# Class CompletionException

java.lang.Object
java.lang.Throwable
java.lang.Exception
java.lang.RuntimeException
java.util.concurrent.CompletionException

All Implemented Interfaces:
  `Serializable`

public class CompletionException extends RuntimeException
Exception thrown when an error or other exception is encountered in the course of completing a result or task.

Since:
  1.8
See Also:
  - Serialized Form

- ## Constructor Summary

  Constructors
  Modifier
  Constructor
  Description
  `protected`
  `CompletionException()`
  Constructs a `CompletionException` with no detail message.
  `protected`
  `CompletionException(String message)`
  Constructs a `CompletionException` with the specified detail message.
  ``
  `CompletionException(String message, Throwable cause)`
  Constructs a `CompletionException` with the specified detail message and cause.
  ``
  `CompletionException(Throwable cause)`
  Constructs a `CompletionException` with the specified cause.

- ## Method Summary

  ### Methods declared in class Throwable

  `addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString`

  ### Methods declared in class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- ## Constructor Details

  - ### CompletionException

    protected CompletionException()
    Constructs a `CompletionException` with no detail message. The cause is not initialized, and may subsequently be initialized by a call to `initCause`.

  - ### CompletionException

    protected CompletionException(String message)
    Constructs a `CompletionException` with the specified detail message. The cause is not initialized, and may subsequently be initialized by a call to `initCause`.
    Parameters:
      `message` - the detail message

  - ### CompletionException

    public CompletionException(String message, Throwable cause)
    Constructs a `CompletionException` with the specified detail message and cause.
    Parameters:
      `message` - the detail message
      `cause` - the cause (which is saved for later retrieval by the `Throwable.getCause()` method)

  - ### CompletionException

    public CompletionException(Throwable cause)
    Constructs a `CompletionException` with the specified cause. The detail message is set to `(cause == null ? null : cause.toString())` (which typically contains the class and detail message of `cause`).
    Parameters:
      `cause` - the cause (which is saved for later retrieval by the `Throwable.getCause()` method)