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 safeGetSystemProperty(String key)38 public static String safeGetSystemProperty(String key) { 39 if (key == null) 40 throw new IllegalArgumentException("null input"); 41 42 String result = null; 43 try { 44 result = System.getProperty(key); 45 } catch (java.lang.SecurityException sm) { 46 ; // ignore 47 } 48 return result; 49 } 50 safeGetBooleanSystemProperty(String key)51 public static boolean safeGetBooleanSystemProperty(String key) { 52 String value = safeGetSystemProperty(key); 53 if (value == null) 54 return false; 55 else 56 return value.equalsIgnoreCase("true"); 57 } 58 59 /** 60 * In order to call {@link SecurityManager#getClassContext()}, which is a 61 * protected method, we add this wrapper which allows the method to be visible 62 * inside this package. 63 */ 64 private static final class ClassContextSecurityManager extends SecurityManager { getClassContext()65 protected Class<?>[] getClassContext() { 66 return super.getClassContext(); 67 } 68 } 69 70 private static ClassContextSecurityManager SECURITY_MANAGER; 71 private static boolean SECURITY_MANAGER_CREATION_ALREADY_ATTEMPTED = false; 72 getSecurityManager()73 private static ClassContextSecurityManager getSecurityManager() { 74 if (SECURITY_MANAGER != null) 75 return SECURITY_MANAGER; 76 else if (SECURITY_MANAGER_CREATION_ALREADY_ATTEMPTED) 77 return null; 78 else { 79 SECURITY_MANAGER = safeCreateSecurityManager(); 80 SECURITY_MANAGER_CREATION_ALREADY_ATTEMPTED = true; 81 return SECURITY_MANAGER; 82 } 83 } 84 safeCreateSecurityManager()85 private static ClassContextSecurityManager safeCreateSecurityManager() { 86 try { 87 return new ClassContextSecurityManager(); 88 } catch (java.lang.SecurityException sm) { 89 return null; 90 } 91 } 92 93 /** 94 * Returns the name of the class which called the invoking method. 95 * 96 * @return the name of the class which called the invoking method. 97 */ getCallingClass()98 public static Class<?> getCallingClass() { 99 ClassContextSecurityManager securityManager = getSecurityManager(); 100 if (securityManager == null) 101 return null; 102 Class<?>[] trace = securityManager.getClassContext(); 103 String thisClassName = Util.class.getName(); 104 105 // Advance until Util is found 106 int i; 107 for (i = 0; i < trace.length; i++) { 108 if (thisClassName.equals(trace[i].getName())) 109 break; 110 } 111 112 // trace[i] = Util; trace[i+1] = caller; trace[i+2] = caller's caller 113 if (i >= trace.length || i + 2 >= trace.length) { 114 throw new IllegalStateException("Failed to find org.slf4j.helpers.Util or its caller in the stack; " + "this should not happen"); 115 } 116 117 return trace[i + 2]; 118 } 119 120 /** 121 * See {@link Reporter#error(String, Throwable)} class for alternative. 122 * 123 * @deprecated replaced by the {@link Reporter#error(String, Throwable)} method. 124 * @param msg message to print 125 * @param t throwable to print 126 */ report(String msg, Throwable t)127 static final public void report(String msg, Throwable t) { 128 System.err.println(msg); 129 System.err.println("Reported exception:"); 130 t.printStackTrace(); 131 } 132 133 /** 134 * See {@link Reporter} class for alternatives. 135 * 136 * @deprecated replaced by one of {@link Reporter#info(String)}, 137 * {@link Reporter#warn(String)} or {@link Reporter#error(String)} methods. 138 * @param msg message to print 139 */ report(String msg)140 static final public void report(String msg) { 141 System.err.println("SLF4J: " + msg); 142 } 143 144 } 145