@Override
public String pullNextXmlChunk() throws KettleException {
Stack<String> elementStack = xmlChunkerState.getElementStack();
XMLStreamReader xmlStreamReader = xmlChunkerState.getXmlStreamReader();
try {
while (xmlStreamReader.hasNext()) {
switch (xmlStreamReader.next()) {
case XMLStreamConstants.END_DOCUMENT:
return null;
case XMLStreamConstants.END_ELEMENT:
elementStack.pop();
break;
case XMLStreamConstants.START_ELEMENT:
elementStack.push(xmlStreamReader.getLocalName());
if (actualElementStackHasExpectedElements(xmlChunkerState)) {
return pullNextXmlChunkFromTopElementOnStack(xmlChunkerState);
}
break;
}
}
} catch (Exception e) {
throw new KettleException("a problem has arisen reading the xero xml stream", e);
}
return null;
}
private String pullNextXmlChunkFromTopElementOnStack(XMLChunkerState data)
throws KettleException {
Stack<String> elementStack = data.getElementStack();
XMLStreamReader xmlStreamReader = data.getXmlStreamReader();
int elementStackDepthOnEntry = elementStack.size();
StringWriter stringWriter = new StringWriter();
try {
XMLStreamWriter xmlStreamWriter =
data.getXmlOutputFactory().createXMLStreamWriter(stringWriter);
xmlStreamWriter.writeStartDocument(CharEncoding.UTF_8, "1.0");
// put the current element on because presumably it's the open element for the one
// that is being looked for.
XmlReaderToWriter.write(xmlStreamReader, xmlStreamWriter);
while (xmlStreamReader.hasNext() & elementStack.size() >= elementStackDepthOnEntry) {
switch (xmlStreamReader.next()) {
case XMLStreamConstants.END_DOCUMENT:
break; // handled below explicitly.
case XMLStreamConstants.END_ELEMENT:
elementStack.pop();
XmlReaderToWriter.write(xmlStreamReader, xmlStreamWriter);
break;
case XMLStreamConstants.START_ELEMENT:
elementStack.push(xmlStreamReader.getLocalName());
XmlReaderToWriter.write(xmlStreamReader, xmlStreamWriter);
break;
default:
XmlReaderToWriter.write(xmlStreamReader, xmlStreamWriter);
break;
}
}
xmlStreamWriter.writeEndDocument();
xmlStreamWriter.close();
} catch (Exception e) {
throw new KettleException("unable to process a chunk of the xero xml stream", e);
}
return stringWriter.toString();
}
/**
* Checks to see if the expected elements are present at the start of the actual current elements.
*
* @return true if the expected elements can be seen at the start of the actual elements.
*/
private boolean actualElementStackHasExpectedElements(XMLChunkerState data) {
Stack<String> actual = data.getElementStack();
Stack<String> expected = data.getExpectedContainerElementsStack();
if (actual.size() < expected.size()) {
return false;
}
for (int i = 0; i < expected.size(); i++) {
if (!actual.get(i).equals(expected.get(i))) {
return false;
}
}
return true;
}