/*
*
* 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.qpid.amqp_1_0.jms.jndi;
import java.io.Serializable;
import java.util.Collections;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Map;
import javax.naming.Binding;
import javax.naming.CompositeName;
import javax.naming.Context;
import javax.naming.LinkRef;
import javax.naming.Name;
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.spi.NamingManager;
/**
* Based on class from ActiveMQ.
* A read-only Context
* <p/>
* This version assumes it and all its subcontext are read-only and any attempt
* to modify (e.g. through bind) will result in an OperationNotSupportedException.
* Each Context in the tree builds a cache of the entries in all sub-contexts
* to optimise the performance of lookup.
* </p>
* <p>This implementation is intended to optimise the performance of lookup(String)
* to about the level of a HashMap get. It has been observed that the scheme
* resolution phase performed by the JVM takes considerably longer, so for
* optimum performance lookups should be coded like:</p>
* <code>
* Context componentContext = (Context)new InitialContext().lookup("java:comp");
* String envEntry = (String) componentContext.lookup("env/myEntry");
* String envEntry2 = (String) componentContext.lookup("env/myEntry2");
* </code>
*/
public class ReadOnlyContext implements Context, Serializable
{
private static final long serialVersionUID = -5754338187296859149L;
protected static final NameParser nameParser = new NameParserImpl();
protected final Hashtable environment; // environment for this context
protected final Map bindings; // bindings at my level
protected final Map treeBindings; // all bindings under me
private boolean frozen = false;
private String nameInNamespace = "";
public static final String SEPARATOR = "/";
public ReadOnlyContext()
{
environment = new Hashtable();
bindings = new HashMap();
treeBindings = new HashMap();
}
public ReadOnlyContext(Hashtable env)
{
if (env == null)
{
this.environment = new Hashtable();
}
else
{
this.environment = new Hashtable(env);
}
this.bindings = Collections.EMPTY_MAP;
this.treeBindings = Collections.EMPTY_MAP;
}
public ReadOnlyContext(Hashtable environment, Map bindings)
{
if (environment == null)
{
this.environment = new Hashtable();
}
else
{
this.environment = new Hashtable(environment);
}
this.bindings = bindings;
treeBindings = new HashMap();
frozen = true;
}
public ReadOnlyContext(Hashtable environment, Map bindings, String nameInNamespace)
{
this(environment, bindings);
this.nameInNamespace = nameInNamespace;
}
protected ReadOnlyContext(ReadOnlyContext clone, Hashtable env)
{
this.bindings = clone.bindings;
this.treeBindings = clone.treeBindings;
this.environment = new Hashtable(env);
}
protected ReadOnlyContext(ReadOnlyContext clone, Hashtable env, String nameInNamespace)
{
this(clone, env);
this.nameInNamespace = nameInNamespace;
}
public void freeze()
{
frozen = true;
}
boolean isFrozen()
{
return frozen;
}
/**
* internalBind is intended for use only during setup or possibly by suitably synchronized superclasses.
* It binds every possible lookup into a map in each context. To do this, each context
* strips off one name segment and if necessary creates a new context for it. Then it asks that context
* to bind the remaining name. It returns a map containing all the bindings from the next context, plus
* the context it just created (if it in fact created it). (the names are suitably extended by the segment
* originally lopped off).
*
* @param name
* @param value
* @return
* @throws javax.naming.NamingException
*/
protected Map internalBind(String name, Object value) throws NamingException
{
assert (name != null) && (name.length() > 0);
assert !frozen;
Map newBindings = new HashMap();
int pos = name.indexOf('/');
if (pos == -1)
{
if (treeBindings.put(name, value) != null)
{
throw new NamingException("Something already bound at " + name);
}
bindings.put(name, value);
newBindings.put(name, value);
}
else
{
String segment = name.substring(0, pos);
assert segment != null;
assert !segment.equals("");
Object o = treeBindings.get(segment);
if (o == null)
{
o = newContext();
treeBindings.put(segment, o);
bindings.put(segment, o);
newBindings.put(segment, o);
}
else if (!(o instanceof ReadOnlyContext))
{
throw new NamingException("Something already bound where a subcontext should go");
}
ReadOnlyContext readOnlyContext = (ReadOnlyContext) o;
String remainder = name.substring(pos + 1);
Map subBindings = readOnlyContext.internalBind(remainder, value);
for (Iterator iterator = subBindings.entrySet().iterator(); iterator.hasNext();)
{
Map.Entry entry = (Map.Entry) iterator.next();
String subName = segment + "/" + (String) entry.getKey();
Object bound = entry.getValue();
treeBindings.put(subName, bound);
newBindings.put(subName, bound);
}
}
return newBindings;
}
protected ReadOnlyContext newContext()
{
return new ReadOnlyContext();
}
public Object addToEnvironment(String propName, Object propVal) throws NamingException
{
return environment.put(propName, propVal);
}
public Hashtable getEnvironment() throws NamingException
{
return (Hashtable) environment.clone();
}
public Object removeFromEnvironment(String propName) throws NamingException
{
return environment.remove(propName);
}
public Object lookup(String name) throws NamingException
{
if (name.length() == 0)
{
return this;
}
Object result = treeBindings.get(name);
if (result == null)
{
result = bindings.get(name);
}
if (result == null)
{
int pos = name.indexOf(':');
if (pos > 0)
{
String scheme = name.substring(0, pos);
Context ctx = NamingManager.getURLContext(scheme, environment);
if (ctx == null)
{
throw new NamingException("scheme " + scheme + " not recognized");
}
return ctx.lookup(name);
}
else
{
// Split out the first name of the path
// and look for it in the bindings map.
