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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> <a name="line.17"></a> |
| <FONT color="green">018</FONT> package org.apache.logging.log4j;<a name="line.18"></a> |
| <FONT color="green">019</FONT> <a name="line.19"></a> |
| <FONT color="green">020</FONT> import java.io.Serializable;<a name="line.20"></a> |
| <FONT color="green">021</FONT> import java.util.ArrayList;<a name="line.21"></a> |
| <FONT color="green">022</FONT> import java.util.Collection;<a name="line.22"></a> |
| <FONT color="green">023</FONT> import java.util.HashMap;<a name="line.23"></a> |
| <FONT color="green">024</FONT> import java.util.List;<a name="line.24"></a> |
| <FONT color="green">025</FONT> import java.util.Map;<a name="line.25"></a> |
| <FONT color="green">026</FONT> import java.util.NoSuchElementException;<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> * The ThreadContext allows applications to store information either in a Map<a name="line.29"></a> |
| <FONT color="green">030</FONT> * <p/><a name="line.30"></a> |
| <FONT color="green">031</FONT> * <p><b><em>The MDC is managed on a per thread basis</em></b>. A<a name="line.31"></a> |
| <FONT color="green">032</FONT> * child thread automatically inherits a <em>copy</em> of the mapped<a name="line.32"></a> |
| <FONT color="green">033</FONT> * diagnostic context of its parent.<a name="line.33"></a> |
| <FONT color="green">034</FONT> */<a name="line.34"></a> |
| <FONT color="green">035</FONT> public final class ThreadContext {<a name="line.35"></a> |
| <FONT color="green">036</FONT> <a name="line.36"></a> |
| <FONT color="green">037</FONT> /**<a name="line.37"></a> |
| <FONT color="green">038</FONT> * Empty, immutable Map.<a name="line.38"></a> |
| <FONT color="green">039</FONT> */<a name="line.39"></a> |
| <FONT color="green">040</FONT> public static final Map<String, String> EMPTY_MAP = new ImmutableMap();<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> * Empty, immutable ContextStack.<a name="line.43"></a> |
| <FONT color="green">044</FONT> */<a name="line.44"></a> |
| <FONT color="green">045</FONT> public static final ContextStack EMPTY_STACK = new ImmutableStack();<a name="line.45"></a> |
| <FONT color="green">046</FONT> <a name="line.46"></a> |
| <FONT color="green">047</FONT> private static final String DISABLE_MAP = "disableThreadContextMap";<a name="line.47"></a> |
| <FONT color="green">048</FONT> <a name="line.48"></a> |
| <FONT color="green">049</FONT> private static final String DISABLE_STACK = "disableThreadContextStack";<a name="line.49"></a> |
| <FONT color="green">050</FONT> <a name="line.50"></a> |
| <FONT color="green">051</FONT> private static final String DISABLE_ALL = "disableThreadContext";<a name="line.51"></a> |
| <FONT color="green">052</FONT> <a name="line.52"></a> |
| <FONT color="green">053</FONT> private static boolean all = Boolean.getBoolean(DISABLE_ALL);<a name="line.53"></a> |
| <FONT color="green">054</FONT> <a name="line.54"></a> |
| <FONT color="green">055</FONT> private static boolean useMap = !(Boolean.getBoolean(DISABLE_MAP) || all);<a name="line.55"></a> |
| <FONT color="green">056</FONT> <a name="line.56"></a> |
| <FONT color="green">057</FONT> private static boolean useStack = !(Boolean.getBoolean(DISABLE_STACK) || all);<a name="line.57"></a> |
| <FONT color="green">058</FONT> <a name="line.58"></a> |
| <FONT color="green">059</FONT> private static ThreadLocal<Map<String, String>> localMap =<a name="line.59"></a> |
| <FONT color="green">060</FONT> new InheritableThreadLocal<Map<String, String>>() {<a name="line.60"></a> |
| <FONT color="green">061</FONT> @Override<a name="line.61"></a> |
| <FONT color="green">062</FONT> protected Map<String, String> childValue(Map<String, String> parentValue) {<a name="line.62"></a> |
| <FONT color="green">063</FONT> return parentValue == null || !useMap ? null : new HashMap<String, String>(parentValue);<a name="line.63"></a> |
| <FONT color="green">064</FONT> }<a name="line.64"></a> |
| <FONT color="green">065</FONT> };<a name="line.65"></a> |
| <FONT color="green">066</FONT> <a name="line.66"></a> |
| <FONT color="green">067</FONT> private static ThreadLocal<ContextStack> localStack = new ThreadLocal<ContextStack>();<a name="line.67"></a> |
| <FONT color="green">068</FONT> <a name="line.68"></a> |
| <FONT color="green">069</FONT> private ThreadContext() {<a name="line.69"></a> |
| <FONT color="green">070</FONT> <a name="line.70"></a> |
| <FONT color="green">071</FONT> }<a name="line.71"></a> |
| <FONT color="green">072</FONT> <a name="line.72"></a> |
