src.java.org.codehaus.stax2.ri.Stax2ReaderAdapter Maven / Gradle / Ivy
package org.codehaus.stax2.ri;
import java.io.IOException;
import java.io.Writer;
import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.*;
import javax.xml.stream.util.StreamReaderDelegate;
import org.codehaus.stax2.*;
import org.codehaus.stax2.validation.*;
/**
* This adapter implements parts of {@link XMLStreamReader2}, the
* extended stream reader defined by Stax2 extension, by wrapping
* a vanilla Stax 1.0 {@link XMLStreamReader} implementation.
*
* Note: the implementation is incomplete as-is, since not all
* features needed are accessible via basic Stax 1.0 interface.
* As such, two main use cases for this wrapper are:
*
* - Serve as convenient base class for a complete implementation,
* which can use native accessors provided by the wrapped Stax
* implementation
*
* - To be used for tasks that make limited use of Stax2 API, such
* that missing parts are not needed
*
*
*/
public class Stax2ReaderAdapter
extends StreamReaderDelegate /* from Stax 1.0 */
implements XMLStreamReader2 /* From Stax2 */
,AttributeInfo
,DTDInfo
,LocationInfo
{
/**
* Number of open (start) elements currently.
*/
protected int mDepth = 0;
/*
////////////////////////////////////////////////////
// Life-cycle methods
////////////////////////////////////////////////////
*/
protected Stax2ReaderAdapter(XMLStreamReader sr)
{
super(sr);
}
/**
* Method that should be used to add dynamic support for
* {@link XMLStreamReader2}. Method will check whether the
* stream reader passed happens to be a {@link XMLStreamReader2};
* and if it is, return it properly cast. If not, it will create
* necessary wrapper to support features needed by StaxMate,
* using vanilla Stax 1.0 interface.
*/
public static XMLStreamReader2 wrapIfNecessary(XMLStreamReader sr)
{
if (sr instanceof XMLStreamReader2) {
return (XMLStreamReader2) sr;
}
return new Stax2ReaderAdapter(sr);
}
/*
////////////////////////////////////////////////////
// Stax 1.0 methods overridden
////////////////////////////////////////////////////
*/
public int next()
throws XMLStreamException
{
int type = super.next();
if (type == XMLStreamConstants.START_ELEMENT) {
++mDepth;
} else if (type == XMLStreamConstants.END_ELEMENT) {
--mDepth;
}
return type;
}
/*
////////////////////////////////////////////////////
// XMLStreamReader2 (StAX2) implementation
////////////////////////////////////////////////////
*/
// // // StAX2, per-reader configuration
public Object getFeature(String name)
{
// No features defined
return null;
}
public void setFeature(String name, Object value)
{
// No features defined
}
// NOTE: getProperty() defined in Stax 1.0 interface
public boolean isPropertySupported(String name) {
/* No way to cleanly implement this using just Stax 1.0
* interface, so let's be conservative and decline any knowledge
* of properties...
*/
return false;
}
public boolean setProperty(String name, Object value)
{
return false; // could throw an exception too
}
// // // StAX2, additional traversal methods
public void skipElement() throws XMLStreamException
{
if (getEventType() != START_ELEMENT) {
throwNotStartElem();
}
int nesting = 1; // need one more end elements than start elements
while (true) {
int type = next();
if (type == START_ELEMENT) {
++nesting;
} else if (type == END_ELEMENT) {
if (--nesting == 0) {
break;
}
}
}
}
// // // StAX2, additional attribute access
public AttributeInfo getAttributeInfo() throws XMLStreamException
{
if (getEventType() != START_ELEMENT) {
throwNotStartElem();
}
return this;
}
// // // StAX2, Additional DTD access
public DTDInfo getDTDInfo() throws XMLStreamException
{
if (getEventType() != DTD) {
return null;
}
return this;
}
// // // StAX2, Additional location information
/**
* Location information is always accessible, for this reader.
*/
public final LocationInfo getLocationInfo() {
return this;
}
// // // StAX2, Pass-through text accessors
public int getText(Writer w, boolean preserveContents)
throws IOException, XMLStreamException
{
char[] cbuf = getTextCharacters();
int start = getTextStart();
int len = getTextLength();
if (len > 0) {
w.write(cbuf, start, len);
}
return len;
}
// // // StAX 2, Other accessors
/**
* @return Number of open elements in the stack; 0 when parser is in
* prolog/epilog, 1 inside root element and so on.
*/
public int getDepth() {
return mDepth;
}
/**
* Alas, there is no way to find this out via Stax 1.0, so this
* implementation always returns false.
*/
public boolean isEmptyElement() throws XMLStreamException
{
return false;
}
public NamespaceContext getNonTransientNamespaceContext()
{
/* Too hard to construct without other info: let's bail
* and return null; this is better than return a transient
* one.
