/*
* Copyright (C) 2010 eXo Platform SAS.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.exoplatform.services.naming;
import org.exoplatform.commons.utils.PrivilegedFileHelper;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Stack;
import java.util.concurrent.ConcurrentHashMap;
import javax.naming.NameAlreadyBoundException;
import javax.naming.NamingException;
import javax.naming.Reference;
import javax.naming.StringRefAddr;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import javax.xml.stream.events.Attribute;
import javax.xml.stream.events.EndElement;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;
/**
* Class is responsible for binding references at runtime, persists on file and automatically binds after restart.
*
* @author <a href="anatoliy.bazko@exoplatform.org">Anatoliy Bazko</a>
* @version $Id: InitialContextBinder.java 111 2010-11-11 11:11:11Z tolusha $
*/
public class InitialContextBinder
{
public static final String BIND_REFERENCES_ELEMENT = "bind-references";
public static final String REFERENCE_ELEMENT = "reference";
public static final String PROPERTY_ELEMENT = "property";
public static final String REFADDR_ELEMENT = "ref-addr";
public static final String BIND_NAME_ATTR = "bind-name";
public static final String CLASS_NAME_ATTR = "class-name";
public static final String FACTORY_ATTR = "factory-name";
public static final String FACTORY_LOCATION_ATTR = "factory-location";
/**
* Initial context binder.
*/
protected final InitialContextInitializer initialContextInitializer;
/**
* Absolute file path to references's storage.
*/
protected final String bindingsStorePath;
/**
* All current binded references.
*/
protected Map<String, Reference> bindings;
/**
* InitialContextBinder constructor.
*
* @param initialContextInitializer
* initial context initializer
* @param initParams
* initialization parameters
* @throws FileNotFoundException
* @throws XMLStreamException
* @throws NamingException
*/
InitialContextBinder(InitialContextInitializer initialContextInitializer, String bindingsStorePath)
throws FileNotFoundException, XMLStreamException, NamingException
{
this.initialContextInitializer = initialContextInitializer;
this.bindings = new ConcurrentHashMap<String, Reference>();
this.bindingsStorePath = bindingsStorePath;
if (PrivilegedFileHelper.exists(new File(bindingsStorePath)))
{
Map<String, Reference> importedRefs = readBindings();
for (Entry<String, Reference> entry : importedRefs.entrySet())
{
bindInternally(entry.getKey(), entry.getValue());
}
}
}
/**
* InitialContextBinder constructor.
*/
InitialContextBinder(InitialContextInitializer initialContextInitializer) throws FileNotFoundException,
XMLStreamException, NamingException
{
this(initialContextInitializer, InitialContextInitializer.DEFAULT_BINDING_STORE_PATH);
}
/**
* Constructs references from params, binds in initial contexts and persists list of all binded
* references into file.
*
* @param bindName
* bind name
* @param className
* class name
* @param factory
* factory name
* @param factoryLocation
* factory location
* @param refAddr
* map of references's properties
*
* @throws NamingException
* if error occurs due to binding
* @throws XMLStreamException
* @throws FileNotFoundException
*/
public void bind(String bindName, String className, String factory, String factoryLocation,
Map<String, String> refAddr) throws NamingException, FileNotFoundException, XMLStreamException
{
Reference reference = new Reference(className, factory, factoryLocation);
for (Map.Entry<String, String> entry : refAddr.entrySet())
{
reference.add(new StringRefAddr(entry.getKey(), entry.getValue()));
}
bindInternally(bindName, reference);
saveBindings();
}
/**
* Binds the reference in initial contexts and persists list of all binded
* references into file.
*
* @param bindName
* bind name
* @param reference
* reference
* @throws NamingException
* if error occurs due to binding
* @throws FileNotFoundException
* @throws XMLStreamException
*/
public void bind(String bindName, Reference reference) throws NamingException, FileNotFoundException,
XMLStreamException
{
bindInternally(bindName, reference);
saveBindings();
}
/**
* Unbind the Reference with defined name, remove from the bindings list and persists the rest of references
* into the file.
*
* @param bindName
* the Reference's bind name
* @throws NamingException
* @throws FileNotFoundException
* @throws XMLStreamException
*/
public void unbind(String bindName) throws NamingException, FileNotFoundException,
XMLStreamException
{
initialContextInitializer.getInitialContext().unbind(bindName);
bindings.remove(bindName);
saveBindings();
}
/**
* Returns reference associated with defined name.
*
* @param bindName the name on which the reference was binded.
*/
public Reference getReference(String bindName)
{
return bindings.get(bindName);
}
private void bindInternally(String bindName, Reference reference) throws NamingException
{
try
{
initialContextInitializer.getInitialContext().bind(bindName, reference);
}
catch (NameAlreadyBoundException e)
{
initialContextInitializer.getInitialContext().rebind(bindName, reference);
}
bindings.put(bindName, reference);
}
/**
* Export references into xml-file.
