Cancellable.java

package com.koushikdutta.async.future;

public interface Cancellable {
    /**
     * Check whether this asynchronous operation completed successfully.
     * @return
     */
    boolean isDone();

    /**
     * Check whether this asynchronous operation has been cancelled.
     * @return
     */
    boolean isCancelled();

    /**
     * Attempt to cancel this asynchronous operation.
     * @return The return value is whether the operation cancelled successfully.
     */
    boolean cancel();
}