org.springframework.security.web.util
Class ThrowableAnalyzer

java.lang.Object
  extended by org.springframework.security.web.util.ThrowableAnalyzer

public class ThrowableAnalyzer
extends Object

Handler for analyzing Throwable instances. Can be subclassed to customize its behavior.

Since:
2.0
Version:
$Id: ThrowableAnalyzer.java 3606 2009-04-25 07:03:15Z ltaylor $
Author:
Andreas Senft

Field Summary
static ThrowableCauseExtractor DEFAULT_EXTRACTOR
          Default extractor for Throwable instances.
static ThrowableCauseExtractor INVOCATIONTARGET_EXTRACTOR
          Default extractor for InvocationTargetException instances.
 
Constructor Summary
ThrowableAnalyzer()
          Creates a new ThrowableAnalyzer instance.
 
Method Summary
 Throwable[] determineCauseChain(Throwable throwable)
          Determines the cause chain of the provided Throwable.
 Throwable getFirstThrowableOfType(Class<? extends Throwable> throwableType, Throwable[] chain)
          Returns the first throwable from the passed in array that is assignable to the provided type.
protected  void initExtractorMap()
          Initializes associations between Throwables and ThrowableCauseExtractors.
protected  void registerExtractor(Class<? extends Throwable> throwableType, ThrowableCauseExtractor extractor)
          Registers a ThrowableCauseExtractor for the specified type.
static void verifyThrowableHierarchy(Throwable throwable, Class<? extends Throwable> expectedBaseType)
          Verifies that the provided throwable is a valid subclass of the provided type (or of the type itself).
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

DEFAULT_EXTRACTOR

public static final ThrowableCauseExtractor DEFAULT_EXTRACTOR
Default extractor for Throwable instances.

See Also:
Throwable.getCause()

INVOCATIONTARGET_EXTRACTOR

public static final ThrowableCauseExtractor INVOCATIONTARGET_EXTRACTOR
Default extractor for InvocationTargetException instances.

See Also:
InvocationTargetException.getTargetException()
Constructor Detail

ThrowableAnalyzer

public ThrowableAnalyzer()
Creates a new ThrowableAnalyzer instance.

Method Detail

registerExtractor

protected final void registerExtractor(Class<? extends Throwable> throwableType,
                                       ThrowableCauseExtractor extractor)
Registers a ThrowableCauseExtractor for the specified type. Can be used in subclasses overriding initExtractorMap().

Parameters:
throwableType - the type (has to be a subclass of Throwable)
extractor - the associated ThrowableCauseExtractor (not null)
Throws:
IllegalArgumentException - if one of the arguments is invalid

initExtractorMap

protected void initExtractorMap()
Initializes associations between Throwables and ThrowableCauseExtractors. The default implementation performs the following registrations:
  • DEFAULT_EXTRACTOR for Throwable
  • INVOCATIONTARGET_EXTRACTOR for InvocationTargetException

  • Subclasses overriding this method are encouraged to invoke the super method to perform the default registrations. They can register additional extractors as required.

    Note: An extractor registered for a specific type is applicable for that type and all subtypes thereof. However, extractors registered to more specific types are guaranteed to be resolved first. So in the default case InvocationTargetExceptions will be handled by INVOCATIONTARGET_EXTRACTOR while all other throwables are handled by DEFAULT_EXTRACTOR.

    See Also:
    registerExtractor(Class, ThrowableCauseExtractor)

    determineCauseChain

    public final Throwable[] determineCauseChain(Throwable throwable)
    Determines the cause chain of the provided Throwable. The returned array contains all throwables extracted from the stacktrace, using the registered extractors. The elements of the array are ordered: The first element is the passed in throwable itself. The following elements appear in their order downward the stacktrace.

    Note: If no ThrowableCauseExtractor is registered for this instance then the returned array will always only contain the passed in throwable.

    Parameters:
    throwable - the Throwable to analyze
    Returns:
    an array of all determined throwables from the stacktrace
    Throws:
    IllegalArgumentException - if the throwable is null
    See Also:
    initExtractorMap()

    getFirstThrowableOfType

    public final Throwable getFirstThrowableOfType(Class<? extends Throwable> throwableType,
                                                   Throwable[] chain)
    Returns the first throwable from the passed in array that is assignable to the provided type. A returned instance is safe to be cast to the specified type.

    If the passed in array is null or empty this method returns null.

    Parameters:
    throwableType - the type to look for
    chain - the array (will be processed in element order)
    Returns:
    the found Throwable, null if not found
    Throws:
    IllegalArgumentException - if the provided type is null or no subclass of Throwable

    verifyThrowableHierarchy

    public static final void verifyThrowableHierarchy(Throwable throwable,
                                                      Class<? extends Throwable> expectedBaseType)
    Verifies that the provided throwable is a valid subclass of the provided type (or of the type itself). If expectdBaseType is null, no check will be performed.

    Can be used for verification purposes in implementations of extractors.

    Parameters:
    throwable - the Throwable to check
    expectedBaseType - the type to check against
    Throws:
    IllegalArgumentException - if throwable is either null or its type is not assignable to expectedBaseType


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