| <FONT color="green">073</FONT> /**<a name="line.73"></a> |
| <FONT color="green">074</FONT> * Put a context value (the <code>o</code> parameter) as identified<a name="line.74"></a> |
| <FONT color="green">075</FONT> * with the <code>key</code> parameter into the current thread's<a name="line.75"></a> |
| <FONT color="green">076</FONT> * context map.<a name="line.76"></a> |
| <FONT color="green">077</FONT> * <p/><a name="line.77"></a> |
| <FONT color="green">078</FONT> * <p>If the current thread does not have a context map it is<a name="line.78"></a> |
| <FONT color="green">079</FONT> * created as a side effect.<a name="line.79"></a> |
| <FONT color="green">080</FONT> * @param key The key name.<a name="line.80"></a> |
| <FONT color="green">081</FONT> * @param value The key value.<a name="line.81"></a> |
| <FONT color="green">082</FONT> */<a name="line.82"></a> |
| <FONT color="green">083</FONT> public static void put(String key, String value) {<a name="line.83"></a> |
| <FONT color="green">084</FONT> if (!useMap) {<a name="line.84"></a> |
| <FONT color="green">085</FONT> return;<a name="line.85"></a> |
| <FONT color="green">086</FONT> }<a name="line.86"></a> |
| <FONT color="green">087</FONT> Map<String, String> map = localMap.get();<a name="line.87"></a> |
| <FONT color="green">088</FONT> if (map == null) {<a name="line.88"></a> |
| <FONT color="green">089</FONT> map = new HashMap<String, String>();<a name="line.89"></a> |
| <FONT color="green">090</FONT> localMap.set(map);<a name="line.90"></a> |
| <FONT color="green">091</FONT> }<a name="line.91"></a> |
| <FONT color="green">092</FONT> map.put(key, value);<a name="line.92"></a> |
| <FONT color="green">093</FONT> }<a name="line.93"></a> |
| <FONT color="green">094</FONT> <a name="line.94"></a> |
| <FONT color="green">095</FONT> /**<a name="line.95"></a> |
| <FONT color="green">096</FONT> * Get the context identified by the <code>key</code> parameter.<a name="line.96"></a> |
| <FONT color="green">097</FONT> * <p/><a name="line.97"></a> |
| <FONT color="green">098</FONT> * <p>This method has no side effects.<a name="line.98"></a> |
| <FONT color="green">099</FONT> * @param key The key to locate.<a name="line.99"></a> |
| <FONT color="green">100</FONT> * @return The value associated with the key or null.<a name="line.100"></a> |
| <FONT color="green">101</FONT> */<a name="line.101"></a> |
| <FONT color="green">102</FONT> public static String get(String key) {<a name="line.102"></a> |
| <FONT color="green">103</FONT> Map<String, String> map = localMap.get();<a name="line.103"></a> |
| <FONT color="green">104</FONT> return map == null ? null : map.get(key);<a name="line.104"></a> |
| <FONT color="green">105</FONT> }<a name="line.105"></a> |
| <FONT color="green">106</FONT> <a name="line.106"></a> |
| <FONT color="green">107</FONT> /**<a name="line.107"></a> |
| <FONT color="green">108</FONT> * Remove the the context identified by the <code>key</code><a name="line.108"></a> |
| <FONT color="green">109</FONT> * parameter.<a name="line.109"></a> |
| <FONT color="green">110</FONT> * @param key The key to remove.<a name="line.110"></a> |
| <FONT color="green">111</FONT> */<a name="line.111"></a> |
| <FONT color="green">112</FONT> public static void remove(String key) {<a name="line.112"></a> |
| <FONT color="green">113</FONT> Map<String, String> map = localMap.get();<a name="line.113"></a> |
| <FONT color="green">114</FONT> if (map != null) {<a name="line.114"></a> |
| <FONT color="green">115</FONT> map.remove(key);<a name="line.115"></a> |
| <FONT color="green">116</FONT> }<a name="line.116"></a> |
| <FONT color="green">117</FONT> }<a name="line.117"></a> |
| <FONT color="green">118</FONT> <a name="line.118"></a> |
| <FONT color="green">119</FONT> /**<a name="line.119"></a> |
| <FONT color="green">120</FONT> * Clear the context.<a name="line.120"></a> |
| <FONT color="green">121</FONT> */<a name="line.121"></a> |
| <FONT color="green">122</FONT> public static void clear() {<a name="line.122"></a> |
| <FONT color="green">123</FONT> localMap.remove();<a name="line.123"></a> |
| <FONT color="green">124</FONT> }<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> * Determine if the key is in the context.<a name="line.127"></a> |
| <FONT color="green">128</FONT> * @param key The key to locate.<a name="line.128"></a> |
| <FONT color="green">129</FONT> * @return True if the key is in the context, false otherwise.<a name="line.129"></a> |
| <FONT color="green">130</FONT> */<a name="line.130"></a> |
| <FONT color="green">131</FONT> public static boolean containsKey(String key) {<a name="line.131"></a> |
