我有一个嵌套for循环的方法如下:
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;
}
这很好用,但应用程序性能至关重要,所以我修改了方法以使用parallelStream()
,如下所示:
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;
}
这个工作正常,直到我想在'getLeaves()'方法中引入InterruptedException
。现在parallelStream
版本将无法编译,因为它说我有一个未报告的InterruptedException
必须被捕获或声明被抛出。我认为这是因为parallelStream
在多个线程上运行。我的IDE建议的try / catch块的组合不能解决问题。
Interrupt parallel Stream execution中发布的第二个解决方案
建议我可以使用ForkJoinPool
来解决问题,但我无法弄清楚如何修改我的方法来使用这种方法。
答案 0 :(得分:1)
如果你想坚持当前的设计,你只需要抓住例外:
.flatMap(spec -> {
try {
return getMinimalConstSpecTreeRootedAt(spec).getLeaves().parallelStream();
} catch (InterruptedException e) {
// return something else to indicate interruption
// maybe an empty stream?
}
}).map(...)
请注意,并行流的并行流可能是不必要的,并且仅在顶级流的并行化可能是足够的性能。