com.amazonaws.transform

Class StaxUnmarshallerContext

java.lang.Object

com.amazonaws.transform.StaxUnmarshallerContext

public class StaxUnmarshallerContext
extends Object

Contains the unmarshalling state for the parsing of an XML response. The unmarshallers are stateless so that they can be reused, so this class holds the state while different unmarshallers work together to parse an XML response. It also tracks the current position and element depth of the document being parsed and provides utilties for accessing the next XML event from the parser, reading element text, handling attribute XML events, etc.

Field Summary

Fields

Modifier and Type	Field and Description
Stack<String>	stack

Constructor Summary

Constructors

Constructor and Description
StaxUnmarshallerContext(XMLEventReader eventReader) Constructs a new unmarshaller context using the specified source of XML events.
StaxUnmarshallerContext(XMLEventReader eventReader, Map<String,String> headers) Constructs a new unmarshaller context using the specified source of XML events, and a set of response headers.

Method Summary

Modifier and Type	Method and Description
int	getCurrentDepth() Returns the element depth of the parser's current position in the XML document being parsed.
String	getHeader(String header) Returns the value of the header with the specified name from the response, or null if not present.
Map<String,String>	getMetadata() Returns any metadata collected through metadata expressions while this context was reading the XML events from the XML document.
boolean	isInsideResponseHeader()
boolean	isStartOfDocument() Returns true if this unmarshaller context is at the very beginning of a source document (i.e.
XMLEvent	nextEvent() Returns the next XML event for the document being parsed.
String	readText() Returns the text contents of the current element being parsed.
void	registerMetadataExpression(String expression, int targetDepth, String storageKey) Registers an expression, which if matched, will cause the data for the matching element to be stored in the metadata map under the specified key.
void	setCurrentHeader(String currentHeader)
boolean	testExpression(String expression) Tests the specified expression against the current position in the XML document being parsed.
boolean	testExpression(String expression, int startingStackDepth) Tests the specified expression against the current position in the XML document being parsed, and restricts the expression to matching at the specified stack depth.

Methods inherited from class java.lang.Object

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

Field Detail

stack

public final Stack<String> stack

Constructor Detail

StaxUnmarshallerContext

public StaxUnmarshallerContext(XMLEventReader eventReader)

Constructs a new unmarshaller context using the specified source of XML events.

Parameters:

eventReader - The source of XML events for this unmarshalling context.

StaxUnmarshallerContext

public StaxUnmarshallerContext(XMLEventReader eventReader,
                               Map<String,String> headers)

Constructs a new unmarshaller context using the specified source of XML events, and a set of response headers.

Parameters:

eventReader - The source of XML events for this unmarshalling context.

headers - The set of response headers associated with this unmarshaller context.

Method Detail

setCurrentHeader

public void setCurrentHeader(String currentHeader)

isInsideResponseHeader

public boolean isInsideResponseHeader()

getHeader

public String getHeader(String header)

Returns the value of the header with the specified name from the response, or null if not present.

Parameters:

header - The name of the header to lookup.

Returns:

The value of the header with the specified name from the response, or null if not present.

readText

public String readText()
                throws XMLStreamException

Returns the text contents of the current element being parsed.

Returns:

The text contents of the current element being parsed.

Throws:

XMLStreamException

getCurrentDepth

public int getCurrentDepth()

Returns the element depth of the parser's current position in the XML document being parsed.

Returns:

The element depth of the parser's current position in the XML document being parsed.

testExpression

public boolean testExpression(String expression)

Tests the specified expression against the current position in the XML document being parsed.

Parameters:

expression - The psuedo-xpath expression to test.

Returns:

True if the expression matches the current document position, otherwise false.

testExpression

public boolean testExpression(String expression,
                              int startingStackDepth)

Tests the specified expression against the current position in the XML document being parsed, and restricts the expression to matching at the specified stack depth.

Parameters:

expression - The psuedo-xpath expression to test.

startingStackDepth - The depth in the stack representing where the expression must start matching in order for this method to return true.

Returns:

True if the specified expression matches the current position in the XML document, starting from the specified depth.

isStartOfDocument

public boolean isStartOfDocument()
                          throws XMLStreamException

Returns true if this unmarshaller context is at the very beginning of a source document (i.e. no data has been parsed from the document yet).

Returns:

true if this unmarshaller context is at the very beginning of a source document (i.e. no data has been parsed from the document yet).

Throws:

XMLStreamException

nextEvent

public XMLEvent nextEvent()
                   throws XMLStreamException

Returns the next XML event for the document being parsed.

Returns:

The next XML event for the document being parsed.

Throws:

XMLStreamException

getMetadata

public Map<String,String> getMetadata()

Returns any metadata collected through metadata expressions while this context was reading the XML events from the XML document.

Returns:

A map of any metadata collected through metadata expressions while this context was reading the XML document.

registerMetadataExpression

public void registerMetadataExpression(String expression,
                                       int targetDepth,
                                       String storageKey)

Registers an expression, which if matched, will cause the data for the matching element to be stored in the metadata map under the specified key.

Parameters:

expression - The expression an element must match in order for it's data to be pulled out and stored in the metadata map.

targetDepth - The depth in the XML document where the expression match must start.

storageKey - The key under which to store the matching element's data.