org.apache.xml.utils
Class ListingErrorHandler

java.lang.Object
  |
  +--org.apache.xml.utils.ListingErrorHandler

public class ListingErrorHandler
extends java.lang.Object
implements ErrorHandler, ErrorListener

Sample implementation of similar SAX ErrorHandler and JAXP ErrorListener.

This implementation is suitable for various use cases, and provides some basic configuration API's as well to control when we re-throw errors, etc.

Usage:

Constructor Summary
ListingErrorHandler()
          Constructor ListingErrorHandler; uses System.err.
ListingErrorHandler(java.io.PrintWriter pw)
          Constructor ListingErrorHandler; user-supplied PrintWriter.
 
Method Summary
 void error(SAXParseException exception)
          Receive notification of a recoverable error.
 void error(TransformerException exception)
          Receive notification of a recoverable error.
 void fatalError(SAXParseException exception)
          Receive notification of a non-recoverable error.
 void fatalError(TransformerException exception)
          Receive notification of a non-recoverable error.
 boolean getThrowOnError()
          User-settable behavior: when to re-throw exceptions.
 boolean getThrowOnFatalError()
          User-settable behavior: when to re-throw exceptions.
 boolean getThrowOnWarning()
          User-settable behavior: when to re-throw exceptions.
static void logExceptionLocation(java.io.PrintWriter pw, java.lang.Throwable exception)
          Print out location information about the exception.
static void logSourceLine(java.io.PrintWriter pw, SourceLocator locator)
          Print out the specific source line that caused the exception, if possible to load it.
 void setThrowOnError(boolean b)
          User-settable behavior: when to re-throw exceptions.
 void setThrowOnFatalError(boolean b)
          User-settable behavior: when to re-throw exceptions.
 void setThrowOnWarning(boolean b)
          User-settable behavior: when to re-throw exceptions.
 void warning(SAXParseException exception)
          Receive notification of a warning.
 void warning(TransformerException exception)
          Receive notification of a warning.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ListingErrorHandler

public ListingErrorHandler(java.io.PrintWriter pw)
Constructor ListingErrorHandler; user-supplied PrintWriter.

ListingErrorHandler

public ListingErrorHandler()
Constructor ListingErrorHandler; uses System.err.
Method Detail

warning

public void warning(SAXParseException exception)
             throws SAXException
Receive notification of a warning.

SAX parsers will use this method to report conditions that are not errors or fatal errors as defined by the XML 1.0 recommendation. The default behaviour is to take no action.

The SAX parser must continue to provide normal parsing events after invoking this method: it should still be possible for the application to process the document through to the end.

Filters may use this method to report other, non-XML warnings as well.

Specified by:
warning in interface ErrorHandler
Parameters:
exception - The warning information encapsulated in a SAX parse exception.
Throws:
SAXException - Any SAX exception, possibly wrapping another exception; only if setThrowOnWarning is true.
See Also:
SAXParseException

error

public void error(SAXParseException exception)
           throws SAXException
Receive notification of a recoverable error.

This corresponds to the definition of "error" in section 1.2 of the W3C XML 1.0 Recommendation. For example, a validating parser would use this callback to report the violation of a validity constraint. The default behaviour is to take no action.

The SAX parser must continue to provide normal parsing events after invoking this method: it should still be possible for the application to process the document through to the end. If the application cannot do so, then the parser should report a fatal error even if the XML 1.0 recommendation does not require it to do so.

Filters may use this method to report other, non-XML errors as well.

Specified by:
error in interface ErrorHandler
Parameters:
exception - The error information encapsulated in a SAX parse exception.
Throws:
SAXException - Any SAX exception, possibly wrapping another exception; only if setThrowOnErroris true.
See Also:
SAXParseException

fatalError

public void fatalError(SAXParseException exception)
                throws SAXException
Receive notification of a non-recoverable error.

This corresponds to the definition of "fatal error" in section 1.2 of the W3C XML 1.0 Recommendation. For example, a parser would use this callback to report the violation of a well-formedness constraint.

