Class TreeWalker
- All Implemented Interfaces:
SourceLocator
,PullProvider
,UnfailingPullProvider
,Location
,Locator
-
Method Summary
Modifier and TypeMethodDescriptionvoid
close()
Close the event reader.current()
Get the event most recently returned by next(), or by other calls that change the position, for example getStringValue() and skipToMatchingEnd().Get an atomic value.Get the attributes associated with the current element.int
Return the character position where the current document event ends.int
Return the line number where the current document event ends.Get the namePool used to lookup all name codes and namespace codesGet the namespace declarations associated with the current element.Get the NodeName identifying the name of the current node.Get configuration information.Return the public identifier for the current document event.Get the type annotation of the current attribute or element node, or atomic value.Get the location of the current event.Get the string value of the current attribute, text node, processing-instruction, or atomic value.Return the system identifier for the current document event.Get a list of unparsed entities.static UnfailingPullProvider
makeTreeWalker
(NodeInfo startNode) Factory method to get a tree walker starting an a given nodenext()
Get the next eventGet an immutable copy of this Location object.void
Set configuration information.Skip the current subtree.
-
Method Details
-
makeTreeWalker
Factory method to get a tree walker starting an a given node- Parameters:
startNode
- the start node- Returns:
- a PullProvider that delivers events associated with the subtree starting at the given node
-
setPipelineConfiguration
Set configuration information. This must only be called before any events have been read.- Specified by:
setPipelineConfiguration
in interfacePullProvider
- Parameters:
pipe
- the pipeline configuration
-
getPipelineConfiguration
Get configuration information.- Specified by:
getPipelineConfiguration
in interfacePullProvider
- Returns:
- the pipeline configuration
-
next
Get the next event- Specified by:
next
in interfacePullProvider
- Specified by:
next
in interfaceUnfailingPullProvider
- Returns:
- an Event object indicating the type of event. The code
PullEvent.END_OF_INPUT
is returned if there are no more events to return. - Throws:
XPathException
- if a dynamic error occurs
-
current
Get the event most recently returned by next(), or by other calls that change the position, for example getStringValue() and skipToMatchingEnd(). This method does not change the position of the PullProvider.- Specified by:
current
in interfacePullProvider
- Specified by:
current
in interfaceUnfailingPullProvider
- Returns:
- the current event
-
getAttributes
Get the attributes associated with the current element. This method must be called only after a START_ELEMENT event has been notified. The contents of the returned AttributeMap are immutable.Attributes may be read before or after reading the namespaces of an element, but must not be read after the first child node has been read, or after calling one of the methods skipToEnd(), getStringValue(), or getTypedValue().
- Specified by:
getAttributes
in interfacePullProvider
- Specified by:
getAttributes
in interfaceUnfailingPullProvider
- Returns:
- an AttributeMap representing the attributes of the element that has just been notified.
-
getNamespaceDeclarations
Get the namespace declarations associated with the current element. This method must be called only after a START_ELEMENT event has been notified. In the case of a top-level START_ELEMENT event (that is, an element that either has no parent node, or whose parent is not included in the sequence being read), the NamespaceDeclarations object returned will contain a namespace declaration for each namespace that is in-scope for this element node. In the case of a non-top-level element, the NamespaceDeclarations will contain a set of namespace declarations and undeclarations, representing the differences between this element and its parent.It is permissible for this method to return namespace declarations that are redundant.
The NamespaceDeclarations object is guaranteed to remain unchanged until the next START_ELEMENT event, but may then be overwritten. The object should not be modified by the client.
Namespaces may be read before or after reading the attributes of an element, but must not be read after the first child node has been read, or after calling one of the methods skipToEnd(), getStringValue(), or getTypedValue().
- Specified by:
getNamespaceDeclarations
in interfacePullProvider
- Specified by:
getNamespaceDeclarations
in interfaceUnfailingPullProvider
- Returns:
- the namespace declarations associated with the current START_ELEMENT event.
-
skipToMatchingEnd
Skip the current subtree. This method may be called only immediately after a START_DOCUMENT or START_ELEMENT event. This call returns the matching END_DOCUMENT or END_ELEMENT event; the next call on next() will return the event following the END_DOCUMENT or END_ELEMENT.- Specified by:
skipToMatchingEnd
in interfacePullProvider
- Specified by:
skipToMatchingEnd
in interfaceUnfailingPullProvider
- Returns:
- the matching END_DOCUMENT or END_ELEMENT event
-
close
public void close()Close the event reader. This indicates that no further events are required. It is not necessary to close an event reader afterPullEvent.END_OF_INPUT
has been reported, but it is recommended to close it if reading terminates prematurely. Once an event reader has been closed, the effect of further calls on next() is undefined.- Specified by:
close
in interfacePullProvider
- Specified by:
close
in interfaceUnfailingPullProvider
-
getNamePool
Get the namePool used to lookup all name codes and namespace codes- Returns:
- the namePool
-
getNodeName
Get the NodeName identifying the name of the current node. This method can be used after thePullEvent.START_ELEMENT
,PullEvent.PROCESSING_INSTRUCTION
,PullEvent.ATTRIBUTE
, orPullEvent.NAMESPACE
events. With some PullProvider implementations, it can also be used afterPullEvent.END_ELEMENT
, but this is not guaranteed: a client who requires the information at that point (for example, to do serialization) should insert anElementNameTracker
into the pipeline. If called at other times, the result is undefined and may result in an IllegalStateException. If called when the current node is an unnamed namespace node (a node representing the default namespace) the returned value is null.- Specified by:
getNodeName
in interfacePullProvider
- Specified by:
getNodeName
in interfaceUnfailingPullProvider
- Returns:
- the NodeName. The NodeName can be used to obtain the prefix, local name, and namespace URI.