| <FONT color="green">132</FONT> Map<String, String> map = localMap.get();<a name="line.132"></a> |
| <FONT color="green">133</FONT> return map == null ? false : map.containsKey(key);<a name="line.133"></a> |
| <FONT color="green">134</FONT> }<a name="line.134"></a> |
| <FONT color="green">135</FONT> <a name="line.135"></a> |
| <FONT color="green">136</FONT> /**<a name="line.136"></a> |
| <FONT color="green">137</FONT> * Get a copy of current thread's context Map.<a name="line.137"></a> |
| <FONT color="green">138</FONT> * @return a copy of the context.<a name="line.138"></a> |
| <FONT color="green">139</FONT> */<a name="line.139"></a> |
| <FONT color="green">140</FONT> public static Map<String, String> getContext() {<a name="line.140"></a> |
| <FONT color="green">141</FONT> Map<String, String> map = localMap.get();<a name="line.141"></a> |
| <FONT color="green">142</FONT> return map == null ? new HashMap<String, String>() : new HashMap<String, String>(map);<a name="line.142"></a> |
| <FONT color="green">143</FONT> }<a name="line.143"></a> |
| <FONT color="green">144</FONT> <a name="line.144"></a> |
| <FONT color="green">145</FONT> /**<a name="line.145"></a> |
| <FONT color="green">146</FONT> * Get an immutable copy of the current thread's context Map.<a name="line.146"></a> |
| <FONT color="green">147</FONT> * @return An immutable copy of the ThreadContext Map.<a name="line.147"></a> |
| <FONT color="green">148</FONT> */<a name="line.148"></a> |
| <FONT color="green">149</FONT> public static Map<String, String> getImmutableContext() {<a name="line.149"></a> |
| <FONT color="green">150</FONT> Map<String, String> map = localMap.get();<a name="line.150"></a> |
| <FONT color="green">151</FONT> return map == null ? new ImmutableMap() : new ImmutableMap(map);<a name="line.151"></a> |
| <FONT color="green">152</FONT> }<a name="line.152"></a> |
| <FONT color="green">153</FONT> <a name="line.153"></a> |
| <FONT color="green">154</FONT> /**<a name="line.154"></a> |
| <FONT color="green">155</FONT> * Return true if the Map is empty.<a name="line.155"></a> |
| <FONT color="green">156</FONT> * @return true if the Map is empty, false otherwise.<a name="line.156"></a> |
| <FONT color="green">157</FONT> */<a name="line.157"></a> |
| <FONT color="green">158</FONT> public static boolean isEmpty() {<a name="line.158"></a> |
| <FONT color="green">159</FONT> Map<String, String> map = localMap.get();<a name="line.159"></a> |
| <FONT color="green">160</FONT> return map == null || map.size() == 0;<a name="line.160"></a> |
| <FONT color="green">161</FONT> }<a name="line.161"></a> |
| <FONT color="green">162</FONT> <a name="line.162"></a> |
| <FONT color="green">163</FONT> /**<a name="line.163"></a> |
| <FONT color="green">164</FONT> * Clear the stack for this thread.<a name="line.164"></a> |
| <FONT color="green">165</FONT> */<a name="line.165"></a> |
| <FONT color="green">166</FONT> public static void clearStack() {<a name="line.166"></a> |
| <FONT color="green">167</FONT> localStack.remove();<a name="line.167"></a> |
| <FONT color="green">168</FONT> }<a name="line.168"></a> |
| <FONT color="green">169</FONT> <a name="line.169"></a> |
| <FONT color="green">170</FONT> /**<a name="line.170"></a> |
| <FONT color="green">171</FONT> * Return a copy of this thread's stack.<a name="line.171"></a> |
| <FONT color="green">172</FONT> * @return A copy of this thread's stack.<a name="line.172"></a> |
| <FONT color="green">173</FONT> */<a name="line.173"></a> |
| <FONT color="green">174</FONT> public static ContextStack cloneStack() {<a name="line.174"></a> |
| <FONT color="green">175</FONT> ContextStack stack = localStack.get();<a name="line.175"></a> |
| <FONT color="green">176</FONT> return stack == null ? new ThreadContextStack() : new ThreadContextStack(stack.asList());<a name="line.176"></a> |
| <FONT color="green">177</FONT> }<a name="line.177"></a> |
| <FONT color="green">178</FONT> <a name="line.178"></a> |
| <FONT color="green">179</FONT> /**<a name="line.179"></a> |
| <FONT color="green">180</FONT> * Get an immutable copy of this current thread's context stack.<a name="line.180"></a> |
| <FONT color="green">181</FONT> * @return an immutable copy of the ThreadContext stack.<a name="line.181"></a> |
| <FONT color="green">182</FONT> */<a name="line.182"></a> |
| <FONT color="green">183</FONT> public static ContextStack getImmutableStack() {<a name="line.183"></a> |
| <FONT color="green">184</FONT> ContextStack stack = localStack.get();<a name="line.184"></a> |
| <FONT color="green">185</FONT> return stack == null ? EMPTY_STACK : new ImmutableStack(stack.asList());<a name="line.185"></a> |
