src.java.com.ctc.wstx.dom.DOMWrappingWriter Maven / Gradle / Ivy
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package com.ctc.wstx.dom;
import java.util.*;
import javax.xml.XMLConstants;
import javax.xml.namespace.*;
import javax.xml.stream.*;
import javax.xml.transform.dom.DOMResult;
import org.w3c.dom.*;
import org.codehaus.stax2.XMLStreamLocation2;
import org.codehaus.stax2.XMLStreamReader2;
import org.codehaus.stax2.XMLStreamWriter2;
import org.codehaus.stax2.validation.ValidationProblemHandler;
import org.codehaus.stax2.validation.XMLValidationSchema;
import org.codehaus.stax2.validation.XMLValidator;
import com.ctc.wstx.api.WriterConfig;
import com.ctc.wstx.api.WstxOutputProperties;
import com.ctc.wstx.util.EmptyNamespaceContext;
/**
* This is an adapter class that allows building a DOM tree using
* {@link XMLStreamWriter} interface.
*
* Note that the implementation is only to be used for use with
* javax.xml.transform.dom.DOMResult.
*
* Some notes regarding missing/incomplete functionality:
*
*
*
* @author Tatu Saloranta
* @author Dan Diephouse
*/
public class DOMWrappingWriter
implements XMLStreamWriter2
{
/*
////////////////////////////////////////////////////
// Configuration
////////////////////////////////////////////////////
*/
protected final WriterConfig mConfig;
protected final boolean mNsAware;
protected final boolean mNsRepairing;
/**
* This member variable is to keep information about encoding
* that seems to be used for the document (or fragment) to output,
* if known.
*/
protected String mEncoding = null;
/**
* If we are being given info about existing bindings, it'll come
* as a NamespaceContet.
*/
protected NamespaceContext mNsContext;
/*
////////////////////////////////////////////////////
// State
////////////////////////////////////////////////////
*/
/**
* We need a reference to the document hosting nodes to
* be able to create new nodes
*/
protected final Document mDocument;
/**
* This element is the current context element, under which
* all other nodes are added, until matching end element
* is output. Null outside of the main element tree.
*/
protected Element mParentElem;
/**
* This element is non-null right after a call to
* either writeStartElement and
* writeEmptyElement, and can be used to
* add attributes and namespace declarations.
*/
protected Element mOpenElement;
/*
////////////////////////////////////////////////////
// Life-cycle
////////////////////////////////////////////////////
*/
private DOMWrappingWriter(WriterConfig cfg, Node treeRoot)
throws XMLStreamException
{
if (treeRoot == null) {
throw new IllegalArgumentException("Can not pass null Node for constructing a DOM-based XMLStreamWriter");
}
mConfig = cfg;
mNsAware = cfg.willSupportNamespaces();
mNsRepairing = mNsAware && cfg.automaticNamespacesEnabled();
/* 15-Sep-2007, TSa: Repairing mode not yet supported, so better
* signal that right away
*/
if (mNsRepairing) {
throw new XMLStreamException("Repairing mode not (yet) supported with DOM-backed writer");
}
Element elem = null;
/* Ok; we need a document node; or an element node; or a document
* fragment node.
*/
switch (treeRoot.getNodeType()) {
case Node.DOCUMENT_NODE: // fine
mDocument = (Document) treeRoot;
/* Should try to find encoding, version and stand-alone
* settings... but is there a standard way of doing that?
*/
break;
case Node.ELEMENT_NODE: // can make sub-tree... ok
mDocument = treeRoot.getOwnerDocument();
elem = (Element) treeRoot;
break;
case Node.DOCUMENT_FRAGMENT_NODE: // as with element...