*
* @throws XMLStreamException
* if any exception occurs during export
* @throws FileNotFoundException
* if can't open output stream from file
*/
protected synchronized void saveBindings() throws FileNotFoundException, XMLStreamException
{
XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();
XMLStreamWriter writer =
outputFactory.createXMLStreamWriter(PrivilegedFileHelper.fileOutputStream(bindingsStorePath), "UTF-8");
writer.writeStartDocument("UTF-8", "1.0");
writer.writeStartElement(BIND_REFERENCES_ELEMENT);
for (Entry<String, Reference> entry : bindings.entrySet())
{
String bindName = entry.getKey();
Reference reference = entry.getValue();
writer.writeStartElement(REFERENCE_ELEMENT);
writer.writeAttribute(BIND_NAME_ATTR, bindName);
if (reference.getClassName() != null)
{
writer.writeAttribute(CLASS_NAME_ATTR, reference.getClassName());
}
if (reference.getFactoryClassName() != null)
{
writer.writeAttribute(FACTORY_ATTR, reference.getFactoryClassName());
}
if (reference.getFactoryClassLocation() != null)
{
writer.writeAttribute(FACTORY_LOCATION_ATTR, reference.getFactoryClassLocation());
}
writer.writeStartElement(REFADDR_ELEMENT);
for (int i = 0; i < reference.size(); i++)
{
writer.writeStartElement(PROPERTY_ELEMENT);
writer.writeAttribute(reference.get(i).getType(), (String)reference.get(i).getContent());
writer.writeEndElement();
}
writer.writeEndElement();
writer.writeEndElement();
}
writer.writeEndElement();
writer.writeEndDocument();
}
/**
* Import references from xml-file.
*
* @return map with bind name - references
*
* @throws XMLStreamException
* if errors occurs during import
* @throws FileNotFoundException
* if can't open input stream from file
*/
protected Map<String, Reference> readBindings() throws FileNotFoundException, XMLStreamException
{
Stack<RefEntity> stack = new Stack<RefEntity>();
Map<String, Reference> importedRefs = new HashMap<String, Reference>();
XMLInputFactory factory = XMLInputFactory.newInstance();
XMLEventReader reader =
factory.createXMLEventReader(PrivilegedFileHelper.fileInputStream(bindingsStorePath), "UTF-8");
while (reader.hasNext())
{
XMLEvent event = reader.nextEvent();
switch (event.getEventType())
{
case XMLStreamConstants.START_ELEMENT :
StartElement startElement = event.asStartElement();
Map<String, String> attr = new HashMap<String, String>();
Iterator attributes = startElement.getAttributes();
while (attributes.hasNext())
{
Attribute attribute = (Attribute)attributes.next();
attr.put(attribute.getName().getLocalPart(), attribute.getValue());
}
String localName = startElement.getName().getLocalPart();
if (localName.equals(REFERENCE_ELEMENT))
{
String bindName = attr.get(BIND_NAME_ATTR);
String className = attr.get(CLASS_NAME_ATTR);
String factoryName = attr.get(FACTORY_ATTR);
String factoryLocation = attr.get(FACTORY_LOCATION_ATTR);
Reference reference = new Reference(className, factoryName, factoryLocation);
stack.push(new RefEntity(bindName, reference));
}
else if (localName.equals(PROPERTY_ELEMENT))
{
RefEntity refEntity = stack.pop();
Reference reference = refEntity.getValue();
for (Entry<String, String> entry : attr.entrySet())
{
reference.add(new StringRefAddr(entry.getKey(), entry.getValue()));
}
refEntity.setValue(reference);
stack.push(refEntity);
}
break;
case XMLStreamConstants.END_ELEMENT :
EndElement endElement = event.asEndElement();
localName = endElement.getName().getLocalPart();
if (localName.equals(REFERENCE_ELEMENT))
{
RefEntity refEntity = stack.pop();
importedRefs.put(refEntity.getKey(), refEntity.getValue());
}
break;
default :
break;
}
}
return importedRefs;
}
/**
* Class implements Map.Entry interface and used to push/pop entity in stack.
*/
class RefEntity implements Map.Entry<String, Reference>
{
/**
* Entry key.
*/
private final String key;
/**
* Entry value.
*/
private Reference value;
/**
* RefEntity constructor.
*
* @param key
* entry key
* @param value
* entry value
*/
public RefEntity(String key, Reference value)
{
this.key = key;
this.value = value;
}
/**
* {@inheritDoc}
*/
public String getKey()
{
return key;
}
/**
* {@inheritDoc}
*/
public Reference getValue()
{
return value;
}
/**
* {@inheritDoc}
*/
public Reference setValue(Reference value)
{
Reference oldValue = this.value;
this.value = value;
return oldValue;
}
}
}