Package org.apache.tapestry5.commons.util

## Class ExceptionUtils

- java.lang.Object
- - org.apache.tapestry5.commons.util.ExceptionUtils

-     public class ExceptionUtils
      extends Object

  Contains static methods useful for manipulating exceptions.

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `ExceptionUtils()` |

  - ### Method Summary

    All Methods Static Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `static <T extends Throwable> T` | `findCause​(Throwable t, Class<T> type)` | Locates a particular type of exception, working its way via the cause property of each exception in the exception stack.
    `static <T extends Throwable> T` | `findCause​(Throwable t, Class<T> type, PropertyAccess access)` | Locates a particular type of exception, working its way down via any property that returns some type of Exception.
    `static String` | `toMessage​(Throwable exception)` | Extracts the message from an exception.

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

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

- - ### Constructor Detail

    - #### ExceptionUtils

          public ExceptionUtils()

  - ### Method Detail

    - #### findCause

          public static <T extends Throwable> T findCause​(Throwable t,
                                                          Class<T> type)

      Locates a particular type of exception, working its way via the cause property of each exception in the exception stack.
      Parameters:
        `t` - the outermost exception
        `type` - the type of exception to search for
      Returns:
        the first exception of the given type, if found, or null

    - #### findCause

          public static <T extends Throwable> T findCause​(Throwable t,
                                                          Class<T> type,
                                                          PropertyAccess access)

      Locates a particular type of exception, working its way down via any property that returns some type of Exception. This is more expensive, but more accurate, than `findCause(Throwable, Class)` as it works with older exceptions that do not properly implement the (relatively new) cause property.
      Parameters:
        `t` - the outermost exception
        `type` - the type of exception to search for
        `access` - used to access properties
      Returns:
        the first exception of the given type, if found, or null

    - #### toMessage

          public static String toMessage​(Throwable exception)

      Extracts the message from an exception. If the exception's message is null, returns the exceptions class name.
      Parameters:
        `exception` - to extract message from
      Returns:
        message or class name
      Since:
        5.4