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| <FONT color="green">001</FONT> /*<a name="line.1"></a> |
| <FONT color="green">002</FONT> * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a> |
| <FONT color="green">003</FONT> * contributor license agreements. See the NOTICE file distributed with<a name="line.3"></a> |
| <FONT color="green">004</FONT> * this work for additional information regarding copyright ownership.<a name="line.4"></a> |
| <FONT color="green">005</FONT> * The ASF licenses this file to You under the Apache license, Version 2.0<a name="line.5"></a> |
| <FONT color="green">006</FONT> * (the "License"); you may not use this file except in compliance with<a name="line.6"></a> |
| <FONT color="green">007</FONT> * the License. You may obtain a copy of the License at<a name="line.7"></a> |
| <FONT color="green">008</FONT> *<a name="line.8"></a> |
| <FONT color="green">009</FONT> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a> |
| <FONT color="green">010</FONT> *<a name="line.10"></a> |
| <FONT color="green">011</FONT> * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a> |
| <FONT color="green">012</FONT> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a> |
| <FONT color="green">013</FONT> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a> |
| <FONT color="green">014</FONT> * See the license for the specific language governing permissions and<a name="line.14"></a> |
| <FONT color="green">015</FONT> * limitations under the license.<a name="line.15"></a> |
| <FONT color="green">016</FONT> */<a name="line.16"></a> |
| <FONT color="green">017</FONT> package org.apache.log4j;<a name="line.17"></a> |
| <FONT color="green">018</FONT> <a name="line.18"></a> |
| <FONT color="green">019</FONT> import java.util.Stack;<a name="line.19"></a> |
| <FONT color="green">020</FONT> <a name="line.20"></a> |
| <FONT color="green">021</FONT> /**<a name="line.21"></a> |
| <FONT color="green">022</FONT> *<a name="line.22"></a> |
| <FONT color="green">023</FONT> */<a name="line.23"></a> |
| <FONT color="green">024</FONT> public final class NDC {<a name="line.24"></a> |
| <FONT color="green">025</FONT> <a name="line.25"></a> |
| <FONT color="green">026</FONT> private NDC() {<a name="line.26"></a> |
| <FONT color="green">027</FONT> }<a name="line.27"></a> |
| <FONT color="green">028</FONT> <a name="line.28"></a> |
| <FONT color="green">029</FONT> /**<a name="line.29"></a> |
| <FONT color="green">030</FONT> * Clear any nested diagnostic information if any. This method is<a name="line.30"></a> |
| <FONT color="green">031</FONT> * useful in cases where the same thread can be potentially used<a name="line.31"></a> |
| <FONT color="green">032</FONT> * over and over in different unrelated contexts.<a name="line.32"></a> |
| <FONT color="green">033</FONT> * <p/><a name="line.33"></a> |
| <FONT color="green">034</FONT> * <p>This method is equivalent to calling the {@link #setMaxDepth}<a name="line.34"></a> |
| <FONT color="green">035</FONT> * method with a zero <code>maxDepth</code> argument.<a name="line.35"></a> |
| <FONT color="green">036</FONT> */<a name="line.36"></a> |
| <FONT color="green">037</FONT> public static void clear() {<a name="line.37"></a> |
| <FONT color="green">038</FONT> org.apache.logging.log4j.ThreadContext.clearStack();<a name="line.38"></a> |
| <FONT color="green">039</FONT> }<a name="line.39"></a> |
| <FONT color="green">040</FONT> <a name="line.40"></a> |
| <FONT color="green">041</FONT> <a name="line.41"></a> |
| <FONT color="green">042</FONT> /**<a name="line.42"></a> |
| <FONT color="green">043</FONT> * Clone the diagnostic context for the current thread.<a name="line.43"></a> |
| <FONT color="green">044</FONT> * <p/><a name="line.44"></a> |
| <FONT color="green">045</FONT> * <p>Internally a diagnostic context is represented as a stack. A<a name="line.45"></a> |
| <FONT color="green">046</FONT> * given thread can supply the stack (i.e. diagnostic context) to a<a name="line.46"></a> |
| <FONT color="green">047</FONT> * child thread so that the child can inherit the parent thread's<a name="line.47"></a> |
| <FONT color="green">048</FONT> * diagnostic context.<a name="line.48"></a> |
| <FONT color="green">049</FONT> * <p/><a name="line.49"></a> |
