List<LoadContext> processedContexts = new ArrayList<LoadContext>();
int index = 0;
LoadException exception = null;
while (index < futures.size()) {
try {
Future future = completionService.take();// 它也可能被打断
future.get();
} catch (InterruptedException e) {
exception = new LoadException(e);
break;
} catch (ExecutionException e) {