| <FONT color="green">186</FONT> }<a name="line.186"></a> |
| <FONT color="green">187</FONT> <a name="line.187"></a> |
| <FONT color="green">188</FONT> /**<a name="line.188"></a> |
| <FONT color="green">189</FONT> * Set this thread's stack.<a name="line.189"></a> |
| <FONT color="green">190</FONT> * @param stack The stack to use.<a name="line.190"></a> |
| <FONT color="green">191</FONT> */<a name="line.191"></a> |
| <FONT color="green">192</FONT> public static void setStack(Collection<String> stack) {<a name="line.192"></a> |
| <FONT color="green">193</FONT> if (stack.size() == 0 || !useStack) {<a name="line.193"></a> |
| <FONT color="green">194</FONT> return;<a name="line.194"></a> |
| <FONT color="green">195</FONT> }<a name="line.195"></a> |
| <FONT color="green">196</FONT> localStack.set(new ThreadContextStack(stack));<a name="line.196"></a> |
| <FONT color="green">197</FONT> }<a name="line.197"></a> |
| <FONT color="green">198</FONT> <a name="line.198"></a> |
| <FONT color="green">199</FONT> /**<a name="line.199"></a> |
| <FONT color="green">200</FONT> * Get the current nesting depth of this thread's stack.<a name="line.200"></a> |
| <FONT color="green">201</FONT> * @return the number of items in the stack.<a name="line.201"></a> |
| <FONT color="green">202</FONT> *<a name="line.202"></a> |
| <FONT color="green">203</FONT> * @see #trim<a name="line.203"></a> |
| <FONT color="green">204</FONT> */<a name="line.204"></a> |
| <FONT color="green">205</FONT> public static int getDepth() {<a name="line.205"></a> |
| <FONT color="green">206</FONT> ContextStack stack = localStack.get();<a name="line.206"></a> |
| <FONT color="green">207</FONT> return stack == null ? 0 : stack.getDepth();<a name="line.207"></a> |
| <FONT color="green">208</FONT> }<a name="line.208"></a> |
| <FONT color="green">209</FONT> <a name="line.209"></a> |
| <FONT color="green">210</FONT> /**<a name="line.210"></a> |
| <FONT color="green">211</FONT> * Returns the value of the last item placed on the stack.<a name="line.211"></a> |
| <FONT color="green">212</FONT> * <p/><a name="line.212"></a> |
| <FONT color="green">213</FONT> * <p>The returned value is the value that was pushed last. If no<a name="line.213"></a> |
| <FONT color="green">214</FONT> * context is available, then the empty string "" is returned.<a name="line.214"></a> |
| <FONT color="green">215</FONT> *<a name="line.215"></a> |
| <FONT color="green">216</FONT> * @return String The innermost diagnostic context.<a name="line.216"></a> |
| <FONT color="green">217</FONT> */<a name="line.217"></a> |
| <FONT color="green">218</FONT> public static String pop() {<a name="line.218"></a> |
| <FONT color="green">219</FONT> ContextStack s = localStack.get();<a name="line.219"></a> |
| <FONT color="green">220</FONT> if (s == null || s.getDepth() == 0) {<a name="line.220"></a> |
| <FONT color="green">221</FONT> return "";<a name="line.221"></a> |
| <FONT color="green">222</FONT> }<a name="line.222"></a> |
| <FONT color="green">223</FONT> return s.pop();<a name="line.223"></a> |
| <FONT color="green">224</FONT> }<a name="line.224"></a> |
| <FONT color="green">225</FONT> <a name="line.225"></a> |
| <FONT color="green">226</FONT> /**<a name="line.226"></a> |
| <FONT color="green">227</FONT> * Looks at the last diagnostic context at the top of this NDC<a name="line.227"></a> |
| <FONT color="green">228</FONT> * without removing it.<a name="line.228"></a> |
| <FONT color="green">229</FONT> * <p/><a name="line.229"></a> |
| <FONT color="green">230</FONT> * <p>The returned value is the value that was pushed last. If no<a name="line.230"></a> |
| <FONT color="green">231</FONT> * context is available, then the empty string "" is returned.<a name="line.231"></a> |
| <FONT color="green">232</FONT> *<a name="line.232"></a> |
| <FONT color="green">233</FONT> * @return String The innermost diagnostic context.<a name="line.233"></a> |
| <FONT color="green">234</FONT> */<a name="line.234"></a> |
| <FONT color="green">235</FONT> public static String peek() {<a name="line.235"></a> |
| <FONT color="green">236</FONT> ContextStack s = localStack.get();<a name="line.236"></a> |
| <FONT color="green">237</FONT> if (s == null || s.getDepth() == 0) {<a name="line.237"></a> |
| <FONT color="green">238</FONT> return "";<a name="line.238"></a> |
| <FONT color="green">239</FONT> }<a name="line.239"></a> |
| <FONT color="green">240</FONT> return s.peek();<a name="line.240"></a> |
| <FONT color="green">241</FONT> }<a name="line.241"></a> |
| <FONT color="green">242</FONT> <a name="line.242"></a> |
| <FONT color="green">243</FONT> /**<a name="line.243"></a> |
