/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.naming;

import java.util.Enumeration;
import java.util.HashMap;
import java.util.Hashtable;

import javax.naming.Binding;
import javax.naming.CompositeName;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.LinkRef;
import javax.naming.Name;
import javax.naming.NameAlreadyBoundException;
import javax.naming.NameClassPair;
import javax.naming.NameNotFoundException;
import javax.naming.NameParser;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.NotContextException;
import javax.naming.OperationNotSupportedException;
import javax.naming.Reference;
import javax.naming.Referenceable;
import javax.naming.spi.NamingManager;

/**
 * Catalina JNDI Context implementation.
 *
 * @author Remy Maucherat
 */
public class NamingContext implements Context {

	// -------------------------------------------------------------- Constants

	/**
	 * Name parser for this context.
	 */
	protected static final NameParser nameParser = new NameParserImpl();

	private static final org.apache.juli.logging.Log log = org.apache.juli.logging.LogFactory
			.getLog(NamingContext.class);

	// ----------------------------------------------------------- Constructors

	/**
	 * Builds a naming context.
	 *
	 * @param env
	 *            The environment to use to construct the naming context
	 * @param name
	 *            The name of the associated Catalina Context
	 */
	public NamingContext(Hashtable<String, Object> env, String name) throws NamingException {
		this.bindings = new HashMap<String, NamingEntry>();
		this.env = new Hashtable<String, Object>();
		this.name = name;
		// Populating the environment hashtable
		if (env != null) {
			Enumeration<String> envEntries = env.keys();
			while (envEntries.hasMoreElements()) {
				String entryName = envEntries.nextElement();
				addToEnvironment(entryName, env.get(entryName));
			}
		}
	}

	/**
	 * Builds a naming context.
	 *
	 * @param env
	 *            The environment to use to construct the naming context
	 * @param name
	 *            The name of the associated Catalina Context
	 * @param bindings
	 *            The initial bindings for the naming context
	 */
	public NamingContext(Hashtable<String, Object> env, String name, HashMap<String, NamingEntry> bindings)
			throws NamingException {
		this(env, name);
		this.bindings = bindings;
	}

	// ----------------------------------------------------- Instance Variables

	/**
	 * Environment.
	 */
	protected Hashtable<String, Object> env;

	/**
	 * The string manager for this package.
	 */
	protected static final StringManager sm = StringManager.getManager(Constants.Package);

	/**
	 * Bindings in this Context.
	 */
	protected HashMap<String, NamingEntry> bindings;

	/**
	 * Name of the associated Catalina Context.
	 */
	protected String name;

	/**
	 * Determines if an attempt to write to a read-only context results in an
	 * exception or if the request is ignored.
	 */
	private boolean exceptionOnFailedWrite = true;

	public boolean getExceptionOnFailedWrite() {
		return exceptionOnFailedWrite;
	}

	public void setExceptionOnFailedWrite(boolean exceptionOnFailedWrite) {
		this.exceptionOnFailedWrite = exceptionOnFailedWrite;
	}

	// -------------------------------------------------------- Context Methods

	/**
	 * Retrieves the named object. If name is empty, returns a new instance of
	 * this context (which represents the same naming context as this context,
	 * but its environment may be modified independently and it may be accessed
	 * concurrently).
	 * 
	 * @param name
	 *            the name of the object to look up
	 * @return the object bound to name
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Object lookup(Name name) throws NamingException {
		return lookup(name, true);
	}

	/**
	 * Retrieves the named object.
	 * 
	 * @param name
	 *            the name of the object to look up
	 * @return the object bound to name
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Object lookup(String name) throws NamingException {
		return lookup(new CompositeName(name), true);
	}

	/**
	 * Binds a name to an object. All intermediate contexts and the target
	 * context (that named by all but terminal atomic component of the name)
	 * must already exist.
	 * 
	 * @param name
	 *            the name to bind; may not be empty
	 * @param obj
	 *            the object to bind; possibly null
	 * @exception NameAlreadyBoundException
	 *                if name is already bound
	 * @exception javax.naming.directory.InvalidAttributesException
	 *                if object did not supply all mandatory attributes
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public void bind(Name name, Object obj) throws NamingException {
		bind(name, obj, false);
	}

