The system property that determines which Factory implementation * to create is named "org.apache.xml.utils.DTMFactory". This * property names a concrete subclass of the DTMFactory abstract * class. If the property is not defined, a platform default is be used.
* *An instance of this class
Note: this class is incomplete right now. It will be pretty much * modeled after javax.xml.transform.TransformerFactory in terms of its * factory support.
* *State: In progress!!
*/ public abstract class DTMManager { /** The default property name to load the manager. */ private static final String defaultPropName = "org.apache.xml.dtm.DTMManager"; /** * Factory for creating XMLString objects. * %TBD% Make this set by the caller. */ protected XMLStringFactory m_xsf = null; /** * Default constructor is protected on purpose. */ protected DTMManager(){} /** * Get the XMLStringFactory used for the DTMs. * * * @return a valid XMLStringFactory object, or null if it hasn't been set yet. */ public XMLStringFactory getXMLStringFactory() { return m_xsf; } /** * Set the XMLStringFactory used for the DTMs. * * * @param xsf a valid XMLStringFactory object, should not be null. */ public void setXMLStringFactory(XMLStringFactory xsf) { m_xsf = xsf; } /** * Obtain a new instance of aDTMManager.
* This static method creates a new factory instance
* This method uses the following ordered lookup procedure to determine
* the DTMManager implementation class to
* load:
* org.apache.xml.dtm.DTMManager system
* property.
* META-INF/services/javax.xml.parsers.DTMManager
* in jars available to the runtime.
* DTMManager classname, which is
* org.apache.xml.dtm.ref.DTMManagerDefault.
*
* DTMManager it can use the factory to configure
* and obtain parser instances.
*
* @return new DTMManager instance, never null.
*
* @throws DTMConfigurationException
* if the implementation is not available or cannot be instantiated.
*/
public static DTMManager newInstance(XMLStringFactory xsf)
throws DTMConfigurationException
{
DTMManager factoryImpl = null;
try {
factoryImpl = (DTMManager) FactoryFinder.find(defaultPropName,
/* The fallback implementation class name */
"org.apache.xml.dtm.ref.DTMManagerDefault");
} catch (FactoryFinder.ConfigurationError e) {
throw new DTMConfigurationException(XMLMessages.createXMLMessage(XMLErrorResources.ER_NO_DEFAULT_IMPL, null)); //"No default implementation found");
}
if (factoryImpl == null)
{
throw new DTMConfigurationException(XMLMessages.createXMLMessage(XMLErrorResources.ER_NO_DEFAULT_IMPL, null)); //"No default implementation found");
}
factoryImpl.setXMLStringFactory(xsf);
return factoryImpl;
}
/**
* Get an instance of a DTM, loaded with the content from the
* specified source. If the unique flag is true, a new instance will
* always be returned. Otherwise it is up to the DTMManager to return a
* new instance or an instance that it already created and may be being used
* by someone else.
*
* (More parameters may eventually need to be added for error handling
* and entity resolution, and to better control selection of implementations.)
*
* @param source the specification of the source object, which may be null,
* in which case it is assumed that node construction will take
* by some other means.
* @param unique true if the returned DTM must be unique, probably because it
* is going to be mutated.
* @param whiteSpaceFilter Enables filtering of whitespace nodes, and may
* be null.
* @param incremental true if the DTM should be built incrementally, if
* possible.
* @param doIndexing true if the caller considers it worth it to use
* indexing schemes.
*
* @return a non-null DTM reference.
*/
public abstract DTM getDTM(javax.xml.transform.Source source,
boolean unique, DTMWSFilter whiteSpaceFilter,
boolean incremental, boolean doIndexing);
/**
* Get the instance of DTM that "owns" a node handle.
*
* @param nodeHandle the nodeHandle.
*
* @return a non-null DTM reference.
*/
public abstract DTM getDTM(int nodeHandle);
/**
* Given a W3C DOM node, try and return a DTM handle.
* Note: calling this may be non-optimal.
*
* @param node Non-null reference to a DOM node.
*
* @return a valid DTM handle.