| <FONT color="green">244</FONT> * Push new diagnostic context information for the current thread.<a name="line.244"></a> |
| <FONT color="green">245</FONT> * <p/><a name="line.245"></a> |
| <FONT color="green">246</FONT> * <p>The contents of the <code>message</code> parameter is<a name="line.246"></a> |
| <FONT color="green">247</FONT> * determined solely by the client.<a name="line.247"></a> |
| <FONT color="green">248</FONT> *<a name="line.248"></a> |
| <FONT color="green">249</FONT> * @param message The new diagnostic context information.<a name="line.249"></a> |
| <FONT color="green">250</FONT> */<a name="line.250"></a> |
| <FONT color="green">251</FONT> public static void push(String message) {<a name="line.251"></a> |
| <FONT color="green">252</FONT> if (!useStack) {<a name="line.252"></a> |
| <FONT color="green">253</FONT> return;<a name="line.253"></a> |
| <FONT color="green">254</FONT> }<a name="line.254"></a> |
| <FONT color="green">255</FONT> ContextStack stack = localStack.get();<a name="line.255"></a> |
| <FONT color="green">256</FONT> if (stack == null) {<a name="line.256"></a> |
| <FONT color="green">257</FONT> stack = new ThreadContextStack();<a name="line.257"></a> |
| <FONT color="green">258</FONT> localStack.set(stack);<a name="line.258"></a> |
| <FONT color="green">259</FONT> }<a name="line.259"></a> |
| <FONT color="green">260</FONT> stack.push(message);<a name="line.260"></a> |
| <FONT color="green">261</FONT> }<a name="line.261"></a> |
| <FONT color="green">262</FONT> <a name="line.262"></a> |
| <FONT color="green">263</FONT> /**<a name="line.263"></a> |
| <FONT color="green">264</FONT> * Remove the diagnostic context for this thread.<a name="line.264"></a> |
| <FONT color="green">265</FONT> * <p/><a name="line.265"></a> |
| <FONT color="green">266</FONT> * <p>Each thread that created a diagnostic context by calling<a name="line.266"></a> |
| <FONT color="green">267</FONT> * {@link #push} should call this method before exiting. Otherwise,<a name="line.267"></a> |
| <FONT color="green">268</FONT> * the memory used by the <b>thread</b> cannot be reclaimed by the<a name="line.268"></a> |
| <FONT color="green">269</FONT> * VM.<a name="line.269"></a> |
| <FONT color="green">270</FONT> * <p/><a name="line.270"></a> |
| <FONT color="green">271</FONT> * <p>As this is such an important problem in heavy duty systems and<a name="line.271"></a> |
| <FONT color="green">272</FONT> * because it is difficult to always guarantee that the remove<a name="line.272"></a> |
| <FONT color="green">273</FONT> * method is called before exiting a thread, this method has been<a name="line.273"></a> |
| <FONT color="green">274</FONT> * augmented to lazily remove references to dead threads. In<a name="line.274"></a> |
| <FONT color="green">275</FONT> * practice, this means that you can be a little sloppy and<a name="line.275"></a> |
| <FONT color="green">276</FONT> * occasionally forget to call {@link #remove} before exiting a<a name="line.276"></a> |
| <FONT color="green">277</FONT> * thread. However, you must call <code>remove</code> sometime. If<a name="line.277"></a> |
| <FONT color="green">278</FONT> * you never call it, then your application is sure to run out of<a name="line.278"></a> |
| <FONT color="green">279</FONT> * memory.<a name="line.279"></a> |
| <FONT color="green">280</FONT> */<a name="line.280"></a> |
| <FONT color="green">281</FONT> public static void removeStack() {<a name="line.281"></a> |
| <FONT color="green">282</FONT> localStack.remove();<a name="line.282"></a> |
| <FONT color="green">283</FONT> }<a name="line.283"></a> |
| <FONT color="green">284</FONT> <a name="line.284"></a> |
| <FONT color="green">285</FONT> /**<a name="line.285"></a> |
| <FONT color="green">286</FONT> * Trims elements from this diagnostic context. If the current<a name="line.286"></a> |
| <FONT color="green">287</FONT> * depth is smaller or equal to <code>maxDepth</code>, then no<a name="line.287"></a> |
| <FONT color="green">288</FONT> * action is taken. If the current depth is larger than newDepth<a name="line.288"></a> |
| <FONT color="green">289</FONT> * then all elements at maxDepth or higher are discarded.<a name="line.289"></a> |
| <FONT color="green">290</FONT> * <p/><a name="line.290"></a> |
| <FONT color="green">291</FONT> * <p>This method is a convenient alternative to multiple {@link<a name="line.291"></a> |
| <FONT color="green">292</FONT> * #pop} calls. Moreover, it is often the case that at the end of<a name="line.292"></a> |
| <FONT color="green">293</FONT> * complex call sequences, the depth of the ThreadContext is<a name="line.293"></a> |