-
getStringValue
Get the string value of the current attribute, text node, processing-instruction, or atomic value. This method cannot be used to obtain the string value of an element, or of a namespace node. If the most recent event was anything other thanPullEvent.START_ELEMENT
,PullEvent.TEXT
,PullEvent.PROCESSING_INSTRUCTION
, orPullEvent.ATOMIC_VALUE
, the result is undefined.- Specified by:
getStringValue
in interfacePullProvider
- Specified by:
getStringValue
in interfaceUnfailingPullProvider
- Returns:
- the string value of the current node, if defined
-
getSchemaType
Get the type annotation of the current attribute or element node, or atomic value. The result of this method is undefined unless the most recent event was START_ELEMENT, START_CONTENT, ATTRIBUTE, or ATOMIC_VALUE.- Specified by:
getSchemaType
in interfacePullProvider
- Specified by:
getSchemaType
in interfaceUnfailingPullProvider
- Returns:
- the type code.
-
getAtomicValue
Get an atomic value. This call may be used only when the last event reported was ATOMIC_VALUE. This indicates that the PullProvider is reading a sequence that contains a free-standing atomic value; it is never used when reading the content of a node.- Specified by:
getAtomicValue
in interfacePullProvider
- Specified by:
getAtomicValue
in interfaceUnfailingPullProvider
- Returns:
- the atomic value
-
getSourceLocator
Get the location of the current event. For an event stream representing a real document, the location information should identify the location in the lexical XML source. For a constructed document, it should identify the location in the query or stylesheet that caused the node to be created. A value of null can be returned if no location information is available.- Specified by:
getSourceLocator
in interfacePullProvider
- Specified by:
getSourceLocator
in interfaceUnfailingPullProvider
- Returns:
- the SourceLocator giving the location of the current event, or null if no location information is available
-
getPublicId
Return the public identifier for the current document event.The return value is the public identifier of the document entity or of the external parsed entity in which the markup that triggered the event appears.
- Specified by:
getPublicId
in interfaceLocation
- Specified by:
getPublicId
in interfaceLocator
- Specified by:
getPublicId
in interfaceSourceLocator
- Returns:
- A string containing the public identifier, or null if none is available.
- See Also:
-
getSystemId
Return the system identifier for the current document event.The return value is the system identifier of the document entity or of the external parsed entity in which the markup that triggered the event appears.
If the system identifier is a URL, the parser must resolve it fully before passing it to the application.
- Specified by:
getSystemId
in interfaceLocation
- Specified by:
getSystemId
in interfaceLocator
- Specified by:
getSystemId
in interfaceSourceLocator
- Returns:
- A string containing the system identifier, or null if none is available.
- See Also:
-
getLineNumber
public int getLineNumber()Return the line number where the current document event ends.Warning: The return value from the method is intended only as an approximation for the sake of error reporting; it is not intended to provide sufficient information to edit the character content of the original XML document.
The return value is an approximation of the line number in the document entity or external parsed entity where the markup that triggered the event appears.
- Specified by:
getLineNumber
in interfaceLocation
- Specified by:
getLineNumber
in interfaceLocator
- Specified by:
getLineNumber
in interfaceSourceLocator
- Returns:
- The line number, or -1 if none is available.
- See Also:
-
getColumnNumber
public int getColumnNumber()Return the character position where the current document event ends.Warning: The return value from the method is intended only as an approximation for the sake of error reporting; it is not intended to provide sufficient information to edit the character content of the original XML document.
The return value is an approximation of the column number in the document entity or external parsed entity where the markup that triggered the event appears.
- Specified by:
getColumnNumber
in interfaceLocation
- Specified by:
getColumnNumber
in interfaceLocator
- Specified by:
getColumnNumber
in interfaceSourceLocator
- Returns:
- The column number, or -1 if none is available.
- See Also:
-
saveLocation
Get an immutable copy of this Location object. By default Location objects may be mutable, so they should not be saved for later use. The result of this operation holds the same location information, but in an immutable form.- Specified by:
saveLocation
in interfaceLocation
- Returns:
- an immutable copy (which may be the original object, if it is already immutable)
-
getUnparsedEntities
Get a list of unparsed entities.- Specified by:
getUnparsedEntities
in interfacePullProvider
- Specified by:
getUnparsedEntities
in interfaceUnfailingPullProvider
- Returns:
- a list of unparsed entities, or null if the information is not available, or an empty list if there are no unparsed entities.
-