1 /**
2  * Copyright (c) 2004-2011 QOS.ch
3  * All rights reserved.
4  *
5  * Permission is hereby granted, free  of charge, to any person obtaining
6  * a  copy  of this  software  and  associated  documentation files  (the
7  * "Software"), to  deal in  the Software without  restriction, including
8  * without limitation  the rights to  use, copy, modify,  merge, publish,
9  * distribute,  sublicense, and/or sell  copies of  the Software,  and to
10  * permit persons to whom the Software  is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The  above  copyright  notice  and  this permission  notice  shall  be
14  * included in all copies or substantial portions of the Software.
15  *
16  * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
17  * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
18  * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
19  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21  * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23  *
24  */
25 package org.slf4j.helpers;
26 
27 /**
28  * An internal utility class.
29  *
30  * @author Alexander Dorokhine
31  * @author Ceki Gülcü
32  */
33 public final class Util {
34 
Util()35     private Util() {
36     }
37 
38     /**
39      * In order to call {@link SecurityManager#getClassContext()}, which is a
40      * protected method, we add this wrapper which allows the method to be visible
41      * inside this package.
42      */
43     private static final class ClassContextSecurityManager extends SecurityManager {
getClassContext()44         protected Class<?>[] getClassContext() {
45             return super.getClassContext();
46         }
47     }
48 
49     private static final ClassContextSecurityManager SECURITY_MANAGER = new ClassContextSecurityManager();
50 
51     /**
52      * Returns the name of the class which called the invoking method.
53      *
54      * @return the name of the class which called the invoking method.
55      */
getCallingClass()56     public static Class<?> getCallingClass() {
57         Class<?>[] trace = SECURITY_MANAGER.getClassContext();
58         String thisClassName = Util.class.getName();
59 
60         // Advance until Util is found
61         int i;
62         for (i = 0; i < trace.length; i++) {
63             if (thisClassName.equals(trace[i].getName()))
64                 break;
65         }
66 
67         // trace[i] = Util; trace[i+1] = caller; trace[i+2] = caller's caller
68         if (i >= trace.length || i + 2 >= trace.length) {
69             throw new IllegalStateException("Failed to find org.slf4j.helpers.Util or its caller in the stack; " + "this should not happen");
70         }
71 
72         return trace[i + 2];
73     }
74 
report(String msg, Throwable t)75     static final public void report(String msg, Throwable t) {
76         System.err.println(msg);
77         System.err.println("Reported exception:");
78         t.printStackTrace();
79     }
80 
report(String msg)81     static final public void report(String msg) {
82         System.err.println("SLF4J: " + msg);
83     }
84 }
85