org.apache.commons.lang.exception
Interface Nestable

All Known Implementing Classes:
NestableError, NestableException, NestableRuntimeException, NotImplementedException

public interface Nestable

An interface to be implemented by Throwable extensions which would like to be able to nest root exceptions inside themselves.

Since:
1.0
Version:
$Id: Nestable.java 512889 2007-02-28 18:18:20Z dlr $
Author:
Daniel L. Rall, Kasper Nielsen, Steven Caswell, Pete Gieser

Method Summary
 java.lang.Throwable getCause()
          Returns the reference to the exception or error that caused the exception implementing the Nestable to be thrown.
 java.lang.String getMessage()
          Returns the error message of this and any nested Throwable.
 java.lang.String getMessage(int index)
          Returns the error message of the Throwable in the chain of Throwables at the specified index, numbered from 0.
 java.lang.String[] getMessages()
          Returns the error message of this and any nested Throwables in an array of Strings, one element for each message.
 java.lang.Throwable getThrowable(int index)
          Returns the Throwable in the chain of Throwables at the specified index, numbered from 0.
 int getThrowableCount()
          Returns the number of nested Throwables represented by this Nestable, including this Nestable.
 java.lang.Throwable[] getThrowables()
          Returns this Nestable and any nested Throwables in an array of Throwables, one element for each Throwable.
 int indexOfThrowable(java.lang.Class type)
          Returns the index, numbered from 0, of the first occurrence of the specified type, or a subclass, in the chain of Throwables.
 int indexOfThrowable(java.lang.Class type, int fromIndex)
          Returns the index, numbered from 0, of the first Throwable that matches the specified type, or a subclass, in the chain of Throwables with an index greater than or equal to the specified index.
 void printPartialStackTrace(java.io.PrintWriter out)
          Prints the stack trace for this exception only--root cause not included--using the provided writer.
 void printStackTrace(java.io.PrintStream out)
          Prints the stack trace of this exception to the specified print stream.
 void printStackTrace(java.io.PrintWriter out)
          Prints the stack trace of this exception to the specified print writer.
 

Method Detail

getCause

public java.lang.Throwable getCause()
Returns the reference to the exception or error that caused the exception implementing the Nestable to be thrown.

Returns:
throwable that caused the original exception

getMessage

public java.lang.String getMessage()
Returns the error message of this and any nested Throwable.

Returns:
the error message

getMessage

public java.lang.String getMessage(int index)
Returns the error message of the Throwable in the chain of Throwables at the specified index, numbered from 0.

Parameters:
index - the index of the Throwable in the chain of Throwables
Returns:
the error message, or null if the Throwable at the specified index in the chain does not contain a message
Throws:
java.lang.IndexOutOfBoundsException - if the index argument is negative or not less than the count of Throwables in the chain

getMessages

public java.lang.String[] getMessages()
Returns the error message of this and any nested Throwables in an array of Strings, one element for each message. Any Throwable not containing a message is represented in the array by a null. This has the effect of cause the length of the returned array to be equal to the result of the getThrowableCount() operation.

Returns:
the error messages

getThrowable

public java.lang.Throwable getThrowable(int index)
Returns the Throwable in the chain of Throwables at the specified index, numbered from 0.

Parameters:
index - the index, numbered from 0, of the Throwable in the chain of Throwables
Returns:
the Throwable
Throws:
java.lang.IndexOutOfBoundsException - if the index argument is negative or not less than the count of Throwables in the chain

getThrowableCount

public int getThrowableCount()
Returns the number of nested Throwables represented by this Nestable, including this Nestable.

Returns:
the throwable count

getThrowables

public java.lang.Throwable[] getThrowables()
Returns this Nestable and any nested Throwables in an array of Throwables, one element for each Throwable.

Returns:
the Throwables

indexOfThrowable

public int indexOfThrowable(java.lang.Class type)
Returns the index, numbered from 0, of the first occurrence of the specified type, or a subclass, in the chain of Throwables. The method returns -1 if the specified type is not found in the chain.

NOTE: From v2.1, we have clarified the Nestable interface such that this method matches subclasses. If you want to NOT match subclasses, please use ExceptionUtils.indexOfThrowable(Throwable, Class) (which is avaiable in all versions of lang).

Parameters:
type - the type to find, subclasses match, null returns -1
Returns:
index of the first occurrence of the type in the chain, or -1 if the type is not found

indexOfThrowable

public int indexOfThrowable(java.lang.Class type,
                            int fromIndex)
Returns the index, numbered from 0, of the first Throwable that matches the specified type, or a subclass, in the chain of Throwables with an index greater than or equal to the specified index. The method returns -1 if the specified type is not found in the chain.

NOTE: From v2.1, we have clarified the Nestable interface such that this method matches subclasses. If you want to NOT match subclasses, please use ExceptionUtils.indexOfThrowable(Throwable, Class, int) (which is avaiable in all versions of lang).

Parameters:
type - the type to find, subclasses match, null returns -1
fromIndex - the index, numbered from 0, of the starting position in the chain to be searched
Returns:
index of the first occurrence of the type in the chain, or -1 if the type is not found
Throws:
java.lang.IndexOutOfBoundsException - if the fromIndex argument is negative or not less than the count of Throwables in the chain

printStackTrace

public void printStackTrace(java.io.PrintWriter out)
Prints the stack trace of this exception to the specified print writer. Includes information from the exception, if any, which caused this exception.

Parameters:
out - PrintWriter to use for output.

printStackTrace

public void printStackTrace(java.io.PrintStream out)
Prints the stack trace of this exception to the specified print stream. Includes information from the exception, if any, which caused this exception.

Parameters:
out - PrintStream to use for output.

printPartialStackTrace

public void printPartialStackTrace(java.io.PrintWriter out)
Prints the stack trace for this exception only--root cause not included--using the provided writer. Used by NestableDelegate to write individual stack traces to a buffer. The implementation of this method should call super.printStackTrace(out); in most cases.

Parameters:
out - The writer to use.


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