1 /*

     2  * Copyright (c) 1999, 2008, 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 javax.management;

    27 

    28 // java import

    29 import java.io.Serializable;

    30 

    31 /**

    32  * Allows a query to be performed in the context of a specific MBean server.

    33  *

    34  * @since 1.5

    35  */

    36 public abstract class QueryEval implements Serializable {

    37 

    38     /* Serial version */

    39     private static final long serialVersionUID = 2675899265640874796L;

    40 

    41     private static ThreadLocal<MBeanServer> server =

    42         new InheritableThreadLocal<MBeanServer>();

    43 

    44     /**

    45      * <p>Sets the MBean server on which the query is to be performed.

    46      * The setting is valid for the thread performing the set.

    47      * It is copied to any threads created by that thread at the moment

    48      * of their creation.</p>

    49      *

    50      * <p>For historical reasons, this method is not static, but its

    51      * behavior does not depend on the instance on which it is

    52      * called.</p>

    53      *

    54      * @param s The MBean server on which the query is to be performed.

    55      *

    56      * @see #getMBeanServer

    57      */

    58     public void setMBeanServer(MBeanServer s) {

    59         server.set(s);

    60     }

    61 

    62     /**

    63      * <p>Return the MBean server that was most recently given to the

    64      * {@link #setMBeanServer setMBeanServer} method by this thread.

    65      * If this thread never called that method, the result is the

    66      * value its parent thread would have obtained from

    67      * <code>getMBeanServer</code> at the moment of the creation of

    68      * this thread, or null if there is no parent thread.</p>

    69      *

    70      * @return the MBean server.

    71      *

    72      * @see #setMBeanServer

    73      *

    74      */

    75     public static MBeanServer getMBeanServer() {

    76         return server.get();

    77     }

    78 }