*/
return null; // never gets here
}
public String getPrefixedName()
{
switch (getEventType()) {
case START_ELEMENT:
case END_ELEMENT:
{
String prefix = getPrefix();
String ln = getLocalName();
if (prefix == null) {
return ln;
}
StringBuffer sb = new StringBuffer(ln.length() + 1 + prefix.length());
sb.append(prefix);
sb.append(':');
sb.append(ln);
return sb.toString();
}
case ENTITY_REFERENCE:
return getLocalName();
case PROCESSING_INSTRUCTION:
return getPITarget();
case DTD:
return getDTDRootName();
}
throw new IllegalStateException("Current state not START_ELEMENT, END_ELEMENT, ENTITY_REFERENCE, PROCESSING_INSTRUCTION or DTD");
}
public void closeCompletely() throws XMLStreamException
{
/* As usual, Stax 1.0 offers no generic way of doing just this.
* But let's at least call the lame basic close()
*/
close();
}
/*
////////////////////////////////////////////////////
// AttributeInfo implementation (StAX 2)
////////////////////////////////////////////////////
*/
// Already part of XMLStreamReader
//public int getAttributeCount();
public int findAttributeIndex(String nsURI, String localName)
{
if ("".equals(nsURI)) {
nsURI = null;
}
for (int i = 0, len = getAttributeCount(); i < len; ++i) {
if (getAttributeLocalName(i).equals(localName)) {
String otherUri = getAttributeNamespace(i);
if (nsURI == null) {
if (otherUri == null || otherUri.length() == 0) {
return i;
}
} else {
if (nsURI.equals(otherUri)) {
return i;
}
}
}
}
return -1;
}
public int getIdAttributeIndex()
{
for (int i = 0, len = getAttributeCount(); i < len; ++i) {
if ("ID".equals(getAttributeType(i))) {
return i;
}
}
return -1;
}
public int getNotationAttributeIndex()
{
for (int i = 0, len = getAttributeCount(); i < len; ++i) {
if ("NOTATION".equals(getAttributeType(i))) {
return i;
}
}
return -1;
}
/*
////////////////////////////////////////////////////
// DTDInfo implementation (StAX 2)
////////////////////////////////////////////////////
*/
public Object getProcessedDTD() {
return null;
}
public String getDTDRootName() {
return null;
}
public String getDTDPublicId() {
return null;
}
public String getDTDSystemId() {
return null;
}
/**
* @return Internal subset portion of the DOCTYPE declaration, if any;
* empty String if none
*/
public String getDTDInternalSubset()
{
/* According to basic Stax API, getText() should return
* the internal subset. Not all implementations agree, so
* this may or may not work.
*/
if (getEventType() == XMLStreamConstants.DTD) {
return getText();
}
return null;
}
// // StAX2, v2.0
public DTDValidationSchema getProcessedDTDSchema() {
return null;
}
/*
////////////////////////////////////////////////////
// LocationInfo implementation (StAX 2)
////////////////////////////////////////////////////
*/
// // // First, the "raw" offset accessors:
public long getStartingByteOffset() {
return -1L;
}
public long getStartingCharOffset() {
return 0;
}
public long getEndingByteOffset() throws XMLStreamException
{
return -1;
}
public long getEndingCharOffset() throws XMLStreamException
{
return -1;
}
// // // and then the object-based access methods:
public XMLStreamLocation2 getStartLocation()
{
/* We don't really know whether location given is current,
* start or end, but it's the best approximation we have
* without knowing more about impl:
*/
return getCurrentLocation();
}
public XMLStreamLocation2 getCurrentLocation()
{
// Just need to adapt; no info on parent context, if any:
return new Stax2LocationAdapter(getLocation());
}
public final XMLStreamLocation2 getEndLocation()
throws XMLStreamException
{
/* We don't really know whether location given is current,
* start or end, but it's the best approximation we have
* without knowing more about impl:
*/
return getCurrentLocation();
}
/*
////////////////////////////////////////////////////
// Stax2 validation
////////////////////////////////////////////////////
*/
public XMLValidator validateAgainst(XMLValidationSchema schema)
throws XMLStreamException
{
throwUnsupported();
return null;
}
public XMLValidator stopValidatingAgainst(XMLValidationSchema schema)
throws XMLStreamException
{
throwUnsupported();
return null;
}
public XMLValidator stopValidatingAgainst(XMLValidator validator)
throws XMLStreamException
{
throwUnsupported();
return null;
}
public ValidationProblemHandler setValidationProblemHandler(ValidationProblemHandler h)
{
return null;
}
/*
////////////////////////////////////////////////////
// Internal methods
////////////////////////////////////////////////////
*/
protected void throwUnsupported()
throws XMLStreamException
{
throw new XMLStreamException("Unsupported method");
}
protected void throwNotStartElem()
{
throw new IllegalStateException("Current state not START_ELEMENT");
}
}