Class TaggedContentHandler

  • All Implemented Interfaces:
    ContentHandler, DTDHandler, EntityResolver, ErrorHandler

    public class TaggedContentHandler
    extends ContentHandlerDecorator
    A content handler decorator that tags potential exceptions so that the handler that caused the exception can easily be identified. This is done by using the TaggedSAXException class to wrap all thrown SAXExceptions. See below for an example of using this class.
     TaggedContentHandler handler = new TaggedContentHandler(...);
     try {
         // Processing that may throw an SAXException either from this handler
         // or from some other XML parsing activity
         processXML(handler);
     } catch (SAXException e) {
         if (handler.isCauseOf(e)) {
             // The exception was caused by this handler.
             // Use e.getCause() to get the original exception.
         } else {
             // The exception was caused by something else.
         }
     }
     

    Alternatively, the throwIfCauseOf(Exception) method can be used to let higher levels of code handle the exception caused by this stream while other processing errors are being taken care of at this lower level.

     TaggedContentHandler handler = new TaggedContentHandler(...);
     try {
         processXML(handler);
     } catch (SAXException e) {
         stream.throwIfCauseOf(e);
         // ... or process the exception that was caused by something else
     }
     
    See Also:
    TaggedSAXException
    • Constructor Detail

      • TaggedContentHandler

        public TaggedContentHandler​(ContentHandler proxy)
        Creates a tagging decorator for the given content handler.
        Parameters:
        proxy - content handler to be decorated
    • Method Detail

      • isCauseOf

        public boolean isCauseOf​(SAXException exception)
        Tests if the given exception was caused by this handler.
        Parameters:
        exception - an exception
        Returns:
        true if the exception was thrown by this handler, false otherwise
      • throwIfCauseOf

        public void throwIfCauseOf​(Exception exception)
                            throws SAXException
        Re-throws the original exception thrown by this handler. This method first checks whether the given exception is a TaggedSAXException wrapper created by this decorator, and then unwraps and throws the original wrapped exception. Returns normally if the exception was not thrown by this handler.
        Parameters:
        exception - an exception
        Throws:
        SAXException - original exception, if any, thrown by this handler