| <FONT color="green">294</FONT> * unpredictable. The <code>trim</code> method circumvents<a name="line.294"></a> |
| <FONT color="green">295</FONT> * this problem.<a name="line.295"></a> |
| <FONT color="green">296</FONT> * <p/><a name="line.296"></a> |
| <FONT color="green">297</FONT> * <p>For example, the combination<a name="line.297"></a> |
| <FONT color="green">298</FONT> * <pre><a name="line.298"></a> |
| <FONT color="green">299</FONT> * void foo() {<a name="line.299"></a> |
| <FONT color="green">300</FONT> * &nbsp; int depth = ThreadContext.getDepth();<a name="line.300"></a> |
| <FONT color="green">301</FONT> * <p/><a name="line.301"></a> |
| <FONT color="green">302</FONT> * &nbsp; ... complex sequence of calls<a name="line.302"></a> |
| <FONT color="green">303</FONT> * <p/><a name="line.303"></a> |
| <FONT color="green">304</FONT> * &nbsp; ThreadContext.trim(depth);<a name="line.304"></a> |
| <FONT color="green">305</FONT> * }<a name="line.305"></a> |
| <FONT color="green">306</FONT> * </pre><a name="line.306"></a> |
| <FONT color="green">307</FONT> * <p/><a name="line.307"></a> |
| <FONT color="green">308</FONT> * ensures that between the entry and exit of foo the depth of the<a name="line.308"></a> |
| <FONT color="green">309</FONT> * diagnostic stack is conserved.<a name="line.309"></a> |
| <FONT color="green">310</FONT> *<a name="line.310"></a> |
| <FONT color="green">311</FONT> * @see #getDepth<a name="line.311"></a> |
| <FONT color="green">312</FONT> * @param depth The number of elements to keep.<a name="line.312"></a> |
| <FONT color="green">313</FONT> */<a name="line.313"></a> |
| <FONT color="green">314</FONT> public static void trim(int depth) {<a name="line.314"></a> |
| <FONT color="green">315</FONT> ContextStack stack = localStack.get();<a name="line.315"></a> |
| <FONT color="green">316</FONT> if (stack != null) {<a name="line.316"></a> |
| <FONT color="green">317</FONT> stack.trim(depth);<a name="line.317"></a> |
| <FONT color="green">318</FONT> }<a name="line.318"></a> |
| <FONT color="green">319</FONT> }<a name="line.319"></a> |
| <FONT color="green">320</FONT> <a name="line.320"></a> |
| <FONT color="green">321</FONT> /**<a name="line.321"></a> |
| <FONT color="green">322</FONT> * The ThreadContext Stack interface.<a name="line.322"></a> |
| <FONT color="green">323</FONT> */<a name="line.323"></a> |
| <FONT color="green">324</FONT> public interface ContextStack extends Serializable {<a name="line.324"></a> |
| <FONT color="green">325</FONT> <a name="line.325"></a> |
| <FONT color="green">326</FONT> /**<a name="line.326"></a> |
| <FONT color="green">327</FONT> * Clears all elements from the stack.<a name="line.327"></a> |
| <FONT color="green">328</FONT> */<a name="line.328"></a> |
| <FONT color="green">329</FONT> void clear();<a name="line.329"></a> |
| <FONT color="green">330</FONT> <a name="line.330"></a> |
| <FONT color="green">331</FONT> /**<a name="line.331"></a> |
| <FONT color="green">332</FONT> * Return the element at the top of the stack.<a name="line.332"></a> |
| <FONT color="green">333</FONT> * @return The element at the top of the stack.<a name="line.333"></a> |
| <FONT color="green">334</FONT> * @throws java.util.NoSuchElementException if the stack is empty.<a name="line.334"></a> |
| <FONT color="green">335</FONT> */<a name="line.335"></a> |
| <FONT color="green">336</FONT> String pop();<a name="line.336"></a> |
| <FONT color="green">337</FONT> <a name="line.337"></a> |
| <FONT color="green">338</FONT> /**<a name="line.338"></a> |
| <FONT color="green">339</FONT> * Return the element at the top of the stack without removing it or null if the stack is empty.<a name="line.339"></a> |
| <FONT color="green">340</FONT> * @return the element at the top of the stack or null if the stack is empty.<a name="line.340"></a> |
| <FONT color="green">341</FONT> */<a name="line.341"></a> |
| <FONT color="green">342</FONT> String peek();<a name="line.342"></a> |
| <FONT color="green">343</FONT> <a name="line.343"></a> |
| <FONT color="green">344</FONT> /**<a name="line.344"></a> |
| <FONT color="green">345</FONT> * Add an element to the stack.<a name="line.345"></a> |
| <FONT color="green">346</FONT> * @param message The element to add.<a name="line.346"></a> |
| <FONT color="green">347</FONT> */<a name="line.347"></a> |
| <FONT color="green">348</FONT> void push(String message);<a name="line.348"></a> |
| <FONT color="green">349</FONT> <a name="line.349"></a> |
| <FONT color="green">350</FONT> /**<a name="line.350"></a> |
| <FONT color="green">351</FONT> * Return the number of elements in the stack.<a name="line.351"></a> |
