org.apache.commons.lang.exception
クラス ExceptionUtils

java.lang.Object
  org.apache.commons.lang.exception.ExceptionUtils

public class ExceptionUtils

extends Object

Provides utilities for manipulating and examining Throwable objects.

導入されたバージョン:

1.0

バージョン:

$Id: ExceptionUtils.java,v 1.1.1.1 2004/02/13 10:02:05 hioki Exp $

作成者:

Daniel Rall, Dmitri Plotnikov, Stephen Colebourne, Gary Gregory, Pete Gieser

コンストラクタの概要

ExceptionUtils()
Public constructor allows an instance of ExceptionUtils to be created, although that is not normally necessary.

メソッドの概要

static void	addCauseMethodName(String methodName) Adds to the list of method names used in the search for Throwable objects.
static Throwable	getCause(Throwable throwable) Introspects the Throwable to obtain the cause.
static Throwable	getCause(Throwable throwable, String[] methodNames) Introspects the Throwable to obtain the cause.
static String	getFullStackTrace(Throwable throwable) A way to get the entire nested stack-trace of an throwable.
static Throwable	getRootCause(Throwable throwable) Introspects the Throwable to obtain the root cause.
static String[]	getRootCauseStackTrace(Throwable throwable) Creates a compact stack trace for the root cause of the supplied Throwable.
static String[]	getStackFrames(Throwable throwable) Captures the stack trace associated with the specified Throwable object, decomposing it into a list of stack frames.
static String	getStackTrace(Throwable throwable) Gets the stack trace from a Throwable as a String.
static int	getThrowableCount(Throwable throwable) Counts the number of Throwable objects in the exception chain.
static Throwable[]	getThrowables(Throwable throwable) Returns the list of Throwable objects in the exception chain.
static int	indexOfThrowable(Throwable throwable, Class type) Returns the (zero based) index of the first Throwable that matches the specified type in the exception chain.
static int	indexOfThrowable(Throwable throwable, Class type, int fromIndex) Returns the (zero based) index of the first Throwable that matches the specified type in the exception chain from a specified index.
static boolean	isNestedThrowable(Throwable throwable) Checks whether this Throwable class can store a cause.
static boolean	isThrowableNested() Checks if the Throwable class has a getCause method.
static void	printRootCauseStackTrace(Throwable throwable) Prints a compact stack trace for the root cause of a throwable to System.err.
static void	printRootCauseStackTrace(Throwable throwable, PrintStream stream) Prints a compact stack trace for the root cause of a throwable.
static void	printRootCauseStackTrace(Throwable throwable, PrintWriter writer) Prints a compact stack trace for the root cause of a throwable.
static void	removeCommonFrames(List causeFrames, List wrapperFrames) Removes common frames from the cause trace given the two stack traces.

クラス java.lang.Object から継承したメソッド

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

コンストラクタの詳細

ExceptionUtils

public ExceptionUtils()

Public constructor allows an instance of ExceptionUtils to be created, although that is not normally necessary.

メソッドの詳細

addCauseMethodName

public static void addCauseMethodName(String methodName)

Adds to the list of method names used in the search for Throwable objects.

パラメータ:

methodName - the methodName to add to the list, null and empty strings are ignored

導入されたバージョン:

2.0

getCause

public static Throwable getCause(Throwable throwable)

Introspects the Throwable to obtain the cause.

The method searches for methods with specific names that return a Throwable object. This will pick up most wrapping exceptions, including those from JDK 1.4, and NestableException. The method names can be added to using addCauseMethodName(String).

The default list searched for are:

• getCause()
• getNextException()
• getTargetException()
• getException()
• getSourceException()
• getRootCause()
• getCausedByException()
• getNested()

In the absence of any such method, the object is inspected for a detail field assignable to a Throwable.

If none of the above is found, returns null.

パラメータ:

throwable - the throwable to introspect for a cause, may be null

戻り値:

the cause of the Throwable, null if none found or null throwable input

getCause

public static Throwable getCause(Throwable throwable,
                                 String[] methodNames)

Introspects the Throwable to obtain the cause.

1. Try known exception types.
2. Try the supplied array of method names.
3. Try the field 'detail'.

A null set of method names means use the default set. A null in the set of method names will be ignored.

パラメータ:

throwable - the throwable to introspect for a cause, may be null

methodNames - the method names, null treated as default set

戻り値:

the cause of the Throwable, null if none found or null throwable input

getRootCause

public static Throwable getRootCause(Throwable throwable)

Introspects the Throwable to obtain the root cause.

This method walks through the exception chain to the last element, "root" of the tree, using getCause(Throwable), and returns that exception.

パラメータ:

throwable - the throwable to get the root cause for, may be null

戻り値:

the root cause of the Throwable, null if none found or null throwable input

isThrowableNested

public static boolean isThrowableNested()

Checks if the Throwable class has a getCause method.

This is true for JDK 1.4 and above.

戻り値:

true if Throwable is nestable

導入されたバージョン:

2.0

isNestedThrowable

public static boolean isNestedThrowable(Throwable throwable)

Checks whether this Throwable class can store a cause.

