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oracle.xml.scalable
Interface InfosetReader

All Superinterfaces:

java.lang.Cloneable

public interface InfosetReader

extends java.lang.Cloneable

The InfosetReader interface allows forward, read-only random access to XML. It is designed to be the lowest level and most efficient way to read XML data.

The InfosetReader is designed to iterate over XML using next() and hasNext(). The data can be accessed using methods such as getEventType(), getQName(), getLocalName() and getData(), etc.

The next() method causes the reader to read the next event.

The event type can be determined using getEventType(). The events used are same as defined in JSR-173 (StAX API).

The following table describes which methods are valid in what state. If a method is called in an invalid state the method will throw a java.lang.IllegalStateException.

The parser has two optional features

• Namespace resolution - The namespace resolution includes prefix to namespace resolution, and the reverse resolution.
• Random Access - The random access is supported using getOffset() and seek() functions. The support for this feature can be tested using seekSupported()

Valid methods for each state
Event Type	Valid Methods
All States	getEventType(), hasNext(), next(), skip(), getOffset(), seek(), getNamespaceURI(), getPrefix()
START_ELEMENT	getQName(), getAttributes(), getAttribute() getTypeName(), getPrimitiveTypeId(), isGlobal(), isNillable()
ATTRIBUTE	getQName(), getTypeName(), getPrimitiveTypeId(), getData(), getDataLength(), getDataStart(), getValue() Only occurs when element-less attributes are present, possibly to represent XPath data model.	NAMESPACE	NONE - doesn't occur.	END_ELEMENT	getQName()	CHARACTERS, CDATA, SPACE	getData(), getDataLength(), getDataStart(), getValue()	COMMENT	getData(), getDataLength(), getDataStart(), getValue()	START_DOCUMENT	getEncoding(), getVersion(), getStandalone(), getDoctype()	END_DOCUMENT	close()	PROCESSING_INSTRUCTION	getQName(), getData(), getDataLength(), getDataStart(), getValue()	START_ENTITY, END_ENTITY, ENTITY_REFERENCE	getQName()	DTD	NONE - doesn't occur

Nested Class Summary

static interface

InfosetReader.Offset For opague object representing the current position/offset in the reader.

Field Summary

static int	ATTRIBUTE Indicates an event is an attribute
static int	CDATA Indicates an event is a CDATA section
static int	CHARACTERS Indicates an event is characters
static int	COMMENT Indicates an event is a comment
static int	DTD Indicates an event is a DTD
static int	END_DOCUMENT Indicates an event is an end document
static int	END_ELEMENT Indicates an event is an end element
static int	END_ENTITY Indicates an event is the end of a resolved entity
static int	ENTITY_REFERENCE Indicates an event is an entity reference
static int	NAMESPACE Indicates an event is a namepsace
static int	PROCESSING_INSTRUCTION Indicates an event is a processing instruction
static int	SPACE Indicates an event is a space, events are only reported as SPACE if they are ignorable white space.
static int	START_DOCUMENT Indicates an event is a start document
static int	START_ELEMENT Indicates an event is a start element
static int	START_ENTITY Indicates an event is the start of a resolved entity

