CompletionException (Java Platform SE 8 )
Keywords: java.util.concurrent.CompletionException class
Date: 2026-01-21

compact1, compact2, compact3
java.util.concurrent

## 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 and 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 inherited from class java.lang.Throwable

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

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### 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)

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