The application must assume that the document is unusable after the parser has invoked this method, and should continue (if at all) only for the sake of collecting addition error messages: in fact, SAX parsers are free to stop reporting any other events once this method has been invoked.

Specified by:
fatalError in interface ErrorHandler
Parameters:
exception - The error information encapsulated in a SAX parse exception.
Throws:
SAXException - Any SAX exception, possibly wrapping another exception; only if setThrowOnFatalError is true.
See Also:
SAXParseException

warning

public void warning(TransformerException exception)
             throws TransformerException
Receive notification of a warning.

Transformer can use this method to report conditions that are not errors or fatal errors. The default behaviour is to take no action.

After invoking this method, the Transformer must continue with the transformation. It should still be possible for the application to process the document through to the end.

Specified by:
warning in interface ErrorListener
Parameters:
exception - The warning information encapsulated in a transformer exception.
Throws:
TransformerException - only if setThrowOnWarning is true.
See Also:
TransformerException

error

public void error(TransformerException exception)
           throws TransformerException
Receive notification of a recoverable error.

The transformer must continue to try and provide normal transformation after invoking this method. It should still be possible for the application to process the document through to the end if no other errors are encountered.

Specified by:
error in interface ErrorListener
Parameters:
exception - The error information encapsulated in a transformer exception.
Throws:
TransformerException - only if setThrowOnError is true.
See Also:
TransformerException

fatalError

public void fatalError(TransformerException exception)
                throws TransformerException
Receive notification of a non-recoverable error.

The transformer must continue to try and provide normal transformation after invoking this method. It should still be possible for the application to process the document through to the end if no other errors are encountered, but there is no guarantee that the output will be useable.

Specified by:
fatalError in interface ErrorListener
Parameters:
exception - The error information encapsulated in a transformer exception.
Throws:
TransformerException - only if setThrowOnError is true.
See Also:
TransformerException

logExceptionLocation

public static void logExceptionLocation(java.io.PrintWriter pw,
                                        java.lang.Throwable exception)
Print out location information about the exception. Cribbed from DefaultErrorHandler.printLocation()
Parameters:
pw - PrintWriter to send output to
exception - TransformerException or SAXParseException to log information about

logSourceLine

public static void logSourceLine(java.io.PrintWriter pw,
                                 SourceLocator locator)
Print out the specific source line that caused the exception, if possible to load it.
Parameters:
pw - PrintWriter to send output to
locator - Xalan wrapper for either a JAXP or a SAX source location object

setThrowOnWarning

public void setThrowOnWarning(boolean b)
User-settable behavior: when to re-throw exceptions.

This allows per-instance configuration of ListingErrorHandlers. You can ask us to either throw an exception when we're called for various warning / error / fatalErrors, or simply log them and continue.

Parameters:
b - if we should throw an exception on warnings

getThrowOnWarning

public boolean getThrowOnWarning()
User-settable behavior: when to re-throw exceptions.
Returns:
if we throw an exception on warnings

setThrowOnError

public void setThrowOnError(boolean b)
User-settable behavior: when to re-throw exceptions.

This allows per-instance configuration of ListingErrorHandlers. You can ask us to either throw an exception when we're called for various warning / error / fatalErrors, or simply log them and continue.

Note that the behavior of many parsers/transformers after an error is not necessarily defined!

Parameters:
b - if we should throw an exception on errors

getThrowOnError

public boolean getThrowOnError()
User-settable behavior: when to re-throw exceptions.
Returns:
if we throw an exception on errors

setThrowOnFatalError

public void setThrowOnFatalError(boolean b)
User-settable behavior: when to re-throw exceptions.

This allows per-instance configuration of ListingErrorHandlers. You can ask us to either throw an exception when we're called for various warning / error / fatalErrors, or simply log them and continue.

Note that the behavior of many parsers/transformers after a fatalError is not necessarily defined, most products will probably barf if you continue.

Parameters:
b - if we should throw an exception on fatalErrors

getThrowOnFatalError

public boolean getThrowOnFatalError()
User-settable behavior: when to re-throw exceptions.
Returns:
if we throw an exception on fatalErrors


Copyright 2006 Apache XML Project. All Rights Reserved.