| <FONT color="green">050</FONT> * <p>The child thread uses the {@link #inherit inherit} method to<a name="line.50"></a> |
| <FONT color="green">051</FONT> * inherit the parent's diagnostic context.<a name="line.51"></a> |
| <FONT color="green">052</FONT> *<a name="line.52"></a> |
| <FONT color="green">053</FONT> * @return Stack A clone of the current thread's diagnostic context.<a name="line.53"></a> |
| <FONT color="green">054</FONT> */<a name="line.54"></a> |
| <FONT color="green">055</FONT> public static Stack cloneStack() {<a name="line.55"></a> |
| <FONT color="green">056</FONT> return org.apache.logging.log4j.ThreadContext.cloneStack();<a name="line.56"></a> |
| <FONT color="green">057</FONT> }<a name="line.57"></a> |
| <FONT color="green">058</FONT> <a name="line.58"></a> |
| <FONT color="green">059</FONT> <a name="line.59"></a> |
| <FONT color="green">060</FONT> /**<a name="line.60"></a> |
| <FONT color="green">061</FONT> * Inherit the diagnostic context of another thread.<a name="line.61"></a> |
| <FONT color="green">062</FONT> * <p/><a name="line.62"></a> |
| <FONT color="green">063</FONT> * <p>The parent thread can obtain a reference to its diagnostic<a name="line.63"></a> |
| <FONT color="green">064</FONT> * context using the {@link #cloneStack} method. It should<a name="line.64"></a> |
| <FONT color="green">065</FONT> * communicate this information to its child so that it may inherit<a name="line.65"></a> |
| <FONT color="green">066</FONT> * the parent's diagnostic context.<a name="line.66"></a> |
| <FONT color="green">067</FONT> * <p/><a name="line.67"></a> |
| <FONT color="green">068</FONT> * <p>The parent's diagnostic context is cloned before being<a name="line.68"></a> |
| <FONT color="green">069</FONT> * inherited. In other words, once inherited, the two diagnostic<a name="line.69"></a> |
| <FONT color="green">070</FONT> * contexts can be managed independently.<a name="line.70"></a> |
| <FONT color="green">071</FONT> * <p/><a name="line.71"></a> |
| <FONT color="green">072</FONT> * <p>In java, a child thread cannot obtain a reference to its<a name="line.72"></a> |
| <FONT color="green">073</FONT> * parent, unless it is directly handed the reference. Consequently,<a name="line.73"></a> |
| <FONT color="green">074</FONT> * there is no client-transparent way of inheriting diagnostic<a name="line.74"></a> |
| <FONT color="green">075</FONT> * contexts. Do you know any solution to this problem?<a name="line.75"></a> |
| <FONT color="green">076</FONT> *<a name="line.76"></a> |
| <FONT color="green">077</FONT> * @param stack The diagnostic context of the parent thread.<a name="line.77"></a> |
| <FONT color="green">078</FONT> */<a name="line.78"></a> |
| <FONT color="green">079</FONT> public static void inherit(Stack stack) {<a name="line.79"></a> |
| <FONT color="green">080</FONT> org.apache.logging.log4j.ThreadContext.setStack(stack);<a name="line.80"></a> |
| <FONT color="green">081</FONT> }<a name="line.81"></a> |
| <FONT color="green">082</FONT> <a name="line.82"></a> |
| <FONT color="green">083</FONT> <a name="line.83"></a> |
| <FONT color="green">084</FONT> /**<a name="line.84"></a> |
| <FONT color="green">085</FONT> * <font color="#FF4040"><b>Never use this method directly.</b><a name="line.85"></a> |
| <FONT color="green">086</FONT> * @return The string value of the specified key.<a name="line.86"></a> |
| <FONT color="green">087</FONT> */<a name="line.87"></a> |
| <FONT color="green">088</FONT> public static String get() {<a name="line.88"></a> |
| <FONT color="green">089</FONT> return org.apache.logging.log4j.ThreadContext.peek();<a name="line.89"></a> |
| <FONT color="green">090</FONT> }<a name="line.90"></a> |
| <FONT color="green">091</FONT> <a name="line.91"></a> |
| <FONT color="green">092</FONT> /**<a name="line.92"></a> |
| <FONT color="green">093</FONT> * Get the current nesting depth of this diagnostic context.<a name="line.93"></a> |
| <FONT color="green">094</FONT> * @return int The number of elements in the call stack.<a name="line.94"></a> |
| <FONT color="green">095</FONT> * @see #setMaxDepth<a name="line.95"></a> |
| <FONT color="green">096</FONT> */<a name="line.96"></a> |
| <FONT color="green">097</FONT> public static int getDepth() {<a name="line.97"></a> |
