1 /*
   2  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.xml.internal.ws.api.server;
  27 
  28 import java.util.concurrent.Executor;
  29 
  30 /**
  31  * ContainerResolver based on {@link ThreadLocal}.
  32  * <p>
  33  * The ThreadLocalContainerResolver is the default implementation available
  34  * from the ContainerResolver using {@link ContainerResolver#getDefault()}.  Code
  35  * sections that run with a Container must use the following pattern:
  36  * <pre>
  37  *   public void m() {
  38  *     Container old = ContainerResolver.getDefault().enterContainer(myContainer);
  39  *     try {
  40  *       // ... method body
  41  *     } finally {
  42  *       ContainerResolver.getDefault().exitContainer(old);
  43  *     }
  44  *   }
  45  * </pre>
  46  * @since 2.2.7
  47  */
  48 public class ThreadLocalContainerResolver extends ContainerResolver {
  49     private ThreadLocal<Container> containerThreadLocal = new ThreadLocal<Container>() {
  50         @Override
  51         protected Container initialValue() {
  52             return Container.NONE;
  53         }
  54     };
  55 
  56     public Container getContainer() {
  57         return containerThreadLocal.get();
  58     }
  59 
  60     /**
  61      * Enters container
  62      * @param container Container to set
  63      * @return Previous container; must be remembered and passed to exitContainer
  64      */
  65     public Container enterContainer(Container container) {
  66         Container old = containerThreadLocal.get();
  67         containerThreadLocal.set(container);
  68         return old;
  69     }
  70 
  71     /**
  72      * Exits container
  73      * @param old Container returned from enterContainer
  74      */
  75     public void exitContainer(Container old) {
  76         containerThreadLocal.set(old);
  77     }
  78 
  79     /**
  80      * Used by {@link com.sun.xml.internal.ws.api.pipe.Engine} to wrap asynchronous {@link com.sun.xml.internal.ws.api.pipe.Fiber} executions
  81      * @param container Container
  82      * @param ex Executor to wrap
  83      * @return an Executor that will set the container during executions of Runnables
  84      */
  85     public Executor wrapExecutor(final Container container, final Executor ex) {
  86         if (ex == null)
  87             return null;
  88 
  89         return new Executor() {
  90             @Override
  91             public void execute(final Runnable command) {
  92                 ex.execute(new Runnable() {
  93                     @Override
  94                     public void run() {
  95                         Container old = enterContainer(container);
  96                         try {
  97                             command.run();
  98                         } finally {
  99                             exitContainer(old);
 100                         }
 101                     }
 102                 });
 103             }
 104         };
 105     }
 106 }