我有以下方法：
public String getResult() {
List<String> serversList = getServerListFromDB();
List<String> appList = getAppListFromDB();
List<String> userList = getUserFromDB();
return getResult(serversList,appList,userList);
}
在这里,我按顺序调用三个方法,然后点击DB并获取结果,然后我对从DB命中获得的结果进行后处理.我知道如何通过使用Threads同时调用这三种方法.但我想使用Java 8 Parallel Stream来实现这一目标.有人可以指导我如何通过Parallel Streams实现同样的目标吗？
private void getInformation() {
method1();
method2();
method3();
method4();
method5();
}
解决方法
您可以通过以下方式使用CompletableFuture：
public String getResult() {
// Create Stream of tasks:
Stream<Supplier<List<String>>> tasks = Stream.of(
() -> getServerListFromDB(),() -> getAppListFromDB(),() -> getUserFromDB());
List<List<String>> lists = tasks
// Supply all the tasks for execution and collect CompletableFutures
.map(CompletableFuture::supplyAsync).collect(Collectors.toList())
// Join all the CompletableFutures to gather the results
.stream()
.map(CompletableFuture::join).collect(Collectors.toList());
// Use the results. They are guaranteed to be ordered in the same way as the tasks
return getResult(lists.get(0),lists.get(1),lists.get(2));
}