| <FONT color="green">098</FONT> return org.apache.logging.log4j.ThreadContext.getDepth();<a name="line.98"></a> |
| <FONT color="green">099</FONT> }<a name="line.99"></a> |
| <FONT color="green">100</FONT> <a name="line.100"></a> |
| <FONT color="green">101</FONT> /**<a name="line.101"></a> |
| <FONT color="green">102</FONT> * Clients should call this method before leaving a diagnostic<a name="line.102"></a> |
| <FONT color="green">103</FONT> * context.<a name="line.103"></a> |
| <FONT color="green">104</FONT> * <p/><a name="line.104"></a> |
| <FONT color="green">105</FONT> * <p>The returned value is the value that was pushed last. If no<a name="line.105"></a> |
| <FONT color="green">106</FONT> * context is available, then the empty string "" is returned.<a name="line.106"></a> |
| <FONT color="green">107</FONT> *<a name="line.107"></a> |
| <FONT color="green">108</FONT> * @return String The innermost diagnostic context.<a name="line.108"></a> |
| <FONT color="green">109</FONT> */<a name="line.109"></a> |
| <FONT color="green">110</FONT> public static String pop() {<a name="line.110"></a> |
| <FONT color="green">111</FONT> return org.apache.logging.log4j.ThreadContext.pop();<a name="line.111"></a> |
| <FONT color="green">112</FONT> }<a name="line.112"></a> |
| <FONT color="green">113</FONT> <a name="line.113"></a> |
| <FONT color="green">114</FONT> /**<a name="line.114"></a> |
| <FONT color="green">115</FONT> * Looks at the last diagnostic context at the top of this NDC<a name="line.115"></a> |
| <FONT color="green">116</FONT> * without removing it.<a name="line.116"></a> |
| <FONT color="green">117</FONT> * <p/><a name="line.117"></a> |
| <FONT color="green">118</FONT> * <p>The returned value is the value that was pushed last. If no<a name="line.118"></a> |
| <FONT color="green">119</FONT> * context is available, then the empty string "" is returned.<a name="line.119"></a> |
| <FONT color="green">120</FONT> *<a name="line.120"></a> |
| <FONT color="green">121</FONT> * @return String The innermost diagnostic context.<a name="line.121"></a> |
| <FONT color="green">122</FONT> */<a name="line.122"></a> |
| <FONT color="green">123</FONT> public static String peek() {<a name="line.123"></a> |
| <FONT color="green">124</FONT> return org.apache.logging.log4j.ThreadContext.peek();<a name="line.124"></a> |
| <FONT color="green">125</FONT> }<a name="line.125"></a> |
| <FONT color="green">126</FONT> <a name="line.126"></a> |
| <FONT color="green">127</FONT> /**<a name="line.127"></a> |
| <FONT color="green">128</FONT> * Push new diagnostic context information for the current thread.<a name="line.128"></a> |
| <FONT color="green">129</FONT> * <p/><a name="line.129"></a> |
| <FONT color="green">130</FONT> * <p>The contents of the <code>message</code> parameter is<a name="line.130"></a> |
| <FONT color="green">131</FONT> * determined solely by the client.<a name="line.131"></a> |
| <FONT color="green">132</FONT> *<a name="line.132"></a> |
| <FONT color="green">133</FONT> * @param message The new diagnostic context information.<a name="line.133"></a> |
| <FONT color="green">134</FONT> */<a name="line.134"></a> |
| <FONT color="green">135</FONT> public static void push(String message) {<a name="line.135"></a> |
| <FONT color="green">136</FONT> org.apache.logging.log4j.ThreadContext.push(message);<a name="line.136"></a> |
| <FONT color="green">137</FONT> }<a name="line.137"></a> |
| <FONT color="green">138</FONT> <a name="line.138"></a> |
| <FONT color="green">139</FONT> /**<a name="line.139"></a> |
| <FONT color="green">140</FONT> * Remove the diagnostic context for this thread.<a name="line.140"></a> |
| <FONT color="green">141</FONT> * <p/><a name="line.141"></a> |
| <FONT color="green">142</FONT> * <p>Each thread that created a diagnostic context by calling<a name="line.142"></a> |
| <FONT color="green">143</FONT> * {@link #push} should call this method before exiting. Otherwise,<a name="line.143"></a> |
| <FONT color="green">144</FONT> * the memory used by the <b>thread</b> cannot be reclaimed by the<a name="line.144"></a> |
| <FONT color="green">145</FONT> * VM.<a name="line.145"></a> |
| <FONT color="green">146</FONT> * <p/><a name="line.146"></a> |
