使用ParallelStream-Java[duplicate]时抛出InterruptedException

Question

我有一个嵌套for循环的方法，如下所示：

public MinSpecSetFamily getMinDomSpecSets() throws InterruptedException {
    MinSpecSetFamily result = new MinSpecSetFamily();
    ResourceType minRT = this.getFirstEssentialResourceType();
    if (minRT == null || minRT.noSpecies()) {
        System.out.println("There is something wrong with the "
                + "minimal rticator, such as adjacent to no species. ");
    }
    for (Species spec : minRT.specList) {
        ArrayList<SpecTreeNode> leafList = this.getMinimalConstSpecTreeRootedAt(spec).getLeaves();
        for (SpecTreeNode leaf : leafList) {
            result.addSpecSet(new SpecSet(leaf.getAncestors()));
        }
    }
    return result;
}

public MinSpecSetFamily getMinDomSpecSets() throws InterruptedException {
    ResourceType minRT = this.getFirstEssentialResourceType();
    if (minRT == null || minRT.noSpecies()) {
        System.out.println("There is something wrong with the "
                + "minimal rticator, such as adjacent to no species. ");
    }

    MinSpecSetFamily result = minRT.specList.parallelStream()
            .flatMap(spec -> getMinimalConstSpecTreeRootedAt(spec).getLeaves().parallelStream())
            .map(leaf -> new SpecSet(leaf.getAncestors()))
            .collect(MinSpecSetFamily::new, MinSpecSetFamily::addSpecSet, MinSpecSetFamily::addMSSF);
    return result;
}

在我想在'get leaves()'方法中引入interruptedexception之前，这一直很正常。现在，ParallelStream版本将不会编译，因为它说我有一个未报告的InterruptedException，必须捕获或声明要抛出该InterruptedException。我认为这是因为ParallelStream在多个线程上运行。IDE建议的try/catch块组合不能解决此问题。

在Interrupt parallel Stream execution中发布的第二个解决方案表明，我可能可以使用forkjoinpool解决这个问题，但我无法找到如何修改我的方法以使用这种方法。

Answer 1

如果您想要坚持您当前的设计，您只需要捕捉到异常：

.flatMap(spec -> {
     try {
       return getMinimalConstSpecTreeRootedAt(spec).getLeaves().parallelStream();
     } catch (InterruptedException e) {
       // return something else to indicate interruption
       // maybe an empty stream?
     }
 }).map(...)

注意，并行流的并行流可能是不必要的，并且仅对顶层流进行并行化可能在性能方面是足够的。