Method Summary

java.lang.Object	clone() Clone the reader
void	close() Frees any resources associated with this InfosetReader.
java.lang.String	getAttribute(javax.xml.namespace.QName attr) Returns the attribute value of the current element with the given name Valid only if the current event is START_ELEMENT
char[]	getData() Return the data corresponding to the current event.
int	getDataLength() Returns the length of the sequence of characters for this event within the text character array.
int	getDataStart() Returns the offset into the text character array where the first character (of this text event) is stored.
DTD	getDoctype() Gets the DTD associated with the XML data.
java.lang.String	getEncoding() Get the xml encoding declared on the xml declaration Returns null if none was declared
int	getEventFlags() Get flags specific to the event
int	getEventType() Returns an integer code that indicates the type of the event the cursor is pointing to.
java.lang.String	getNamespaceURI(java.lang.String prefix) Get Namespace URI bound to a prefix in the current scope.
InfosetReader.Offset	getOffset() Returns an opaque object representing the current position/offset in the reader.
java.lang.String	getPrefix(java.lang.String namespaceURI) Get prefix bound to Namespace URI in the current scope.
int	getPrimitiveTypeId() Get the primitive type of the element This is valid at START_ELEMENT
javax.xml.namespace.QName	getQName() Get the name of the current event type This is valid at START_ELEMENT, END_ELEMENT, PROCESSING_INSTRUCTION, START_ENTITY, ENTITY_REFERENCE, END_ENTITY events
java.lang.String	getStandalone() Get the xml standalone declared on the xml declaration Returns null if none was declared
javax.xml.namespace.QName	getTypeName() Get the type name of the element.
java.lang.String	getValue() Return the data corresponding to the current event.
java.lang.String	getVersion() Get the xml version declared on the xml declaration Returns null if none was declared
boolean	hasNext() Returns true if there are more parsing events and false if there are no more events.
boolean	isGlobal() Is the current element based on global element decl?
boolean	isNilled() Is the element nillable?
boolean	isNSResolutionSupported() Checks if Namespace resolution supported
boolean	isSeekSupported() Checks if seek is supported
void	next() Get next parsing event This method will throw an IllegalStateException if it is called after hasNext() returns false.
InfosetReader.Offset	offsetFromBytes(byte[] buf, int start) Create offset from a byte representation in the byte buffer starting at 'start' index.
byte	offsetToBytes(InfosetReader.Offset offset, byte[] buf, int start) Write a byte representation of the Offset into the byte buffer starting at 'start' index.
void	seek(InfosetReader.Offset offset) Seek to a position in the reader represented by the Offset.
void	skip() Skip this parsing event and the complete subtree This method has different behavior (as compared next()) only when the current event is START_DOCUMENT or START_ELEMENT The getEventType will return END_DOCUMENT or END_ELEMENT, skipping the content of the document or element This method will throw an IllegalStateException if it is called after hasNext() returns false.

Field Detail

START_ELEMENT

static final int START_ELEMENT

Indicates an event is a start element

See Also:

Constant Field Values

END_ELEMENT

static final int END_ELEMENT

Indicates an event is an end element

See Also:

Constant Field Values

PROCESSING_INSTRUCTION

static final int PROCESSING_INSTRUCTION

Indicates an event is a processing instruction

See Also:

Constant Field Values

CHARACTERS

static final int CHARACTERS

Indicates an event is characters

See Also:

Constant Field Values

COMMENT

static final int COMMENT

Indicates an event is a comment

See Also:

Constant Field Values

SPACE

static final int SPACE

Indicates an event is a space, events are only reported as SPACE if they are ignorable white space. Otherwise they are reported as CHARACTERS.

See Also:

Constant Field Values

START_DOCUMENT

static final int START_DOCUMENT

Indicates an event is a start document

See Also:

Constant Field Values

END_DOCUMENT

static final int END_DOCUMENT

Indicates an event is an end document

See Also:

Constant Field Values

ENTITY_REFERENCE

static final int ENTITY_REFERENCE

Indicates an event is an entity reference

See Also:

Constant Field Values

ATTRIBUTE

static final int ATTRIBUTE

Indicates an event is an attribute

See Also:

Constant Field Values

DTD

static final int DTD

Indicates an event is a DTD

See Also:

Constant Field Values

CDATA

static final int CDATA

Indicates an event is a CDATA section

See Also:

Constant Field Values

NAMESPACE

static final int NAMESPACE

Indicates an event is a namepsace

See Also:

Constant Field Values

START_ENTITY

static final int START_ENTITY

Indicates an event is the start of a resolved entity

See Also:

Constant Field Values

END_ENTITY

static final int END_ENTITY

Indicates an event is the end of a resolved entity

See Also:

Constant Field Values

Method Detail

isNSResolutionSupported

boolean isNSResolutionSupported()

Checks if Namespace resolution supported

getNamespaceURI

java.lang.String getNamespaceURI(java.lang.String prefix)

Get Namespace URI bound to a prefix in the current scope.

Parameters:

prefix - prefix to look up

Returns:

Namespace URI bound to prefix in the current scope or null is namespace resolution is not supported

getPrefix

java.lang.String getPrefix(java.lang.String namespaceURI)

Get prefix bound to Namespace URI in the current scope.

