Package net.dv8tion.jda.api.utils.concurrent

Interface Task<T>

  • Type Parameters:
    T - The result type
    public interface Task<T>
    Represents an asynchronous task.
    Note: The underlying task may already be started.

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void cancel()
      Cancels the task and will emit a CancellationException.
      T get()
      Blocks the current thread until the result is ready.
      boolean isStarted()
      Whether this task has started.
      Task<T> onError​(java.util.function.Consumer<? super java.lang.Throwable> callback)
      Provide a callback for exception handling.
      Task<T> onSuccess​(java.util.function.Consumer<? super T> callback)
      Provide a callback for success handling.

    • Method Detail

      • isStarted

        boolean isStarted()
        Whether this task has started.
        Returns:
        True, if this task has already started.

      • onError

        @Nonnull
Task<T> onError​(@Nonnull
                java.util.function.Consumer<? super java.lang.Throwable> callback)
        Provide a callback for exception handling.
        This is an asynchronous operation.

        The error will be logged regardless of your callback, this only exists to handle failures for other purposes.

        Parameters:
        callback - The error callback
        Returns:
        The current Task instance for chaining
        Throws:
        java.lang.IllegalArgumentException - If null is provided

      • onSuccess

        @Nonnull
Task<T> onSuccess​(@Nonnull
                  java.util.function.Consumer<? super T> callback)
        Provide a callback for success handling.
        This is an asynchronous operation.
        Parameters:
        callback - The success callback
        Returns:
        The current Task instance for chaining
        Throws:
        java.lang.IllegalArgumentException - If null is provided

      • get

        @Nonnull
T get()
        Blocks the current thread until the result is ready.
        This will not work on the default JDA event thread because it might depend on other events to be processed, which could lead to a deadlock.
        Returns:
        The result value
        Throws:
        java.lang.UnsupportedOperationException - If this is called on the default JDA event thread
        java.util.concurrent.CompletionException - If some exception occurred (such as TimeoutException).
        java.util.concurrent.CancellationException - If the request was cancelled

      • cancel

        void cancel()
        Cancels the task and will emit a CancellationException.