Package gov.usgs.earthquake.product.io

Class XmlProductSource

java.lang.Object

org.xml.sax.helpers.DefaultHandler

gov.usgs.earthquake.product.io.XmlProductSource

All Implemented Interfaces:

ProductSource, ContentHandler, DTDHandler, EntityResolver, ErrorHandler

Direct Known Subclasses:

SearchResponseXmlProductSource

public class XmlProductSource
extends DefaultHandler
implements ProductSource

Load a product from an InputStream containing XML.

Constructor Summary

Constructors

Constructor	Description
XmlProductSource(ProductHandler out)	Create a new XmlProductSource for embedding in another default handler.
XmlProductSource(InputStream in)	Create a new XmlProductSource.

Method Summary

Modifier and Type	Method	Description
void	characters(char[] ch, int start, int length)	Override DefaultHandler characters.
void	close()	Free any resources associated with this handler.
void	closeContent()	Closes an open output stream
void	endElement(String uri, String localName, String qName)	Override DefaultHandler endElement.
protected ProductHandler	getHandler()
InputStream	openContentStream(boolean encoded)	Set up a piped output stream used during parsing.
protected void	setHandler(ProductHandler out)
void	startElement(String uri, String localName, String qName, Attributes attributes)	Override DefaultHandler startElement.
void	streamTo(ProductHandler out)	Begin reading the input stream, sending events to out.

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

XmlProductSource

public XmlProductSource(InputStream in)

Create a new XmlProductSource.

Parameters:

in - the input stream where xml is read.

XmlProductSource

public XmlProductSource(ProductHandler out)

Create a new XmlProductSource for embedding in another default handler.

Parameters:

out - the ProductHandler to receive product events.

Method Details

streamTo

public void streamTo(ProductHandler out)
              throws Exception

Begin reading the input stream, sending events to out.

Specified by:

streamTo in interface ProductSource

Parameters:

out - the receiving ProductOutput.

Throws:

Exception - if error occurs

startElement

public 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 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 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.

getHandler

protected ProductHandler getHandler()

Returns:

ProductHandler

setHandler

protected void setHandler(ProductHandler out)

Parameters:

out - ProductHandler to set

close

public void close()

Free any resources associated with this handler.

Specified by:

close in interface ProductSource

openContentStream

public InputStream openContentStream(boolean encoded)
                              throws IOException

Set up a piped output stream used during parsing. The XmlProductSource parsing thread starts a background thread to deliver content to the handler, then continues parsing XML and delivers parsed content via the piped streams. If xml parsing completes as expected, the parsing thread will close the connection in closeContent(). If errors occur, the objects handling the product source object call closeContent to ensure the resource is closed.

Parameters:

encoded - if it needs to decode base 64 content

Returns:

a input stream of the Piped output stream

Throws:

IOException - if io error occurs

closeContent

public void closeContent()

Closes an open output stream