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Jetty example source code file (ContextFactory.java)
The Jetty ContextFactory.java source code// ======================================================================== // $Id: ContextFactory.java 1327 2006-11-27 18:40:14Z janb $ // Copyright 1999-2006 Mort Bay Consulting Pty. Ltd. // ------------------------------------------------------------------------ // Licensed 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.mortbay.naming; import java.util.Hashtable; 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.mortbay.jetty.handler.ContextHandler; import org.mortbay.log.Log; /** * ContextFactory.java * * 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 in at the classloader that is associated * with the current webapp context (if there is one). If * not, we use the thread context classloader. * * Created: Fri Jun 27 09:26:40 2003 * * @author <a href="mailto:janb@mortbay.com">Jan Bartel * */ public class ContextFactory implements ObjectFactory { /** * Map of classloaders to contexts. */ private static WeakHashMap _contextMap; /** * Threadlocal for injecting a context to use * instead of looking up the map. */ private static ThreadLocal _threadContext; static { _contextMap = new WeakHashMap(); _threadContext = new ThreadLocal(); } /** * Find or create a context which pertains to a classloader. * * We use either the classloader for the current ContextHandler if * we are handling a request, OR we use the thread context classloader * if we are not processing a request. * @see javax.naming.spi.ObjectFactory#getObjectInstance(java.lang.Object, javax.naming.Name, javax.naming.Context, java.util.Hashtable) */ 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 = (Context)_threadContext.get(); if (ctx != null) { if(Log.isDebugEnabled()) Log.debug("Using the Context that is bound on the thread"); return ctx; } // Next, see if we are in a webapp context, if we are, use // the classloader of the webapp to find the right jndi comp context ClassLoader loader = null; if (ContextHandler.getCurrentContext() != null) { loader = ContextHandler.getCurrentContext().getContextHandler().getClassLoader(); } if (loader != null) { if (Log.isDebugEnabled()) Log.debug("Using classloader of current org.mortbay.jetty.handler.ContextHandler"); } else { //Not already in a webapp context, in that case, we try the //curren't thread's classloader instead loader = Thread.currentThread().getContextClassLoader(); if (Log.isDebugEnabled()) Log.debug("Using thread context classloader"); } //Get the context matching the classloader ctx = (Context)_contextMap.get(loader); //The map does not contain an entry for this classloader if (ctx == null) { //Check if a parent classloader has created the context ctx = getParentClassLoaderContext(loader); //Didn't find a context to match any of the ancestors //of the classloader, so make a context if (ctx == null) { 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).newInstance()); ctx = new NamingContext (env, name.get(0), nameCtx, parser); if(Log.isDebugEnabled())Log.debug("No entry for classloader: "+loader); _contextMap.put (loader, ctx); } } return ctx; } /** * Keep trying ancestors of the given classloader to find one to which * the context is bound. * @param loader * @return */ public Context getParentClassLoaderContext (ClassLoader loader) { Context ctx = null; ClassLoader cl = loader; for (cl = cl.getParent(); (cl != null) && (ctx == null); cl = cl.getParent()) { ctx = (Context)_contextMap.get(cl); } return ctx; } /** * Associate the given Context with the current thread. * resetComponentContext 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 setComponentContext(final Context ctx) { Context previous = (Context)_threadContext.get(); _threadContext.set(ctx); return previous; } /** * Set back the context with the given value. * Don't return the previous context, use setComponentContext() method for this. * @param ctx the context to associate to the current thread. */ public static void resetComponentContext(final Context ctx) { _threadContext.set(ctx); } } Other Jetty examples (source code examples)Here is a short list of links related to this Jetty ContextFactory.java source code file: |
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