinWorkerThreadFactory factory = pool -> new MyThread(
pool,
priority
);
*/
ForkJoinPool customThreadPool = new ForkJoinPool(
poolSize, factory, null, false);
long actualTotal = customThreadPool.submit(
() -> aList.parallelStream().reduce(0L, Long::sum)).get();
(示例代码改自http://www.baeldung.com/java-8-parallel-streams-custom-threadpool)