	/**
	 * Binds a name to an object.
	 * 
	 * @param name
	 *            the name to bind; may not be empty
	 * @param obj
	 *            the object to bind; possibly null
	 * @exception NameAlreadyBoundException
	 *                if name is already bound
	 * @exception javax.naming.directory.InvalidAttributesException
	 *                if object did not supply all mandatory attributes
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public void bind(String name, Object obj) throws NamingException {
		bind(new CompositeName(name), obj);
	}

	/**
	 * Binds a name to an object, overwriting any existing binding. All
	 * intermediate contexts and the target context (that named by all but
	 * terminal atomic component of the name) must already exist.
	 * <p>
	 * If the object is a DirContext, any existing attributes associated with
	 * the name are replaced with those of the object. Otherwise, any existing
	 * attributes associated with the name remain unchanged.
	 * 
	 * @param name
	 *            the name to bind; may not be empty
	 * @param obj
	 *            the object to bind; possibly null
	 * @exception javax.naming.directory.InvalidAttributesException
	 *                if object did not supply all mandatory attributes
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public void rebind(Name name, Object obj) throws NamingException {
		bind(name, obj, true);
	}

	/**
	 * Binds a name to an object, overwriting any existing binding.
	 * 
	 * @param name
	 *            the name to bind; may not be empty
	 * @param obj
	 *            the object to bind; possibly null
	 * @exception javax.naming.directory.InvalidAttributesException
	 *                if object did not supply all mandatory attributes
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public void rebind(String name, Object obj) throws NamingException {
		rebind(new CompositeName(name), obj);
	}

	/**
	 * Unbinds the named object. Removes the terminal atomic name in name from
	 * the target context--that named by all but the terminal atomic part of
	 * name.
	 * <p>
	 * This method is idempotent. It succeeds even if the terminal atomic name
	 * is not bound in the target context, but throws NameNotFoundException if
	 * any of the intermediate contexts do not exist.
	 * 
	 * @param name
	 *            the name to bind; may not be empty
	 * @exception NameNotFoundException
	 *                if an intermediate context does not exist
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public void unbind(Name name) throws NamingException {

		if (!checkWritable()) {
			return;
		}

		while ((!name.isEmpty()) && (name.get(0).length() == 0))
			name = name.getSuffix(1);
		if (name.isEmpty())
			throw new NamingException(sm.getString("namingContext.invalidName"));

		NamingEntry entry = bindings.get(name.get(0));

		if (entry == null) {
			throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name, name.get(0)));
		}

		if (name.size() > 1) {
			if (entry.type == NamingEntry.CONTEXT) {
				((Context) entry.value).unbind(name.getSuffix(1));
			} else {
				throw new NamingException(sm.getString("namingContext.contextExpected"));
			}
		} else {
			bindings.remove(name.get(0));
		}

	}

	/**
	 * Unbinds the named object.
	 * 
	 * @param name
	 *            the name to bind; may not be empty
	 * @exception NameNotFoundException
	 *                if an intermediate context does not exist
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public void unbind(String name) throws NamingException {
		unbind(new CompositeName(name));
	}

	/**
	 * Binds a new name to the object bound to an old name, and unbinds the old
	 * name. Both names are relative to this context. Any attributes associated
	 * with the old name become associated with the new name. Intermediate
	 * contexts of the old name are not changed.
	 * 
	 * @param oldName
	 *            the name of the existing binding; may not be empty
	 * @param newName
	 *            the name of the new binding; may not be empty
	 * @exception NameAlreadyBoundException
	 *                if newName is already bound
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public void rename(Name oldName, Name newName) throws NamingException {
		Object value = lookup(oldName);
		bind(newName, value);
		unbind(oldName);
	}

	/**
	 * Binds a new name to the object bound to an old name, and unbinds the old
	 * name.
	 * 
	 * @param oldName
	 *            the name of the existing binding; may not be empty
	 * @param newName
	 *            the name of the new binding; may not be empty
	 * @exception NameAlreadyBoundException
	 *                if newName is already bound
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public void rename(String oldName, String newName) throws NamingException {
		rename(new CompositeName(oldName), new CompositeName(newName));
	}

