View Javadoc

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  
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 {
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       */
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  
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  
81      static final public void report(String msg) {
82          System.err.println("SLF4J: " + msg);
83      }
84  }