Fork/join
并行执行任务的框架，将任务拆成若干子任务，汇总每个子任务计算的结果。
代码语言：javascript复制public class SumTask extends RecursiveTask<Long> {
private int start;
private int end;
private int[] arr;
private int threshold = 5;
public SumTask(int start, int end, int[] arr) {
this.start = start;
this.end = end;
this.arr = arr;
}
@Override
protected Long compute() {
if(end - start > threshold) {
int mid = (start end) / 2;
SumTask subTask1 = new SumTask(start, mid, arr);
SumTask subTask2 = new SumTask(mid, end, arr);
invokeAll(subTask1, subTask2); //fork
long subResult1 = subTask1.join();
long subResult2 = subTask2.join();
System.out.println(String.format("compute %d~%d = %d", start, end, subResult1 subResult2));
return subResult1 subResult2;
} else {
long sum = 0;
for(int i = start; i < end; i ) {
sum = arr[i];
}
System.out.println(String.format("compute %d~%d = %d", start, end, sum));
return sum;
}
}
public static void main(String[] args) {
int[] arr = new int[100];
for(int i = 0; i < 100; i ) {
arr[i] = i;
}
ForkJoinPool pool = new ForkJoinPool(4);//最大并发数
ForkJoinTask<Long> task = new SumTask(0, 100, arr);
System.out.println("result:" pool.invoke(task));
}
}