	/**
	 * Enumerates the names bound in the named context, along with the class
	 * names of objects bound to them. The contents of any subcontexts are not
	 * included.
	 * <p>
	 * If a binding is added to or removed from this context, its effect on an
	 * enumeration previously returned is undefined.
	 * 
	 * @param name
	 *            the name of the context to list
	 * @return an enumeration of the names and class names of the bindings in
	 *         this context. Each element of the enumeration is of type
	 *         NameClassPair.
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public NamingEnumeration<NameClassPair> list(Name name) throws NamingException {
		// Removing empty parts
		while ((!name.isEmpty()) && (name.get(0).length() == 0))
			name = name.getSuffix(1);
		if (name.isEmpty()) {
			return new NamingContextEnumeration(bindings.values().iterator());
		}

		NamingEntry entry = bindings.get(name.get(0));

		if (entry == null) {
			throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name, name.get(0)));
		}

		if (entry.type != NamingEntry.CONTEXT) {
			throw new NamingException(sm.getString("namingContext.contextExpected"));
		}
		return ((Context) entry.value).list(name.getSuffix(1));
	}

	/**
	 * Enumerates the names bound in the named context, along with the class
	 * names of objects bound to them.
	 * 
	 * @param name
	 *            the name of the context to list
	 * @return an enumeration of the names and class names of the bindings in
	 *         this context. Each element of the enumeration is of type
	 *         NameClassPair.
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public NamingEnumeration<NameClassPair> list(String name) throws NamingException {
		return list(new CompositeName(name));
	}

	/**
	 * Enumerates the names bound in the named context, along with the objects
	 * bound to them. The contents of any subcontexts are not included.
	 * <p>
	 * If a binding is added to or removed from this context, its effect on an
	 * enumeration previously returned is undefined.
	 * 
	 * @param name
	 *            the name of the context to list
	 * @return an enumeration of the bindings in this context. Each element of
	 *         the enumeration is of type Binding.
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public NamingEnumeration<Binding> listBindings(Name name) throws NamingException {
		// Removing empty parts
		while ((!name.isEmpty()) && (name.get(0).length() == 0))
			name = name.getSuffix(1);
		if (name.isEmpty()) {
			return new NamingContextBindingsEnumeration(bindings.values().iterator(), this);
		}

		NamingEntry entry = bindings.get(name.get(0));

		if (entry == null) {
			throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name, name.get(0)));
		}

		if (entry.type != NamingEntry.CONTEXT) {
			throw new NamingException(sm.getString("namingContext.contextExpected"));
		}
		return ((Context) entry.value).listBindings(name.getSuffix(1));
	}

	/**
	 * Enumerates the names bound in the named context, along with the objects
	 * bound to them.
	 * 
	 * @param name
	 *            the name of the context to list
	 * @return an enumeration of the bindings in this context. Each element of
	 *         the enumeration is of type Binding.
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public NamingEnumeration<Binding> listBindings(String name) throws NamingException {
		return listBindings(new CompositeName(name));
	}

	/**
	 * Destroys the named context and removes it from the namespace. Any
	 * attributes associated with the name are also removed. Intermediate
	 * contexts are not destroyed.
	 * <p>
	 * This method is idempotent. It succeeds even if the terminal atomic name
	 * is not bound in the target context, but throws NameNotFoundException if
	 * any of the intermediate contexts do not exist.
	 * 
	 * In a federated naming system, a context from one naming system may be
	 * bound to a name in another. One can subsequently look up and perform
	 * operations on the foreign context using a composite name. However, an
	 * attempt destroy the context using this composite name will fail with
	 * NotContextException, because the foreign context is not a "subcontext" of
	 * the context in which it is bound. Instead, use unbind() to remove the
	 * binding of the foreign context. Destroying the foreign context requires
	 * that the destroySubcontext() be performed on a context from the foreign
	 * context's "native" naming system.
	 * 
	 * @param name
	 *            the name of the context to be destroyed; may not be empty
	 * @exception NameNotFoundException
	 *                if an intermediate context does not exist
	 * @exception NotContextException
	 *                if the name is bound but does not name a context, or does
	 *                not name a context of the appropriate type
	 */
	@Override
	public void destroySubcontext(Name name) throws NamingException {

		if (!checkWritable()) {
			return;
		}

		while ((!name.isEmpty()) && (name.get(0).length() == 0))
			name = name.getSuffix(1);
		if (name.isEmpty())
			throw new NamingException(sm.getString("namingContext.invalidName"));

