1 /* 2 * Copyright 2001-2004 The Apache Software Foundation. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package org.apache.log4j.helpers; 18 19 /** 20 This class used to output log statements from within the log4j package. 21 22 <p>Log4j components cannot make log4j logging calls. However, it is 23 sometimes useful for the user to learn about what log4j is 24 doing. You can enable log4j internal logging by defining the 25 <b>log4j.configDebug</b> variable. 26 27 <p>All log4j internal debug calls go to <code>System.out</code> 28 where as internal error messages are sent to 29 <code>System.err</code>. All internal messages are prepended with 30 the string "log4j: ". 31 32 @since 0.8.2 33 @author Ceki Gülcü 34 */ 35 public class LogLog { 36 37 /** 38 Defining this value makes log4j print log4j-internal debug 39 statements to <code>System.out</code>. 40 41 <p> The value of this string is <b>log4j.debug</b>. 42 43 <p>Note that the search for all option names is case sensitive. */ 44 public static final String DEBUG_KEY = "log4j.debug"; 45 46 /** 47 Defining this value makes log4j components print log4j-internal 48 debug statements to <code>System.out</code>. 49 50 <p> The value of this string is <b>log4j.configDebug</b>. 51 52 <p>Note that the search for all option names is case sensitive. 53 54 @deprecated Use {@link #DEBUG_KEY} instead. 55 */ 56 public static final String CONFIG_DEBUG_KEY = "log4j.configDebug"; 57 58 protected static boolean debugEnabled = false; 59 60 /** 61 In quietMode not even errors generate any output. 62 */ 63 private static boolean quietMode = false; 64 65 private static final String PREFIX = "log4j: "; 66 private static final String ERR_PREFIX = "log4j:ERROR "; 67 private static final String WARN_PREFIX = "log4j:WARN "; 68 69 static { 70 } 71 72 /** 73 Allows to enable/disable log4j internal logging. 74 */ 75 static public void setInternalDebugging(boolean enabled) { 76 debugEnabled = enabled; 77 } 78 79 /** 80 This method is used to output log4j internal debug 81 statements. Output goes to <code>System.out</code>. 82 */ 83 public static void debug(String msg) { 84 if (debugEnabled && !quietMode) { 85 System.out.println(PREFIX + msg); 86 } 87 } 88 89 /** 90 This method is used to output log4j internal debug 91 statements. Output goes to <code>System.out</code>. 92 */ 93 public static void debug(String msg, Throwable t) { 94 if (debugEnabled && !quietMode) { 95 System.out.println(PREFIX + msg); 96 if (t != null) 97 t.printStackTrace(System.out); 98 } 99 } 100 101 /** 102 This method is used to output log4j internal error 103 statements. There is no way to disable error statements. 104 Output goes to <code>System.err</code>. 105 */ 106 public static void error(String msg) { 107 if (quietMode) 108 return; 109 System.err.println(ERR_PREFIX + msg); 110 } 111 112 /** 113 This method is used to output log4j internal error 114 statements. There is no way to disable error statements. 115 Output goes to <code>System.err</code>. 116 */ 117 public static void error(String msg, Throwable t) { 118 if (quietMode) 119 return; 120 121 System.err.println(ERR_PREFIX + msg); 122 if (t != null) { 123 t.printStackTrace(); 124 } 125 } 126 127 /** 128 In quite mode no LogLog generates strictly no output, not even 129 for errors. 130 131 @param quietMode A true for not 132 */ 133 public static void setQuietMode(boolean quietMode) { 134 LogLog.quietMode = quietMode; 135 } 136 137 /** 138 This method is used to output log4j internal warning 139 statements. There is no way to disable warning statements. 140 Output goes to <code>System.err</code>. */ 141 public static void warn(String msg) { 142 if (quietMode) 143 return; 144 145 System.err.println(WARN_PREFIX + msg); 146 } 147 148 /** 149 This method is used to output log4j internal warnings. There is 150 no way to disable warning statements. Output goes to 151 <code>System.err</code>. */ 152 public static void warn(String msg, Throwable t) { 153 if (quietMode) 154 return; 155 156 System.err.println(WARN_PREFIX + msg); 157 if (t != null) { 158 t.printStackTrace(); 159 } 160 } 161 }