| <FONT color="green">147</FONT> * <p>As this is such an important problem in heavy duty systems and<a name="line.147"></a> |
| <FONT color="green">148</FONT> * because it is difficult to always guarantee that the remove<a name="line.148"></a> |
| <FONT color="green">149</FONT> * method is called before exiting a thread, this method has been<a name="line.149"></a> |
| <FONT color="green">150</FONT> * augmented to lazily remove references to dead threads. In<a name="line.150"></a> |
| <FONT color="green">151</FONT> * practice, this means that you can be a little sloppy and<a name="line.151"></a> |
| <FONT color="green">152</FONT> * occasionally forget to call {@link #remove} before exiting a<a name="line.152"></a> |
| <FONT color="green">153</FONT> * thread. However, you must call <code>remove</code> sometime. If<a name="line.153"></a> |
| <FONT color="green">154</FONT> * you never call it, then your application is sure to run out of<a name="line.154"></a> |
| <FONT color="green">155</FONT> * memory.<a name="line.155"></a> |
| <FONT color="green">156</FONT> */<a name="line.156"></a> |
| <FONT color="green">157</FONT> public static void remove() {<a name="line.157"></a> |
| <FONT color="green">158</FONT> org.apache.logging.log4j.ThreadContext.removeStack();<a name="line.158"></a> |
| <FONT color="green">159</FONT> }<a name="line.159"></a> |
| <FONT color="green">160</FONT> <a name="line.160"></a> |
| <FONT color="green">161</FONT> /**<a name="line.161"></a> |
| <FONT color="green">162</FONT> * Set maximum depth of this diagnostic context. If the current<a name="line.162"></a> |
| <FONT color="green">163</FONT> * depth is smaller or equal to <code>maxDepth</code>, then no<a name="line.163"></a> |
| <FONT color="green">164</FONT> * action is taken.<a name="line.164"></a> |
| <FONT color="green">165</FONT> * <p/><a name="line.165"></a> |
| <FONT color="green">166</FONT> * <p>This method is a convenient alternative to multiple {@link<a name="line.166"></a> |
| <FONT color="green">167</FONT> * #pop} calls. Moreover, it is often the case that at the end of<a name="line.167"></a> |
| <FONT color="green">168</FONT> * complex call sequences, the depth of the NDC is<a name="line.168"></a> |
| <FONT color="green">169</FONT> * unpredictable. The <code>setMaxDepth</code> method circumvents<a name="line.169"></a> |
| <FONT color="green">170</FONT> * this problem.<a name="line.170"></a> |
| <FONT color="green">171</FONT> * <p/><a name="line.171"></a> |
| <FONT color="green">172</FONT> * <p>For example, the combination<a name="line.172"></a> |
| <FONT color="green">173</FONT> * <pre><a name="line.173"></a> |
| <FONT color="green">174</FONT> * void foo() {<a name="line.174"></a> |
| <FONT color="green">175</FONT> * &nbsp; int depth = NDC.getDepth();<a name="line.175"></a> |
| <FONT color="green">176</FONT> * <p/><a name="line.176"></a> |
| <FONT color="green">177</FONT> * &nbsp; ... complex sequence of calls<a name="line.177"></a> |
| <FONT color="green">178</FONT> * <p/><a name="line.178"></a> |
| <FONT color="green">179</FONT> * &nbsp; NDC.setMaxDepth(depth);<a name="line.179"></a> |
| <FONT color="green">180</FONT> * }<a name="line.180"></a> |
| <FONT color="green">181</FONT> * </pre><a name="line.181"></a> |
| <FONT color="green">182</FONT> * <p/><a name="line.182"></a> |
| <FONT color="green">183</FONT> * ensures that between the entry and exit of foo the depth of the<a name="line.183"></a> |
| <FONT color="green">184</FONT> * diagnostic stack is conserved.<a name="line.184"></a> |
| <FONT color="green">185</FONT> *<a name="line.185"></a> |
| <FONT color="green">186</FONT> * @see #getDepth<a name="line.186"></a> |
| <FONT color="green">187</FONT> * @param maxDepth The maximum depth of the stack.<a name="line.187"></a> |
| <FONT color="green">188</FONT> */<a name="line.188"></a> |
| <FONT color="green">189</FONT> public static void setMaxDepth(int maxDepth) {<a name="line.189"></a> |
| <FONT color="green">190</FONT> org.apache.logging.log4j.ThreadContext.setMaxDepth(maxDepth);<a name="line.190"></a> |
| <FONT color="green">191</FONT> }<a name="line.191"></a> |
| <FONT color="green">192</FONT> }<a name="line.192"></a> |
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