| <FONT color="green">352</FONT> * @return the number of elements in the stack.<a name="line.352"></a> |
| <FONT color="green">353</FONT> */<a name="line.353"></a> |
| <FONT color="green">354</FONT> int getDepth();<a name="line.354"></a> |
| <FONT color="green">355</FONT> <a name="line.355"></a> |
| <FONT color="green">356</FONT> /**<a name="line.356"></a> |
| <FONT color="green">357</FONT> * Returns all the elements in the stack in a List.<a name="line.357"></a> |
| <FONT color="green">358</FONT> * @return all the elements in the stack in a List.<a name="line.358"></a> |
| <FONT color="green">359</FONT> */<a name="line.359"></a> |
| <FONT color="green">360</FONT> List<String> asList();<a name="line.360"></a> |
| <FONT color="green">361</FONT> <a name="line.361"></a> |
| <FONT color="green">362</FONT> /**<a name="line.362"></a> |
| <FONT color="green">363</FONT> * Trims elements from the end of the stack.<a name="line.363"></a> |
| <FONT color="green">364</FONT> * @param depth The maximum number of items in the stack to keep.<a name="line.364"></a> |
| <FONT color="green">365</FONT> */<a name="line.365"></a> |
| <FONT color="green">366</FONT> void trim(int depth);<a name="line.366"></a> |
| <FONT color="green">367</FONT> <a name="line.367"></a> |
| <FONT color="green">368</FONT> /**<a name="line.368"></a> |
| <FONT color="green">369</FONT> * Returns a copy of the ContextStack.<a name="line.369"></a> |
| <FONT color="green">370</FONT> * @return a copy of the ContextStack.<a name="line.370"></a> |
| <FONT color="green">371</FONT> */<a name="line.371"></a> |
| <FONT color="green">372</FONT> ContextStack copy();<a name="line.372"></a> |
| <FONT color="green">373</FONT> }<a name="line.373"></a> |
| <FONT color="green">374</FONT> <a name="line.374"></a> |
| <FONT color="green">375</FONT> /**<a name="line.375"></a> |
| <FONT color="green">376</FONT> * The ContextStack implementation.<a name="line.376"></a> |
| <FONT color="green">377</FONT> */<a name="line.377"></a> |
| <FONT color="green">378</FONT> private static class ThreadContextStack extends ArrayList<String> implements ContextStack {<a name="line.378"></a> |
| <FONT color="green">379</FONT> <a name="line.379"></a> |
| <FONT color="green">380</FONT> private static final long serialVersionUID = 5050501L;<a name="line.380"></a> |
| <FONT color="green">381</FONT> <a name="line.381"></a> |
| <FONT color="green">382</FONT> public ThreadContextStack() {<a name="line.382"></a> |
| <FONT color="green">383</FONT> super();<a name="line.383"></a> |
| <FONT color="green">384</FONT> }<a name="line.384"></a> |
| <FONT color="green">385</FONT> <a name="line.385"></a> |
| <FONT color="green">386</FONT> public ThreadContextStack(Collection<String> collection) {<a name="line.386"></a> |
| <FONT color="green">387</FONT> super(collection);<a name="line.387"></a> |
| <FONT color="green">388</FONT> }<a name="line.388"></a> |
| <FONT color="green">389</FONT> <a name="line.389"></a> |
| <FONT color="green">390</FONT> public String pop() {<a name="line.390"></a> |
| <FONT color="green">391</FONT> int index = size() - 1;<a name="line.391"></a> |
| <FONT color="green">392</FONT> if (index >= 0) {<a name="line.392"></a> |
| <FONT color="green">393</FONT> String result = get(index);<a name="line.393"></a> |
| <FONT color="green">394</FONT> remove(index);<a name="line.394"></a> |
| <FONT color="green">395</FONT> return result;<a name="line.395"></a> |
| <FONT color="green">396</FONT> }<a name="line.396"></a> |
| <FONT color="green">397</FONT> throw new NoSuchElementException("The ThreadContext stack is empty");<a name="line.397"></a> |
| <FONT color="green">398</FONT> }<a name="line.398"></a> |
| <FONT color="green">399</FONT> <a name="line.399"></a> |
| <FONT color="green">400</FONT> public String peek() {<a name="line.400"></a> |
| <FONT color="green">401</FONT> int index = size() - 1;<a name="line.401"></a> |
| <FONT color="green">402</FONT> if (index >= 0) {<a name="line.402"></a> |
| <FONT color="green">403</FONT> return get(index);<a name="line.403"></a> |
| <FONT color="green">404</FONT> }<a name="line.404"></a> |
| <FONT color="green">405</FONT> return null;<a name="line.405"></a> |
| <FONT color="green">406</FONT> }<a name="line.406"></a> |
| <FONT color="green">407</FONT> <a name="line.407"></a> |
| <FONT color="green">408</FONT> public void push(String message) {<a name="line.408"></a> |
| <FONT color="green">409</FONT> add(message);<a name="line.409"></a> |
| <FONT color="green">410</FONT> }<a name="line.410"></a> |
| <FONT color="green">411</FONT> <a name="line.411"></a> |
| <FONT color="green">412</FONT> public int getDepth() {<a name="line.412"></a> |