Parameters:

namespaceURI - URI of Namespace to lookup

Returns:

prefix bound to Namespace URI in current context

isSeekSupported

boolean isSeekSupported()

Checks if seek is supported

getOffset

InfosetReader.Offset getOffset()

Returns an opaque object representing the current position/offset in the reader. The Offset object can be used to seek to this position using the seek() function

Returns:

Offset or null if seek is not support

seek

void seek(InfosetReader.Offset offset)

Seek to a position in the reader represented by the Offset. This function will throw UnsupportedOperationException if seek is supported

Parameters:

offset - indicating amount to seek

offsetToBytes

byte offsetToBytes(InfosetReader.Offset offset,
                   byte[] buf,
                   int start)

Write a byte representation of the Offset into the byte buffer starting at 'start' index.

Parameters:

offset - - offset to be converted to bytes

buf - - byte array to write into

start - - start index

Returns:

number of bytes written, or -1 if buffer size is not sufficient

offsetFromBytes

InfosetReader.Offset offsetFromBytes(byte[] buf,
                                     int start)

Create offset from a byte representation in the byte buffer starting at 'start' index.

Parameters:

buf - - byte array to read from

start - - start index

Returns:

offset - offset converted from bytes in buf or null if bytes in the buf are invalid

getEventType

int getEventType()

Returns an integer code that indicates the type of the event the cursor is pointing to.

Returns:

event type at current cursor location

hasNext

boolean hasNext()

Returns true if there are more parsing events and false if there are no more events. This method will return false if the current state of the InfosetReader is END_DOCUMENT

Returns:

true if there are more events, false otherwise

next

void next()

Get next parsing event This method will throw an IllegalStateException if it is called after hasNext() returns false.

Throws:

java.lang.IllegalStateException - if this is called when hasNext() returns false

skip

void skip()

Skip this parsing event and the complete subtree This method has different behavior (as compared next()) only when the current event is START_DOCUMENT or START_ELEMENT The getEventType will return END_DOCUMENT or END_ELEMENT, skipping the content of the document or element This method will throw an IllegalStateException if it is called after hasNext() returns false.

Throws:

java.lang.IllegalStateException - if this is called when hasNext() returns false

getEncoding

java.lang.String getEncoding()

Get the xml encoding declared on the xml declaration Returns null if none was declared

Returns:

the XML encoding or null

getVersion

java.lang.String getVersion()

Get the xml version declared on the xml declaration Returns null if none was declared

Returns:

the XML version or null

getStandalone

java.lang.String getStandalone()

Get the xml standalone declared on the xml declaration Returns null if none was declared

Returns:

the XML standalone or null

getDoctype

DTD getDoctype()

Gets the DTD associated with the XML data. Returns null, if no DTD

Returns:

dtd

getQName

javax.xml.namespace.QName getQName()

Get the name of the current event type This is valid at START_ELEMENT, END_ELEMENT, PROCESSING_INSTRUCTION, START_ENTITY, ENTITY_REFERENCE, END_ENTITY events

Returns:

qname

getTypeName

javax.xml.namespace.QName getTypeName()

Get the type name of the element. This is valid at START_ELEMENT

Returns:

qname

getPrimitiveTypeId

int getPrimitiveTypeId()

Get the primitive type of the element This is valid at START_ELEMENT

Returns:

type id

isGlobal

boolean isGlobal()

Is the current element based on global element decl? This is valid at START_ELEMENT

Returns:

boolean

isNilled

boolean isNilled()

Is the element nillable? This is valid at START_ELEMENT

Returns:

boolean

getAttribute

java.lang.String getAttribute(javax.xml.namespace.QName attr)

Returns the attribute value of the current element with the given name Valid only if the current event is START_ELEMENT

Returns:

Attribute value

getValue

java.lang.String getValue()

Return the data corresponding to the current event.

Returns:

string

getData

char[] getData()

Return the data corresponding to the current event. The starting offset of the data is returned by getDataStart, and the length is returned by getDataLength.

Returns:

char array

getDataStart

int getDataStart()

Returns the offset into the text character array where the first character (of this text event) is stored.

Throws:

java.lang.IllegalStateException - if this state is not a valid data state.

getDataLength

int getDataLength()

Returns the length of the sequence of characters for this event within the text character array.

Throws:

java.lang.IllegalStateException - if this state is not a valid data state.

getEventFlags

int getEventFlags()

Get flags specific to the event

close

void close()

Frees any resources associated with this InfosetReader.

clone

java.lang.Object clone()

Clone the reader

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