Package gov.usgs.util

Class SAXAdapter

java.lang.Object

org.xml.sax.helpers.DefaultHandler

gov.usgs.util.SAXAdapter

All Implemented Interfaces:

ContentHandler, DTDHandler, EntityResolver, ErrorHandler

Direct Known Subclasses:

EventAddonParser, RegionsHandler, URLNotificationParser

public class SAXAdapter
extends DefaultHandler

SAXAdapter is a sax handler that accumulates element content, which is a common sax handler task. Users should be cautious because this in some ways removes efficiency gained by handling streaming events, because element content is being buffered. One buffer for each element nesting is maintained, so this works best for shallow documents, whose elements contain little content.

Constructor Summary

Constructors

Constructor	Description
SAXAdapter()

Method Summary

Modifier and Type	Method	Description
final void	characters(char[] ch, int start, int length)	Override DefaultHandler characters.
final void	endElement(String uri, String localName, String qName)	Override DefaultHandler endElement.
void	onEndElement(String uri, String localName, String qName, String content)	SAXAdapter end element handler.
void	onStartElement(String uri, String localName, String qName, Attributes attributes)	SAXAdapter start element handler.
final Exception	parse(InputStream xml)	Use this handler to parse an input stream.
final Exception	parse(String xml)	Use this handler to parse a string.
final void	startElement(String uri, String localName, String qName, Attributes attributes)	Override DefaultHandler startElement.

Methods inherited from class org.xml.sax.helpers.DefaultHandler

endDocument, endPrefixMapping, error, fatalError, ignorableWhitespace, notationDecl, processingInstruction, resolveEntity, setDocumentLocator, skippedEntity, startDocument, startPrefixMapping, unparsedEntityDecl, warning

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.xml.sax.ContentHandler

declaration

Constructor Details

SAXAdapter

public SAXAdapter()

Method Details

onStartElement

public void onStartElement(String uri,
 String localName,
 String qName,
 Attributes attributes)
                    throws SAXException

SAXAdapter start element handler.

Parameters:

uri - element uri.

localName - element localName.

qName - element qName.

attributes - element attributes.

Throws:

SAXException - if there is an error.

onEndElement

public void onEndElement(String uri,
 String localName,
 String qName,
 String content)
                  throws SAXException

SAXAdapter end element handler. Content only includes characters that were read from this element, NOT any characters from child elements.

Parameters:

uri - element uri.

localName - element localName.

qName - element qName.

content - element content.

Throws:

SAXException - if onEndElement throws a SAXException.

startElement

public final void startElement(String uri,
 String localName,
 String qName,
 Attributes attributes)
                        throws SAXException

Override DefaultHandler startElement. Adds a new element content buffer and calls onStartElement.

Specified by:

startElement in interface ContentHandler

Overrides:

startElement in class DefaultHandler

Parameters:

uri - element uri.

localName - element localName.

qName - element qName.

attributes - element attributes.

Throws:

SAXException - if onStartElement throws a SAXException.

endElement

public final void endElement(String uri,
 String localName,
 String qName)
                      throws SAXException

Override DefaultHandler endElement. Retrieves element content buffer and passes it to onEndElement.

Specified by:

endElement in interface ContentHandler

Overrides:

endElement in class DefaultHandler

Parameters:

uri - element uri.

localName - element localName.

qName - element qName.

Throws:

SAXException - if onEndElement throws a SAXException.

characters

public final void characters(char[] ch,
 int start,
 int length)
                      throws SAXException

Override DefaultHandler characters. Appends content to current element buffer, or skips if before first element.

Specified by:

characters in interface ContentHandler

Overrides:

characters in class DefaultHandler

Parameters:

ch - content.

start - position in content to read.

length - lenth of content to read.

Throws:

SAXException - never.

parse

public final Exception parse(String xml)

Use this handler to parse a string. Wraps string bytes in a ByteArrayInputStream.

Parameters:

xml - string containing xml to parse.

Returns:

any exception that occurs while parsing, or null if no exceptions occur.

parse

public final Exception parse(InputStream xml)

Use this handler to parse an input stream. Uses self as a content and error handler in an XMLReader. If an error occurs, use getException to retrieve the error.

Parameters:

xml - input stream of xml to parse.

Returns:

any exception that occurs while parsing, or null if no exceptions occur.