我想创建一个CompletableFuture
已经异常完成的。
Scala 通过工厂方法提供了我正在寻找的东西:
Future.failed(new RuntimeException("No Future!"))
Java 10 或更高版本中是否有类似的东西?
我想创建一个CompletableFuture
已经异常完成的。
Scala 通过工厂方法提供了我正在寻找的东西:
Future.failed(new RuntimeException("No Future!"))
Java 10 或更高版本中是否有类似的东西?
我在 Java 8 的标准库中找不到失败的未来的工厂方法(Java 9 修复了这个问题,正如Sotirios Delimanolis指出的那样),但创建一个很容易:
/**
* Creates a {@link CompletableFuture} that has already completed
* exceptionally with the given {@code error}.
*
* @param error the returned {@link CompletableFuture} should immediately
* complete with this {@link Throwable}
* @param <R> the type of value inside the {@link CompletableFuture}
* @return a {@link CompletableFuture} that has already completed with the
* given {@code error}
*/
public static <R> CompletableFuture<R> failed(Throwable error) {
CompletableFuture<R> future = new CompletableFuture<>();
future.completeExceptionally(error);
return future;
}
Java 9 提供CompletableFuture#failedFuture(Throwable)
了
返回一个新
CompletableFuture
的,它已经在给定的异常情况下异常完成。
这或多或少是你提交的
/**
* Returns a new CompletableFuture that is already completed
* exceptionally with the given exception.
*
* @param ex the exception
* @param <U> the type of the value
* @return the exceptionally completed CompletableFuture
* @since 9
*/
public static <U> CompletableFuture<U> failedFuture(Throwable ex) {
if (ex == null) throw new NullPointerException();
return new CompletableFuture<U>(new AltResult(ex));
}