*/
public abstract int getDTMHandleFromNode(org.w3c.dom.Node node);
/**
* Creates a DTM representing an empty DocumentFragment object.
* @return a non-null DTM reference.
*/
public abstract DTM createDocumentFragment();
/**
* Release a DTM either to a lru pool, or completely remove reference.
* DTMs without system IDs are always hard deleted.
* State: experimental.
*
* @param dtm The DTM to be released.
* @param shouldHardDelete True if the DTM should be removed no matter what.
* @return true if the DTM was removed, false if it was put back in a lru pool.
*/
public abstract boolean release(DTM dtm, boolean shouldHardDelete);
/**
* Create a new DTMIterator based on an XPath
* UnionExpr.
*
* @param xpathCompiler ??? Somehow we need to pass in a subpart of the
* expression. I hate to do this with strings, since the larger expression
* has already been parsed.
*
* @param pos The position in the expression.
* @return The newly created DTMIterator.
*/
public abstract DTMIterator createDTMIterator(Object xpathCompiler,
int pos);
/**
* Create a new DTMIterator based on an XPath
* UnionExpr.
*
* @param xpathString Must be a valid string expressing a
* UnionExpr.
*
* @param presolver An object that can resolve prefixes to namespace URLs.
*
* @return The newly created DTMIterator.
*/
public abstract DTMIterator createDTMIterator(String xpathString,
PrefixResolver presolver);
/**
* Create a new DTMIterator based only on a whatToShow
* and a DTMFilter. The traversal semantics are defined as the
* descendant access.
*
* Note that DTMIterators may not be an exact match to DOM
* NodeIterators. They are initialized and used in much the same way
* as a NodeIterator, but their response to document mutation is not
* currently defined.
*
* @param whatToShow This flag specifies which node types may appear in
* the logical view of the tree presented by the iterator. See the
* description of NodeFilter for the set of possible
* SHOW_ values.These flags can be combined using
* OR.
* @param filter The NodeFilter to be used with this
* DTMFilter, or null to indicate no filter.
* @param entityReferenceExpansion The value of this flag determines
* whether entity reference nodes are expanded.
*
* @return The newly created DTMIterator.
*/
public abstract DTMIterator createDTMIterator(int whatToShow,
DTMFilter filter, boolean entityReferenceExpansion);
/**
* Create a new DTMIterator that holds exactly one node.
*
* @param node The node handle that the DTMIterator will iterate to.
*
* @return The newly created DTMIterator.
*/
public abstract DTMIterator createDTMIterator(int node);
/* Flag indicating whether an incremental transform is desired */
public static boolean m_incremental = false;
/**
* Set a flag indicating whether an incremental transform is desired
* @param incremental boolean to use to set m_incremental.
*
*/
public synchronized static boolean getIncremental()
{
return m_incremental;
}
/**
* Set a flag indicating whether an incremental transform is desired
* @param incremental boolean to use to set m_incremental.
*
*/
public synchronized static void setIncremental(boolean incremental)
{
m_incremental = incremental;
}
// -------------------- private methods --------------------
/**
* Temp debug code - this will be removed after we test everything
*/
private static boolean debug;
static
{
try
{
debug = System.getProperty("dtm.debug") != null;
}
catch (SecurityException ex){}
}
/** This value, set at compile time, controls how many bits of the
* DTM node identifier numbers are used to identify a node within a
* document, and thus sets the maximum number of nodes per
* document. The remaining bits are used to identify the DTM
* document which contains this node.
*
* If you change IDENT_DTM_NODE_BITS, be sure to rebuild _ALL_ the
* files which use it... including the IDKey testcases.
*
* (FuncGenerateKey currently uses the node identifier directly and
* thus is affected when this changes. The IDKEY results will still be
* _correct_ (presuming no other breakage), but simple equality
* comparison against the previous "golden" files will probably
* complain.)
* */
public static final int IDENT_DTM_NODE_BITS = 16;
/** When this bitmask is ANDed with a DTM node handle number, the result
* is the low bits of the node's index number within that DTM. To obtain
* the high bits, add the DTM ID portion's offset as assigned in the DTM
* Manager.
*/
public static final int IDENT_NODE_DEFAULT = (1<