		NamingEntry entry = bindings.get(name.get(0));

		if (entry == null) {
			throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name, name.get(0)));
		}

		if (name.size() > 1) {
			if (entry.type == NamingEntry.CONTEXT) {
				((Context) entry.value).destroySubcontext(name.getSuffix(1));
			} else {
				throw new NamingException(sm.getString("namingContext.contextExpected"));
			}
		} else {
			if (entry.type == NamingEntry.CONTEXT) {
				((Context) entry.value).close();
				bindings.remove(name.get(0));
			} else {
				throw new NotContextException(sm.getString("namingContext.contextExpected"));
			}
		}

	}

	/**
	 * Destroys the named context and removes it from the namespace.
	 * 
	 * @param name
	 *            the name of the context to be destroyed; may not be empty
	 * @exception NameNotFoundException
	 *                if an intermediate context does not exist
	 * @exception NotContextException
	 *                if the name is bound but does not name a context, or does
	 *                not name a context of the appropriate type
	 */
	@Override
	public void destroySubcontext(String name) throws NamingException {
		destroySubcontext(new CompositeName(name));
	}

	/**
	 * Creates and binds a new context. Creates a new context with the given
	 * name and binds it in the target context (that named by all but terminal
	 * atomic component of the name). All intermediate contexts and the target
	 * context must already exist.
	 * 
	 * @param name
	 *            the name of the context to create; may not be empty
	 * @return the newly created context
	 * @exception NameAlreadyBoundException
	 *                if name is already bound
	 * @exception javax.naming.directory.InvalidAttributesException
	 *                if creation of the sub-context requires specification of
	 *                mandatory attributes
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Context createSubcontext(Name name) throws NamingException {
		if (!checkWritable()) {
			return null;
		}

		NamingContext newContext = new NamingContext(env, this.name);
		bind(name, newContext);

		newContext.setExceptionOnFailedWrite(getExceptionOnFailedWrite());

		return newContext;
	}

	/**
	 * Creates and binds a new context.
	 * 
	 * @param name
	 *            the name of the context to create; may not be empty
	 * @return the newly created context
	 * @exception NameAlreadyBoundException
	 *                if name is already bound
	 * @exception javax.naming.directory.InvalidAttributesException
	 *                if creation of the sub-context requires specification of
	 *                mandatory attributes
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Context createSubcontext(String name) throws NamingException {
		return createSubcontext(new CompositeName(name));
	}

	/**
	 * Retrieves the named object, following links except for the terminal
	 * atomic component of the name. If the object bound to name is not a link,
	 * returns the object itself.
	 * 
	 * @param name
	 *            the name of the object to look up
	 * @return the object bound to name, not following the terminal link (if
	 *         any).
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Object lookupLink(Name name) throws NamingException {
		return lookup(name, false);
	}

	/**
	 * Retrieves the named object, following links except for the terminal
	 * atomic component of the name.
	 * 
	 * @param name
	 *            the name of the object to look up
	 * @return the object bound to name, not following the terminal link (if
	 *         any).
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Object lookupLink(String name) throws NamingException {
		return lookup(new CompositeName(name), false);
	}

	/**
	 * Retrieves the parser associated with the named context. In a federation
	 * of namespaces, different naming systems will parse names differently.
	 * This method allows an application to get a parser for parsing names into
	 * their atomic components using the naming convention of a particular
	 * naming system. Within any single naming system, NameParser objects
	 * returned by this method must be equal (using the equals() test).
	 * 
	 * @param name
	 *            the name of the context from which to get the parser
	 * @return a name parser that can parse compound names into their atomic
	 *         components
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public NameParser getNameParser(Name name) throws NamingException {

		while ((!name.isEmpty()) && (name.get(0).length() == 0))
			name = name.getSuffix(1);
		if (name.isEmpty())
			return nameParser;

		if (name.size() > 1) {
			Object obj = bindings.get(name.get(0));
			if (obj instanceof Context) {
				return ((Context) obj).getNameParser(name.getSuffix(1));
			} else {
				throw new NotContextException(sm.getString("namingContext.contextExpected"));
			}
		}

		return nameParser;

	}

	/**
	 * Retrieves the parser associated with the named context.
	 * 
	 * @param name
	 *            the name of the context from which to get the parser
	 * @return a name parser that can parse compound names into their atomic
	 *         components
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public NameParser getNameParser(String name) throws NamingException {
		return getNameParser(new CompositeName(name));
	}

