1 /*
   2  * Copyright (c) 1997, 2012, 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 com.sun.istack.internal.NotNull;
  29 
  30 /**
  31  * This class determines an instance of {@link Container} for the runtime.
  32  * It applies for both server and client runtimes(for e.g in Servlet could
  33  * be accessing a Web Service).
  34  *
  35  * A client that is invoking a web service may be running in a
  36  * container(for e.g servlet). T
  37  *
  38  * <p>
  39  * ContainerResolver uses a static field to keep the instance of the resolver object.
  40  * Typically appserver may set its custom container resolver using the static method
  41  * {@link #setInstance(ContainerResolver)}
  42  *
  43  * @author Jitendra Kotamraju
  44  */
  45 public abstract class ContainerResolver {
  46 
  47     private static final ThreadLocalContainerResolver DEFAULT = new ThreadLocalContainerResolver();
  48 
  49     private static volatile ContainerResolver theResolver = DEFAULT;
  50 
  51     /**
  52      * Sets the custom container resolver which can be used to get client's
  53      * {@link Container}.
  54      *
  55      * @param resolver container resolver
  56      */
  57     public static void setInstance(ContainerResolver resolver) {
  58         if(resolver==null)
  59             resolver = DEFAULT;
  60         theResolver = resolver;
  61     }
  62 
  63     /**
  64      * Returns the container resolver which can be used to get client's {@link Container}.
  65      *
  66      * @return container resolver instance
  67      */
  68     public static @NotNull ContainerResolver getInstance() {
  69         return theResolver;
  70     }
  71 
  72     /**
  73      * Returns the default container resolver which can be used to get {@link Container}.
  74      *
  75      * @return default container resolver
  76      */
  77     public static ThreadLocalContainerResolver getDefault() {
  78         return DEFAULT;
  79     }
  80 
  81     /**
  82      * Returns the {@link Container} context in which client is running.
  83      *
  84      * @return container instance for the client
  85      */
  86     public abstract @NotNull Container getContainer();
  87 
  88 }