Package net.dv8tion.jda.api.utils

Class Result<T>

java.lang.Object
net.dv8tion.jda.api.utils.Result<T>
Type Parameters:
T - The success type
public class Result<T> extends Object
Represents a computation or task result.
This result may be a failure or success.

This is a value type and does not implement Object.equals(Object) or Object.hashCode()!

Since:
4.2.1

  • Method Details

    • success

      @Nonnull @CheckReturnValue public static <E> Result<E> success(@Nullable E value)
      Creates a successful result.
      Type Parameters:
      E - The success type
      Parameters:
      value - The success value
      Returns:
      Result

    • failure

      @Nonnull @CheckReturnValue public static <E> Result<E> failure(@Nonnull Throwable error)
      Creates a failure result.
      Type Parameters:
      E - The success type
      Parameters:
      error - The failure throwable
      Returns:
      Result
      Throws:
      IllegalArgumentException - If the provided error is null

    • defer

      @Nonnull @CheckReturnValue public static <E> Result<E> defer(@Nonnull Supplier<? extends E> supplier)
      Creates a result instance from the provided supplier.
      If the supplier throws an exception, a failure result is returned.
      Type Parameters:
      E - The success type
      Parameters:
      supplier - The supplier
      Returns:
      Result instance with the supplied value or exception failure
      Throws:
      IllegalArgumentException - If the supplier is null

    • isFailure

      public boolean isFailure()
      True if this result is a failure.
      Use getFailure() or expect(Predicate) to handle failures.
      Returns:
      True, if this is a failure result

    • isSuccess

      public boolean isSuccess()
      True if this result is a success.
      Use get() or map(Function) to handle success values.
      Returns:
      True, if this is a successful result

    • onFailure

      @Nonnull public Result<T> onFailure(@Nonnull Consumer<? super Throwable> callback)
      Passive error handler.
      This will apply the provided callback if isFailure() is true and return the same result for further chaining.
      Parameters:
      callback - The passive callback
      Returns:
      The same result instance
      Throws:
      IllegalArgumentException - If the callback is null

    • onSuccess

      @Nonnull public Result<T> onSuccess(@Nonnull Consumer<? super T> callback)
      Passive success handler.
      This will apply the provided callback if isSuccess() is true and return the same result for further chaining.
      Parameters:
      callback - The passive callback
      Returns:
      The same result instance
      Throws:
      IllegalArgumentException - If the callback is null

    • map

      @Nonnull @CheckReturnValue public <U> Result<U> map(@Nonnull Function<? super T,? extends U> function)
      Composite function to convert a result value to another value.
      This will only apply the function is isSuccess() is true.
      Type Parameters:
      U - The result type
      Parameters:
      function - The conversion function
      Returns:
      The mapped result
      Throws:
      IllegalArgumentException - If the provided function is null
      See Also:

    • flatMap

      @Nonnull @CheckReturnValue public <U> Result<U> flatMap(@Nonnull Function<? super T,? extends Result<U>> function)
      Composite function to convert a result value to another result.
      This will only apply the function is isSuccess() is true.
      Type Parameters:
      U - The result type
      Parameters:
      function - The conversion function
      Returns:
      The mapped result
      Throws:
      IllegalArgumentException - If the provided function is null

    • get

      @UnknownNullability public T get()
      Unwraps the success value of this result.
      This only works if isSuccess() is true and throws otherwise.
      Returns:
      The result value
      Throws:
      IllegalStateException - If the result is not successful

    • getFailure

      @Nullable public Throwable getFailure()
      Unwraps the error for this result.
      This will be null if isFailure() is false.
      Returns:
      The error or null

    • expect

      @Nonnull public Result<T> expect(@Nonnull Predicate<? super Throwable> predicate)
      Throws the wrapped exception if the provided predicate returns true.
      This will never provide a null error to the predicate. A successful result will never throw.
      Parameters:
      predicate - The test predicate
      Returns:
      The same result instance
      Throws:
      IllegalArgumentException - If the provided predicate is null
      IllegalStateException - If the predicate returns true, the cause will be the wrapped exception

    • toString

      public String toString()
      Overrides:
      toString in class Object