org.springframework.security.web.util
Class ThrowableAnalyzer

java.lang.Object
  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