package com.dbxml.db.common.adapters;
/*
* dbXML - Native XML Database
* Copyright (c) 1999-2006 The dbXML Group, L.L.C.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* $Id: XMLSerializableAdapter.java,v 1.4 2006/02/02 18:53:47 bradford Exp $
*/
import com.dbxml.db.core.ClassResolver;
import com.dbxml.db.core.Collection;
import com.dbxml.db.core.DBException;
import com.dbxml.db.core.FaultCodes;
import com.dbxml.db.core.adapter.SimpleAdapter;
import com.dbxml.db.core.data.Key;
import com.dbxml.db.core.transaction.Transaction;
import com.dbxml.xml.XMLSerializable;
import com.dbxml.xml.dom.DOMHelper;
import com.dbxml.xml.dtsm.DTSMException;
import com.dbxml.xml.dtsm.DTSMHelper;
import com.dbxml.xml.dtsm.DocumentTable;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.ProcessingInstruction;
/**
* XMLSerializableAdapter adapts a dbXML Collection to support the management
* of dbXML XMLSerializable implementations.
*/
public final class XMLSerializableAdapter extends SimpleAdapter {
private static final String CLASSNAME = "dbxml-class";
public XMLSerializableAdapter(Collection col) {
super(col);
}
private void putObject(Transaction tx, Object key, XMLSerializable obj) throws DBException {
Document doc = DOMHelper.newDocument();
ProcessingInstruction pi = doc.createProcessingInstruction(CLASSNAME, obj.getClass().getName());
doc.appendChild(pi);
Node node = obj.streamToXML(doc);
doc.appendChild(node);
DocumentTable dt;
try {
dt = DTSMHelper.documentToTable(doc, col.getSymbols());
}
catch ( DTSMException e ) {
throw new DBException(FaultCodes.COL_CANNOT_STORE, "Error storing object '" + key + "'", e);
}
col.setDocument(tx, key, dt);
}
/**
* setObject sets an XMLSerializable object in the Collection based on the
* provided Key. dbXML takes care of associating the implementation class
* with the XMLSerializable object.
*
* @param tx The controlling Transaction
* @param key The Key to use
* @param obj The Object to set
* @throws DBException If a Database Exception occurs
*/
public void setObject(Transaction tx, Object key, XMLSerializable obj) throws DBException {
putObject(tx, key, obj);
}
/**
* insertObject inserts an XMLSerializable object into the Collection and
* returns a newly generated Key. dbXML takes care of associating the
* implementation class with the XMLSerializable object.
*
* @param tx The controlling Transaction
* @param obj The Object to insert
* @return The new Object Identifier
* @throws DBException If a Database Exception occurs
*/
public Key insertObject(Transaction tx, XMLSerializable obj) throws DBException {
Key key = col.createNewOID();
putObject(tx, key, obj);
return key;
}
/**
* insertObject inserts an XMLSerializable object into the Collection based
* on the specified Key. dbXML takes care of associating the
* implementation class with the XMLSerializable object.
*
* @param tx The controlling Transaction
* @param key The Key to use
* @param obj The Object to insert
* @throws DBException If a Database Exception occurs
*/
public void insertObject(Transaction tx, Object key, XMLSerializable obj) throws DBException {
putObject(tx, key, obj);
}
/**
* getObject instantiates and returns an XMLSerializable object based on the
* provided Key. dbXML takes care of instantiating the correct class, but
* only if a class was registered with the Document in the first place.
*
* @param tx The controlling Transaction
* @param key The Document Key
* @return an Castable XMLSerializable Instance
* @throws DBException If a Database Exception occurs
*/
public XMLSerializable getObject(Transaction tx, Object key) throws DBException {
Document doc = null;
try {
DocumentTable dt = col.getDocument(tx, key);
if ( dt != null )
doc = DTSMHelper.tableToDocument(dt);
}
catch ( DTSMException e ) {
throw new DBException(FaultCodes.COL_CANNOT_RETRIEVE, "Error retrieving object '" + key + "'", e);
}
if ( doc != null ) {
String className = null;
NodeList childNodes = doc.getChildNodes();
int size = childNodes.getLength();
for ( int i = 0; i < size; i++ ) {
Node n = childNodes.item(i);
if ( n.getNodeType() == Node.PROCESSING_INSTRUCTION_NODE ) {
ProcessingInstruction pi = (ProcessingInstruction)n;
if ( pi.getTarget().equals(CLASSNAME) ) {
className = pi.getData().trim();
break;
}
}
}
if ( className != null ) {
try {
XMLSerializable obj = (XMLSerializable)ClassResolver.get(className).newInstance();
obj.streamFromXML(doc.getDocumentElement());
return obj;
}
catch ( Exception e ) {
e.printStackTrace(System.err);
}
}
}
return null;
}
}