CompositeName path = new CompositeName(name);
if (path.size() == 0)
{
return this;
}
else
{
String first = path.get(0);
Object obj = bindings.get(first);
if (obj == null)
{
throw new NameNotFoundException(name);
}
else if ((obj instanceof Context) && (path.size() > 1))
{
Context subContext = (Context) obj;
obj = subContext.lookup(path.getSuffix(1));
}
return obj;
}
}
}
if (result instanceof LinkRef)
{
LinkRef ref = (LinkRef) result;
result = lookup(ref.getLinkName());
}
if (result instanceof Reference)
{
try
{
result = NamingManager.getObjectInstance(result, null, null, this.environment);
}
catch (NamingException e)
{
throw e;
}
catch (Exception e)
{
throw (NamingException) new NamingException("could not look up : " + name).initCause(e);
}
}
if (result instanceof ReadOnlyContext)
{
String prefix = getNameInNamespace();
if (prefix.length() > 0)
{
prefix = prefix + SEPARATOR;
}
result = new ReadOnlyContext((ReadOnlyContext) result, environment, prefix + name);
}
return result;
}
public Object lookup(Name name) throws NamingException
{
return lookup(name.toString());
}
public Object lookupLink(String name) throws NamingException
{
return lookup(name);
}
public Name composeName(Name name, Name prefix) throws NamingException
{
Name result = (Name) prefix.clone();
result.addAll(name);
return result;
}
public String composeName(String name, String prefix) throws NamingException
{
CompositeName result = new CompositeName(prefix);
result.addAll(new CompositeName(name));
return result.toString();
}
public NamingEnumeration list(String name) throws NamingException
{
Object o = lookup(name);
if (o == this)
{
return new ListEnumeration();
}
else if (o instanceof Context)
{
return ((Context) o).list("");
}
else
{
throw new NotContextException();
}
}
public NamingEnumeration listBindings(String name) throws NamingException
{
Object o = lookup(name);
if (o == this)
{
return new ListBindingEnumeration();
}
else if (o instanceof Context)
{
return ((Context) o).listBindings("");
}
else
{
throw new NotContextException();
}
}
public Object lookupLink(Name name) throws NamingException
{
return lookupLink(name.toString());
}
public NamingEnumeration list(Name name) throws NamingException
{
return list(name.toString());
}
public NamingEnumeration listBindings(Name name) throws NamingException
{
return listBindings(name.toString());
}
public void bind(Name name, Object obj) throws NamingException
{
throw new OperationNotSupportedException();
}
public void bind(String name, Object obj) throws NamingException
{
throw new OperationNotSupportedException();
}
public void close() throws NamingException
{
// ignore
}
public Context createSubcontext(Name name) throws NamingException
{
throw new OperationNotSupportedException();
}
public Context createSubcontext(String name) throws NamingException
{
throw new OperationNotSupportedException();
}
public void destroySubcontext(Name name) throws NamingException
{
throw new OperationNotSupportedException();
}
public void destroySubcontext(String name) throws NamingException
{
throw new OperationNotSupportedException();
}
public String getNameInNamespace() throws NamingException
{
return nameInNamespace;
}
public NameParser getNameParser(Name name) throws NamingException
{
return nameParser;
}
public NameParser getNameParser(String name) throws NamingException
{
return nameParser;
}
public void rebind(Name name, Object obj) throws NamingException
{
throw new OperationNotSupportedException();
}
public void rebind(String name, Object obj) throws NamingException
{
throw new OperationNotSupportedException();
}
public void rename(Name oldName, Name newName) throws NamingException
{
throw new OperationNotSupportedException();
}
public void rename(String oldName, String newName) throws NamingException
{
throw new OperationNotSupportedException();
}
public void unbind(Name name) throws NamingException
{
throw new OperationNotSupportedException();
}
public void unbind(String name) throws NamingException
{
throw new OperationNotSupportedException();
}
private abstract class LocalNamingEnumeration implements NamingEnumeration
{
private Iterator i = bindings.entrySet().iterator();
public boolean hasMore() throws NamingException
{
return i.hasNext();
}
public boolean hasMoreElements()
{
return i.hasNext();
}
protected Map.Entry getNext()
{
return (Map.Entry) i.next();
}
public void close() throws NamingException
{ }
}
private class ListEnumeration extends LocalNamingEnumeration
{
public Object next() throws NamingException
{
return nextElement();
}
public Object nextElement()
{
Map.Entry entry = getNext();
return new NameClassPair((String) entry.getKey(), entry.getValue().getClass().getName());
}
}
private class ListBindingEnumeration extends LocalNamingEnumeration
{
public Object next() throws NamingException
{
return nextElement();
}
public Object nextElement()
{
Map.Entry entry = getNext();
return new Binding((String) entry.getKey(), entry.getValue());
}
}
}