提问者:小点点

让CompletableFuture异常()处理供应Async()异常


问题很简单:我正在寻找一种优雅的方式,将<code>CompletableFuture#与<code>CompletableFuture#supplySync</code>一起使用。这是不起作用的:

private void doesNotCompile() {
    CompletableFuture<String> sad = CompletableFuture
            .supplyAsync(() -> throwSomething())
            .exceptionally(Throwable::getMessage);
}

private String throwSomething() throws Exception {
    throw new Exception();
}

我认为异常()背后的想法正是为了处理抛出异常的情况。然而,如果我这样做,它会起作用:

private void compiles() {
    CompletableFuture<String> thisIsFine = CompletableFuture.supplyAsync(() -> {
        try {
            throwSomething();
            return "";
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }).exceptionally(Throwable::getMessage);
}

我可以这样做,但是这看起来很可怕,而且让事情更难维护。有没有一种不需要将所有< code>Exception转换为< code>RuntimeException的方法来保持这种简洁?


共1个答案

匿名用户

这可能不是一个超级受欢迎的库,但我们使用它(有时我也在那里工作;次要的)内部:没有例外。它真的,真的很适合我的口味。这不是它唯一拥有的东西,但肯定涵盖了您的使用案例:

以下是一个示例:

import com.machinezoo.noexception.Exceptions;
import java.util.concurrent.CompletableFuture;

public class SO64937499 {

    public static void main(String[] args) {
        CompletableFuture<String> sad = CompletableFuture
            .supplyAsync(Exceptions.sneak().supplier(SO64937499::throwSomething))
            .exceptionally(Throwable::getMessage);
    }

    private static String throwSomething() throws Exception {
        throw new Exception();
    }
}

或者,您可以自己创建这些:

final class CheckedSupplier<T> implements Supplier<T> {

    private final SupplierThatThrows<T> supplier;

    CheckedSupplier(SupplierThatThrows<T> supplier) {
        this.supplier = supplier;
    }

    @Override
    public T get() {
        try {
            return supplier.get();
        } catch (Throwable exception) {
            throw new RuntimeException(exception);
        }
    }
}



@FunctionalInterface
interface SupplierThatThrows<T> {

    T get() throws Throwable;
}

和用法:

 CompletableFuture<String> sad = CompletableFuture
        .supplyAsync(new CheckedSupplier<>(SO64937499::throwSomething))
        .exceptionally(Throwable::getMessage);