org.eclipse.jetty.jndi.ContextFactory Maven / Gradle / Ivy
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//
// ========================================================================
// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
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//
package org.eclipse.jetty.jndi;
import java.io.IOException;
import java.util.Collections;
import java.util.Hashtable;
import java.util.Map;
import java.util.WeakHashMap;
import javax.naming.Context;
import javax.naming.Name;
import javax.naming.NameParser;
import javax.naming.Reference;
import javax.naming.StringRefAddr;
import javax.naming.spi.ObjectFactory;
import org.eclipse.jetty.server.handler.ContextHandler;
import org.eclipse.jetty.util.component.Dumpable;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
/**
* ContextFactory
*
* This is an object factory that produces a jndi naming
* context based on a classloader.
*
* It is used for the java:comp context.
*
* This object factory is bound at java:comp. When a
* lookup arrives for java:comp, this object factory
* is invoked and will return a context specific to
* the caller's environment (so producing the java:comp/env
* specific to a webapp).
*
* The context selected is based on classloaders. First
* we try looking at the thread context classloader if it is set, and walk its
* hierarchy, creating a context if none is found. If the thread context classloader
* is not set, then we use the classloader associated with the current Context.
*
* If there is no current context, or no classloader, we return null.
*/
public class ContextFactory implements ObjectFactory
{
private static final Logger LOG = Log.getLogger(ContextFactory.class);
/**
* Map of classloaders to contexts.
*/
private static final Map __contextMap = Collections.synchronizedMap(new WeakHashMap<>());
/**
* Threadlocal for injecting a context to use
* instead of looking up the map.
*/
private static final ThreadLocal __threadContext = new ThreadLocal();
/**
* Threadlocal for setting a classloader which must be used
* when finding the comp context.
*/
private static final ThreadLocal __threadClassLoader = new ThreadLocal();
/**
* Find or create a context which pertains to a classloader.
*
* If the thread context classloader is set, we try to find an already-created naming context
* for it. If one does not exist, we walk its classloader hierarchy until one is found, or we
* run out of parent classloaders. In the latter case, we will create a new naming context associated
* with the original thread context classloader.
*
* If the thread context classloader is not set, we obtain the classloader from the current
* jetty Context, and look for an already-created naming context.
*
* If there is no current jetty Context, or it has no associated classloader, we
* return null.
*
* @see javax.naming.spi.ObjectFactory#getObjectInstance(java.lang.Object, javax.naming.Name, javax.naming.Context, java.util.Hashtable)
*/
@Override
public Object getObjectInstance(Object obj,
Name name,
Context nameCtx,
Hashtable env)
throws Exception
{
//First, see if we have had a context injected into us to use.
Context ctx = __threadContext.get();
if (ctx != null)
{
if (LOG.isDebugEnabled())
LOG.debug("Using the Context that is bound on the thread");
return ctx;
}
//See if there is a classloader to use for finding the comp context
//Don't use its parent hierarchy if set.
ClassLoader loader = __threadClassLoader.get();
if (loader != null)
{
if (LOG.isDebugEnabled())
LOG.debug("Using threadlocal classloader");
synchronized (__contextMap)
{
ctx = getContextForClassLoader(loader);
if (ctx == null)
{
ctx = newNamingContext(obj, loader, env, name, nameCtx);
__contextMap.put(loader, ctx);
if (LOG.isDebugEnabled())
LOG.debug("Made context {} for classloader {}", name.get(0), loader);
}
return ctx;
}
}
//If the thread context classloader is set, then try its hierarchy to find a matching context
ClassLoader tccl = Thread.currentThread().getContextClassLoader();
loader = tccl;
if (loader != null)
{
if (LOG.isDebugEnabled())
LOG.debug("Trying thread context classloader");
synchronized (__contextMap)
{
while (ctx == null && loader != null)
{
ctx = getContextForClassLoader(loader);
if (ctx == null && loader != null)
loader = loader.getParent();
}
if (ctx == null)
{
ctx = newNamingContext(obj, tccl, env, name, nameCtx);
__contextMap.put(tccl, ctx);
if (LOG.isDebugEnabled())
LOG.debug("Made context {} for classloader {}", name.get(0), tccl);
}
return ctx;
}
}
//If trying thread context classloader hierarchy failed, try the
//classloader associated with the current context
if (ContextHandler.getCurrentContext() != null)
{
if (LOG.isDebugEnabled() && loader != null)
LOG.debug("Trying classloader of current org.eclipse.jetty.server.handler.ContextHandler");
synchronized (__contextMap)
{
loader = ContextHandler.getCurrentContext().getContextHandler().getClassLoader();
ctx = __contextMap.get(loader);
if (ctx == null && loader != null)
{
ctx = newNamingContext(obj, loader, env, name, nameCtx);
__contextMap.put(loader, ctx);
if (LOG.isDebugEnabled())
LOG.debug("Made context {} for classloader {} ", name.get(0), loader);
}
return ctx;
}
}
return null;
}
/**
* Create a new NamingContext.
*
* @param obj the object to create
* @param loader the classloader for the naming context
* @param env the jndi env for the entry
* @param name the name of the entry
* @param parentCtx the parent context of the entry
* @return the newly created naming context
* @throws Exception if unable to create a new naming context
*/
public NamingContext newNamingContext(Object obj, ClassLoader loader, Hashtable env, Name name, Context parentCtx)
throws Exception
{
Reference ref = (Reference)obj;
StringRefAddr parserAddr = (StringRefAddr)ref.get("parser");
String parserClassName = (parserAddr == null ? null : (String)parserAddr.getContent());
NameParser parser =
(NameParser)(parserClassName == null ? null : loader.loadClass(parserClassName).getDeclaredConstructor().newInstance());
return new NamingContext(env,
name.get(0),
(NamingContext)parentCtx,
parser);
}
/**
* Find the naming Context for the given classloader
*
* @param loader the classloader for the context
* @return the context for the classloader
*/
public Context getContextForClassLoader(ClassLoader loader)
{
if (loader == null)
return null;
return __contextMap.get(loader);
}
/**
* Associate the given Context with the current thread.
* disassociate method should be called to reset the context.
*
* @param ctx the context to associate to the current thread.
* @return the previous context associated on the thread (can be null)
*/
public static Context associateContext(final Context ctx)
{
Context previous = __threadContext.get();
__threadContext.set(ctx);
return previous;
}
public static void disassociateContext(final Context ctx)
{
__threadContext.set(null);
}
public static ClassLoader associateClassLoader(final ClassLoader loader)
{
ClassLoader prev = __threadClassLoader.get();
__threadClassLoader.set(loader);
return prev;
}
public static void disassociateClassLoader()
{
__threadClassLoader.set(null);
}
public static void dump(Appendable out, String indent) throws IOException
{
synchronized (__contextMap)
{
Dumpable.dumpObjects(out, indent, String.format("o.e.j.jndi.ContextFactory@%x", __contextMap.hashCode()), __contextMap);
}
}
}