java 8 lambda ambiguous runnable和callback

Question

Executors.newFixedThreadPool(3).submit(() -> {doSmth();});

“模糊方法调用。在ExecutorService中提交（Callable）并在ExecutorService匹配中提交（Runnable）。”

如何解决？我知道我可以使用匿名类，但我想使用Function。

Answer 1

Executors.newFixedThreadPool(3).submit(() -> 1); //Callable
Executors.newFixedThreadPool(3).submit(() -> {doSmth();}); //Runnable

Answer 2

在含糊不清的情况下，明确提供类型：

Runnable runnable = () -> {doSmth();}
submit(runnable);
//or:
submit((Runnable) () -> {doSmth();});