mDocument = treeRoot.getOwnerDocument();
// Above types are fine
break;
default: // other Nodes not usable
throw new XMLStreamException("Can not create an XMLStreamWriter for a DOM node of type "+treeRoot.getClass());
}
if (mDocument == null) {
throw new XMLStreamException("Can not create an XMLStreamWriter for given node (of type "+treeRoot.getClass()+"): did not have owner document");
}
mParentElem = mOpenElement = elem;
}
public static DOMWrappingWriter createFrom(WriterConfig cfg, DOMResult dst)
throws XMLStreamException
{
Node rootNode = dst.getNode();
return new DOMWrappingWriter(cfg, rootNode);
}
/*
////////////////////////////////////////////////////
// XMLStreamWriter API (Stax 1.0)
////////////////////////////////////////////////////
*/
public void close() {
// NOP
}
public void flush() {
// NOP
}
public NamespaceContext getNamespaceContext()
{
if (!mNsAware) {
return EmptyNamespaceContext.getInstance();
}
// !!! TBI:
return mNsContext;
}
public String getPrefix(String uri)
{
if (!mNsAware) {
return null;
}
// !!! TBI:
return null;
}
public Object getProperty(String name) {
// !!! TBI
return null;
}
public void setDefaultNamespace(String uri) {
// !!! TBI
}
public void setNamespaceContext(NamespaceContext context) {
mNsContext = context;
}
public void setPrefix(String prefix, String uri) {
// !!! TBI
}
public void writeAttribute(String localName, String value)
{
outputAttribute(null, null, localName, value);
}
public void writeAttribute(String nsURI, String localName, String value) {
outputAttribute(nsURI, null, localName, value);
}
public void writeAttribute(String prefix, String nsURI, String localName, String value)
{
outputAttribute(nsURI, prefix, localName, value);
}
public void writeCData(String data) {
appendLeaf(mDocument.createCDATASection(data));
}
public void writeCharacters(char[] text, int start, int len)
{
writeCharacters(new String(text, start, len));
}
public void writeCharacters(String text) {
appendLeaf(mDocument.createTextNode(text));
}
public void writeComment(String data) {
appendLeaf(mDocument.createCDATASection(data));
}
public void writeDefaultNamespace(String nsURI)
{
writeNamespace(null, nsURI);
}
public void writeDTD(String dtd)
{
// Would have to parse, not worth trying...
reportUnsupported("writeDTD()");
}
public void writeEmptyElement(String localName) {
writeEmptyElement(null, localName);
}
public void writeEmptyElement(String nsURI, String localName)
{
/* Note: can not just call writeStartElement(), since this
* element will only become the open elem, but not a parent elem
*/
createStartElem(nsURI, null, localName, true);
}
public void writeEmptyElement(String prefix, String localName, String nsURI)
{
createStartElem(nsURI, prefix, localName, true);
}
public void writeEndDocument()
{
mParentElem = mOpenElement = null;
}
public void writeEndElement()
{
// Simple, just need to traverse up... if we can
if (mParentElem == null) {
throw new IllegalStateException("No open start element to close");
}
mOpenElement = null; // just in case it was open
Node parent = mParentElem.getParentNode();
mParentElem = (parent == mDocument) ? null : (Element) parent;
}
public void writeEntityRef(String name) {
appendLeaf(mDocument.createEntityReference(name));
}
public void writeNamespace(String prefix, String nsURI)
{
boolean defNS = (prefix == null || prefix.length() == 0);
if (!mNsAware) {
if (defNS) {
outputAttribute(null, null, "xmlns", nsURI);
} else {
outputAttribute(null, "xmlns", prefix, nsURI);
}
} else {
// !!! TBI
/* For now, let's output it (in non-repairing ns-aware
* mode), but not keep track of bindings.
*/
if (defNS) {
outputAttribute(XMLConstants.XMLNS_ATTRIBUTE_NS_URI, null, "xmlns", nsURI);
} else {
outputAttribute(XMLConstants.XMLNS_ATTRIBUTE_NS_URI, "xmlns", prefix, nsURI);
}
}
}
public void writeProcessingInstruction(String target) {
writeProcessingInstruction(target, null);
}
public void writeProcessingInstruction(String target, String data) {
appendLeaf(mDocument.createProcessingInstruction(target, data));
}
public void writeSpace(char[] text, int start, int len) {
writeSpace(new String(text, start, len));
}
public void writeSpace(String text) {
/* This won't work all that well, given there's no way to
* prevent quoting/escaping. But let's do what we can, since
* the alternative (throwing an exception) doesn't seem
* especially tempting choice.