	/**
	 * Composes the name of this context with a name relative to this context.
	 * <p>
	 * Given a name (name) relative to this context, and the name (prefix) of
	 * this context relative to one of its ancestors, this method returns the
	 * composition of the two names using the syntax appropriate for the naming
	 * system(s) involved. That is, if name names an object relative to this
	 * context, the result is the name of the same object, but relative to the
	 * ancestor context. None of the names may be null.
	 * 
	 * @param name
	 *            a name relative to this context
	 * @param prefix
	 *            the name of this context relative to one of its ancestors
	 * @return the composition of prefix and name
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Name composeName(Name name, Name prefix) throws NamingException {
		prefix = (Name) prefix.clone();
		return prefix.addAll(name);
	}

	/**
	 * Composes the name of this context with a name relative to this context.
	 * 
	 * @param name
	 *            a name relative to this context
	 * @param prefix
	 *            the name of this context relative to one of its ancestors
	 * @return the composition of prefix and name
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public String composeName(String name, String prefix) throws NamingException {
		return prefix + "/" + name;
	}

	/**
	 * Adds a new environment property to the environment of this context. If
	 * the property already exists, its value is overwritten.
	 * 
	 * @param propName
	 *            the name of the environment property to add; may not be null
	 * @param propVal
	 *            the value of the property to add; may not be null
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Object addToEnvironment(String propName, Object propVal) throws NamingException {
		return env.put(propName, propVal);
	}

	/**
	 * Removes an environment property from the environment of this context.
	 * 
	 * @param propName
	 *            the name of the environment property to remove; may not be
	 *            null
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Object removeFromEnvironment(String propName) throws NamingException {
		return env.remove(propName);
	}

	/**
	 * Retrieves the environment in effect for this context. See class
	 * description for more details on environment properties. The caller should
	 * not make any changes to the object returned: their effect on the context
	 * is undefined. The environment of this context may be changed using
	 * addToEnvironment() and removeFromEnvironment().
	 * 
	 * @return the environment of this context; never null
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public Hashtable<?, ?> getEnvironment() throws NamingException {
		return env;
	}

	/**
	 * Closes this context. This method releases this context's resources
	 * immediately, instead of waiting for them to be released automatically by
	 * the garbage collector. This method is idempotent: invoking it on a
	 * context that has already been closed has no effect. Invoking any other
	 * method on a closed context is not allowed, and results in undefined
	 * behaviour.
	 * 
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public void close() throws NamingException {
		if (!checkWritable()) {
			return;
		}
		env.clear();
	}

	/**
	 * Retrieves the full name of this context within its own namespace.
	 * <p>
	 * Many naming services have a notion of a "full name" for objects in their
	 * respective namespaces. For example, an LDAP entry has a distinguished
	 * name, and a DNS record has a fully qualified name. This method allows the
	 * client application to retrieve this name. The string returned by this
	 * method is not a JNDI composite name and should not be passed directly to
	 * context methods. In naming systems for which the notion of full name does
	 * not make sense, OperationNotSupportedException is thrown.
	 * 
	 * @return this context's name in its own namespace; never null
	 * @exception OperationNotSupportedException
	 *                if the naming system does not have the notion of a full
	 *                name
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	@Override
	public String getNameInNamespace() throws NamingException {
		throw new OperationNotSupportedException(sm.getString("namingContext.noAbsoluteName"));
		// FIXME ?
	}

	// ------------------------------------------------------ Protected Methods

	/**
	 * Retrieves the named object.
	 * 
	 * @param name
	 *            the name of the object to look up
	 * @param resolveLinks
	 *            If true, the links will be resolved
	 * @return the object bound to name
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	protected Object lookup(Name name, boolean resolveLinks) throws NamingException {

		// Removing empty parts
		while ((!name.isEmpty()) && (name.get(0).length() == 0))
			name = name.getSuffix(1);
		if (name.isEmpty()) {
			// If name is empty, a newly allocated naming context is returned
			return new NamingContext(env, this.name, bindings);
		}

