1 /*

     2  * CDDL HEADER START

     3  *

     4  * The contents of this file are subject to the terms of the

     5  * Common Development and Distribution License (the "License").

     6  * You may not use this file except in compliance with the License.

     7  *

     8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

     9  * or http://www.opensolaris.org/os/licensing.

    10  * See the License for the specific language governing permissions

    11  * and limitations under the License.

    12  *

    13  * When distributing Covered Code, include this CDDL HEADER in each

    14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

    15  * If applicable, add the following below this CDDL HEADER, with the

    16  * fields enclosed by brackets "[]" replaced with your own identifying

    17  * information: Portions Copyright [yyyy] [name of copyright owner]

    18  *

    19  * CDDL HEADER END

    20  */

    21 

    22 /*

    23  * Copyright (c) 2009, 2012, Oracle and/or its affiliates. All rights reserved.

    24  */

    25 

    26 package com.oracle.solaris.vp.util.misc.finder;

    27 

    28 import java.security.*;

    29 

    30 public class ItemFinder implements FindingClass {

    31     //

    32     // Inner classes

    33     //

    34 

    35     // A number of classes in the JDK return the current thread's class stack

    36     // as a Class array, but none exposes this functionality publicly.  The

    37     // closest is SecurityManager, whose getClassContext method has protected

    38     // access.  Thus this hack.

    39     //

    40     // Note that java.lang.StackTraceElement is insufficient as it does not

    41     // return the actual Class objects in the stack, which are necessary to

    42     // retrieve each class's ClassLoader.

    43     //

    44     // An alternate approach would be to implement getClassContext() as a native

    45     // method.

    46     private static class MySecurityManager extends SecurityManager {

    47 	@Override

    48 	public Class[] getClassContext() {

    49 	    return super.getClassContext();

    50 	}

    51     }

    52 

    53     //

    54     // Static data

    55     //

    56 

    57     private static final MySecurityManager sManager = new MySecurityManager();

    58     private static final String className = ItemFinder.class.getName();

    59 

    60     //

    61     // Static methods

    62     //

    63 

    64     public static Class[] getClassContext() {

    65 	return sManager.getClassContext();

    66     }

    67 

    68     /**

    69      * Gets the first class under the last {@link FindingClass} in the class

    70      * stack.

    71      */

    72     public static Class getCallerClass() {

    73 	return AccessController.doPrivileged(

    74 	    new PrivilegedAction<Class>() {

    75 		@Override

    76 		public Class run() {

    77 		    return getCallerClassImp();

    78 		}

    79 	    });

    80     }

    81 

    82     //

    83     // Private static methods

    84     //

    85 

    86     private static Class getCallerClassImp() {

    87 	Class[] stack = getClassContext();

    88 	for (int i = stack.length - 2; i >= 0; i--) {

    89 	    if (FindingClass.class.isAssignableFrom(stack[i])) {

    90 		return stack[i + 1];

    91 	    }

    92 	}

    93 	return null;

    94     }

    95 }