This method does not check whether it actually does store a cause.

パラメータ:

throwable - the Throwable to examine, may be null

戻り値:

boolean true if nested otherwise false

導入されたバージョン:

2.0

getThrowableCount

public static int getThrowableCount(Throwable throwable)

Counts the number of Throwable objects in the exception chain.

A throwable without cause will return 1. A throwable with one cause will return 2 and so on. A null throwable will return 0.

パラメータ:

throwable - the throwable to inspect, may be null

戻り値:

the count of throwables, zero if null input

getThrowables

public static Throwable[] getThrowables(Throwable throwable)

Returns the list of Throwable objects in the exception chain.

A throwable without cause will return an array containing one element - the input throwable. A throwable with one cause will return an array containing two elements. - the input throwable and the cause throwable. A null throwable will return an array size zero.

パラメータ:

throwable - the throwable to inspect, may be null

戻り値:

the array of throwables, never null

indexOfThrowable

public static int indexOfThrowable(Throwable throwable,
                                   Class type)

Returns the (zero based) index of the first Throwable that matches the specified type in the exception chain.

A null throwable returns -1. A null type returns -1. No match in the chain returns -1.

パラメータ:

throwable - the throwable to inspect, may be null

type - the type to search for

戻り値:

the index into the throwable chain, -1 if no match or null input

indexOfThrowable

public static int indexOfThrowable(Throwable throwable,
                                   Class type,
                                   int fromIndex)

Returns the (zero based) index of the first Throwable that matches the specified type in the exception chain from a specified index.

A null throwable returns -1. A null type returns -1. No match in the chain returns -1. A negative start index is treated as zero. A start index greater than the number of throwables returns -1.

パラメータ:

throwable - the throwable to inspect, may be null

type - the type to search for

fromIndex - the (zero based) index of the starting position, negative treated as zero, larger than chain size returns -1

戻り値:

the index into the throwable chain, -1 if no match or null input

printRootCauseStackTrace

public static void printRootCauseStackTrace(Throwable throwable)

Prints a compact stack trace for the root cause of a throwable to System.err.

The compact stack trace starts with the root cause and prints stack frames up to the place where it was caught and wrapped. Then it prints the wrapped exception and continues with stack frames until the wrapper exception is caught and wrapped again, etc.

The method is equivalent to printStackTrace for throwables that don't have nested causes.

パラメータ:

throwable - the throwable to output

導入されたバージョン:

2.0

printRootCauseStackTrace

public static void printRootCauseStackTrace(Throwable throwable,
                                            PrintStream stream)

Prints a compact stack trace for the root cause of a throwable.

The compact stack trace starts with the root cause and prints stack frames up to the place where it was caught and wrapped. Then it prints the wrapped exception and continues with stack frames until the wrapper exception is caught and wrapped again, etc.

The method is equivalent to printStackTrace for throwables that don't have nested causes.

パラメータ:

throwable - the throwable to output, may be null

stream - the stream to output to, may not be null

例外:

IllegalArgumentException - if the stream is null

導入されたバージョン:

2.0

printRootCauseStackTrace

public static void printRootCauseStackTrace(Throwable throwable,
                                            PrintWriter writer)

Prints a compact stack trace for the root cause of a throwable.

The compact stack trace starts with the root cause and prints stack frames up to the place where it was caught and wrapped. Then it prints the wrapped exception and continues with stack frames until the wrapper exception is caught and wrapped again, etc.

The method is equivalent to printStackTrace for throwables that don't have nested causes.

パラメータ:

throwable - the throwable to output, may be null

writer - the writer to output to, may not be null

例外:

IllegalArgumentException - if the writer is null

導入されたバージョン:

2.0

getRootCauseStackTrace

public static String[] getRootCauseStackTrace(Throwable throwable)

Creates a compact stack trace for the root cause of the supplied Throwable.

パラメータ:

throwable - the throwable to examine, may be null

戻り値:

an array of stack trace frames, never null

導入されたバージョン:

2.0

removeCommonFrames

public static void removeCommonFrames(List causeFrames,
                                      List wrapperFrames)

Removes common frames from the cause trace given the two stack traces.

パラメータ:

causeFrames - stack trace of a cause throwable

wrapperFrames - stack trace of a wrapper throwable

例外:

IllegalArgumentException - if either argument is null

導入されたバージョン:

2.0

getStackTrace

public static String getStackTrace(Throwable throwable)

Gets the stack trace from a Throwable as a String.

パラメータ:

throwable - the Throwable to be examined

戻り値:

the stack trace as generated by the exception's printStackTrace(PrintWriter) method

getFullStackTrace

public static String getFullStackTrace(Throwable throwable)

A way to get the entire nested stack-trace of an throwable.

パラメータ:

throwable - the Throwable to be examined

戻り値:

the nested stack trace, with the root cause first

導入されたバージョン:

2.0

getStackFrames

public static String[] getStackFrames(Throwable throwable)

Captures the stack trace associated with the specified Throwable object, decomposing it into a list of stack frames.

パラメータ:

throwable - the Throwable to exaamine, may be null

戻り値:

an array of strings describing each stack frame, never null