		NamingEntry entry = bindings.get(name.get(0));

		if (entry == null) {
			throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name, name.get(0)));
		}

		if (name.size() > 1) {
			// If the size of the name is greater that 1, then we go through a
			// number of subcontexts.
			if (entry.type != NamingEntry.CONTEXT) {
				throw new NamingException(sm.getString("namingContext.contextExpected"));
			}
			return ((Context) entry.value).lookup(name.getSuffix(1));
		} else {
			if ((resolveLinks) && (entry.type == NamingEntry.LINK_REF)) {
				String link = ((LinkRef) entry.value).getLinkName();
				if (link.startsWith(".")) {
					// Link relative to this context
					return lookup(link.substring(1));
				} else {
					return (new InitialContext(env)).lookup(link);
				}
			} else if (entry.type == NamingEntry.REFERENCE) {
				try {
					Object obj = NamingManager.getObjectInstance(entry.value, name, this, env);
					if (entry.value instanceof ResourceRef) {
						boolean singleton = Boolean
								.parseBoolean((String) ((ResourceRef) entry.value).get("singleton").getContent());
						if (singleton) {
							entry.type = NamingEntry.ENTRY;
							entry.value = obj;
						}
					}
					return obj;
				} catch (NamingException e) {
					throw e;
				} catch (Exception e) {
					log.warn(sm.getString("namingContext.failResolvingReference"), e);
					throw new NamingException(e.getMessage());
				}
			} else {
				return entry.value;
			}
		}

	}

	/**
	 * Binds a name to an object. All intermediate contexts and the target
	 * context (that named by all but terminal atomic component of the name)
	 * must already exist.
	 * 
	 * @param name
	 *            the name to bind; may not be empty
	 * @param obj
	 *            the object to bind; possibly null
	 * @param rebind
	 *            if true, then perform a rebind (ie, overwrite)
	 * @exception NameAlreadyBoundException
	 *                if name is already bound
	 * @exception javax.naming.directory.InvalidAttributesException
	 *                if object did not supply all mandatory attributes
	 * @exception NamingException
	 *                if a naming exception is encountered
	 */
	protected void bind(Name name, Object obj, boolean rebind) throws NamingException {

		if (!checkWritable()) {
			return;
		}

		while ((!name.isEmpty()) && (name.get(0).length() == 0))
			name = name.getSuffix(1);
		if (name.isEmpty())
			throw new NamingException(sm.getString("namingContext.invalidName"));

		NamingEntry entry = bindings.get(name.get(0));

		if (name.size() > 1) {
			if (entry == null) {
				throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name, name.get(0)));
			}
			if (entry.type == NamingEntry.CONTEXT) {
				if (rebind) {
					((Context) entry.value).rebind(name.getSuffix(1), obj);
				} else {
					((Context) entry.value).bind(name.getSuffix(1), obj);
				}
			} else {
				throw new NamingException(sm.getString("namingContext.contextExpected"));
			}
		} else {
			if ((!rebind) && (entry != null)) {
				throw new NameAlreadyBoundException(sm.getString("namingContext.alreadyBound", name.get(0)));
			} else {
				// Getting the type of the object and wrapping it within a new
				// NamingEntry
				Object toBind = NamingManager.getStateToBind(obj, name, this, env);
				if (toBind instanceof Context) {
					entry = new NamingEntry(name.get(0), toBind, NamingEntry.CONTEXT);
				} else if (toBind instanceof LinkRef) {
					entry = new NamingEntry(name.get(0), toBind, NamingEntry.LINK_REF);
				} else if (toBind instanceof Reference) {
					entry = new NamingEntry(name.get(0), toBind, NamingEntry.REFERENCE);
				} else if (toBind instanceof Referenceable) {
					toBind = ((Referenceable) toBind).getReference();
					entry = new NamingEntry(name.get(0), toBind, NamingEntry.REFERENCE);
				} else {
					entry = new NamingEntry(name.get(0), toBind, NamingEntry.ENTRY);
				}
				bindings.put(name.get(0), entry);
			}
		}

	}

	/**
	 * Returns true if writing is allowed on this context.
	 */
	protected boolean isWritable() {
		return ContextAccessController.isWritable(name);
	}

	/**
	 * Throws a naming exception is Context is not writable.
	 */
	protected boolean checkWritable() throws NamingException {
		if (isWritable()) {
			return true;
		} else {
			if (exceptionOnFailedWrite) {
				throw new javax.naming.OperationNotSupportedException(sm.getString("namingContext.readOnly"));
			}
		}
		return false;
	}
}