*/
writeCharacters(text);
}
public void writeStartDocument()
{
writeStartDocument(WstxOutputProperties.DEFAULT_OUTPUT_ENCODING,
WstxOutputProperties.DEFAULT_XML_VERSION);
}
public void writeStartDocument(String version)
{
writeStartDocument(null, version);
}
public void writeStartDocument(String encoding, String version)
{
// Is there anything here we can or should do? No?
mEncoding = encoding;
}
public void writeStartElement(String localName) {
writeStartElement(null, localName);
}
public void writeStartElement(String nsURI, String localName)
{
createStartElem(nsURI, null, localName, false);
}
public void writeStartElement(String prefix, String localName, String nsURI)
{
createStartElem(nsURI, prefix, localName, false);
}
/*
////////////////////////////////////////////////////
// XMLStreamWriter2 API (Stax2 v2.0)
////////////////////////////////////////////////////
*/
public boolean isPropertySupported(String name)
{
// !!! TBI: not all these properties are really supported
return mConfig.isPropertySupported(name);
}
public boolean setProperty(String name, Object value)
{
/* Note: can not call local method, since it'll return false for
* recognized but non-mutable properties
*/
return mConfig.setProperty(name, value);
}
public XMLValidator validateAgainst(XMLValidationSchema schema)
throws XMLStreamException
{
// !!! TBI
return null;
}
public XMLValidator stopValidatingAgainst(XMLValidationSchema schema)
throws XMLStreamException
{
// !!! TBI
return null;
}
public XMLValidator stopValidatingAgainst(XMLValidator validator)
throws XMLStreamException
{
// !!! TBI
return null;
}
public ValidationProblemHandler setValidationProblemHandler(ValidationProblemHandler h)
{
// Not implemented by the basic reader
return null;
}
public XMLStreamLocation2 getLocation() {
return null;
}
public String getEncoding() {
return mEncoding;
}
public void writeCData(char[] text, int start, int len)
throws XMLStreamException
{
writeCData(new String(text, start, len));
}
public void writeDTD(String rootName, String systemId, String publicId,
String internalSubset)
throws XMLStreamException
{
/* Alas: although we can create a DocumentType object, there
* doesn't seem to be a way to attach it in DOM-2!
*/
if (mParentElem != null) {
throw new IllegalStateException("Operation only allowed to the document before adding root element");
}
reportUnsupported("writeDTD()");
}
public void writeFullEndElement() throws XMLStreamException
{
// No difference with DOM
writeEndElement();
}
public void writeStartDocument(String version, String encoding,
boolean standAlone)
throws XMLStreamException
{
writeStartDocument(encoding, version);
}
/*
///////////////////////////////
// Stax2, pass-through methods
///////////////////////////////
*/
public void writeRaw(String text)
throws XMLStreamException
{
reportUnsupported("writeRaw()");
}
public void writeRaw(String text, int start, int offset)
throws XMLStreamException
{
reportUnsupported("writeRaw()");
}
public void writeRaw(char[] text, int offset, int length)
throws XMLStreamException
{
reportUnsupported("writeRaw()");
}
public void copyEventFromReader(XMLStreamReader2 r, boolean preserveEventData)
throws XMLStreamException
{
// !!! TBI
}
/*
///////////////////////////////
// Internal methods
///////////////////////////////
*/
protected void appendLeaf(Node n)
throws IllegalStateException
{
if (mParentElem == null) { // to add to document
mDocument.appendChild(n);
} else {
// Will also close the open element, if any
mOpenElement = null;
mParentElem.appendChild(n);
}
}
protected void createStartElem(String nsURI, String prefix, String localName, boolean isEmpty)
{
Element elem;
if (mNsAware) {
if (mNsRepairing) {
/* Need to ensure proper bindings... ugh.
* May change prefix
*/
// !!! TBI
}
if (prefix != null && prefix.length() > 0) {
localName = prefix + ":" + localName;
}
elem = mDocument.createElementNS(nsURI, localName);
} else { // non-ns, simple
if (prefix != null && prefix.length() > 0) {
localName = prefix + ":" + localName;
}
elem = mDocument.createElement(localName);
}
appendLeaf(elem);
mOpenElement = elem;
if (!isEmpty) {
mParentElem = elem;
}
}
protected void outputAttribute(String nsURI, String prefix, String localName, String value)
{
if (mOpenElement == null) {
throw new IllegalStateException("No currently open START_ELEMENT, cannot write attribute");
}
if (mNsAware) {
if (mNsRepairing) {
/* Need to ensure proper bindings... ugh.
* May change prefix
*/
// !!! TBI
}
if (prefix != null && prefix.length() > 0) {
localName = prefix + ":" + localName;
}
mOpenElement.setAttributeNS(nsURI, localName, value);
} else { // non-ns, simple
if (prefix != null && prefix.length() > 0) {
localName = prefix + ":" + localName;
}
mOpenElement.setAttribute(localName, value);
}
}
private void reportUnsupported(String operName)
{
throw new UnsupportedOperationException(operName+" can not be used with DOM-backed writer");
}
}