| <FONT color="green">413</FONT> return size();<a name="line.413"></a> |
| <FONT color="green">414</FONT> }<a name="line.414"></a> |
| <FONT color="green">415</FONT> <a name="line.415"></a> |
| <FONT color="green">416</FONT> public List<String> asList() {<a name="line.416"></a> |
| <FONT color="green">417</FONT> return this;<a name="line.417"></a> |
| <FONT color="green">418</FONT> }<a name="line.418"></a> |
| <FONT color="green">419</FONT> <a name="line.419"></a> |
| <FONT color="green">420</FONT> public void trim(int depth) {<a name="line.420"></a> |
| <FONT color="green">421</FONT> if (depth < 0) {<a name="line.421"></a> |
| <FONT color="green">422</FONT> throw new IllegalArgumentException("Maximum stack depth cannot be negative");<a name="line.422"></a> |
| <FONT color="green">423</FONT> }<a name="line.423"></a> |
| <FONT color="green">424</FONT> while (size() > depth) {<a name="line.424"></a> |
| <FONT color="green">425</FONT> remove(size() - 1);<a name="line.425"></a> |
| <FONT color="green">426</FONT> }<a name="line.426"></a> |
| <FONT color="green">427</FONT> <a name="line.427"></a> |
| <FONT color="green">428</FONT> }<a name="line.428"></a> |
| <FONT color="green">429</FONT> <a name="line.429"></a> |
| <FONT color="green">430</FONT> public ContextStack copy() {<a name="line.430"></a> |
| <FONT color="green">431</FONT> return new ThreadContextStack(this);<a name="line.431"></a> |
| <FONT color="green">432</FONT> }<a name="line.432"></a> |
| <FONT color="green">433</FONT> }<a name="line.433"></a> |
| <FONT color="green">434</FONT> <a name="line.434"></a> |
| <FONT color="green">435</FONT> /**<a name="line.435"></a> |
| <FONT color="green">436</FONT> * An immutable ContextStack.<a name="line.436"></a> |
| <FONT color="green">437</FONT> */<a name="line.437"></a> |
| <FONT color="green">438</FONT> private static class ImmutableStack extends ThreadContextStack {<a name="line.438"></a> |
| <FONT color="green">439</FONT> <a name="line.439"></a> |
| <FONT color="green">440</FONT> private static final long serialVersionUID = 5050502L;<a name="line.440"></a> |
| <FONT color="green">441</FONT> <a name="line.441"></a> |
| <FONT color="green">442</FONT> public ImmutableStack() {<a name="line.442"></a> |
| <FONT color="green">443</FONT> }<a name="line.443"></a> |
| <FONT color="green">444</FONT> <a name="line.444"></a> |
| <FONT color="green">445</FONT> public ImmutableStack(Collection<String> collection) {<a name="line.445"></a> |
| <FONT color="green">446</FONT> super(collection);<a name="line.446"></a> |
| <FONT color="green">447</FONT> }<a name="line.447"></a> |
| <FONT color="green">448</FONT> <a name="line.448"></a> |
| <FONT color="green">449</FONT> public ImmutableStack(ThreadContextStack stack) {<a name="line.449"></a> |
| <FONT color="green">450</FONT> super(stack);<a name="line.450"></a> |
| <FONT color="green">451</FONT> }<a name="line.451"></a> |
| <FONT color="green">452</FONT> <a name="line.452"></a> |
| <FONT color="green">453</FONT> @Override<a name="line.453"></a> |
| <FONT color="green">454</FONT> public void push(String message) {<a name="line.454"></a> |
| <FONT color="green">455</FONT> throw new UnsupportedOperationException("Stack cannot be modified");<a name="line.455"></a> |
| <FONT color="green">456</FONT> }<a name="line.456"></a> |
| <FONT color="green">457</FONT> <a name="line.457"></a> |
| <FONT color="green">458</FONT> @Override<a name="line.458"></a> |
| <FONT color="green">459</FONT> public void trim(int depth) {<a name="line.459"></a> |
| <FONT color="green">460</FONT> throw new UnsupportedOperationException("Stack cannot be modified");<a name="line.460"></a> |
| <FONT color="green">461</FONT> }<a name="line.461"></a> |
| <FONT color="green">462</FONT> }<a name="line.462"></a> |
| <FONT color="green">463</FONT> <a name="line.463"></a> |
| <FONT color="green">464</FONT> /**<a name="line.464"></a> |
| <FONT color="green">465</FONT> * An immutable Context Map.<a name="line.465"></a> |
| <FONT color="green">466</FONT> */<a name="line.466"></a> |
| <FONT color="green">467</FONT> private static class ImmutableMap extends HashMap<String, String> {<a name="line.467"></a> |
| <FONT color="green">468</FONT> private static final long serialVersionUID = 5050503L;<a name="line.468"></a> |
| <FONT color="green">469</FONT> <a name="line.469"></a> |
| <FONT color="green">470</FONT> public ImmutableMap() {<a name="line.470"></a> |
| <FONT color="green">471</FONT> super();<a name="line.471"></a> |
| <FONT color="green">472</FONT> }<a name="line.472"></a> |
| <FONT color="green">473</FONT> <a name="line.473"></a> |
| <FONT color="green">474</FONT> public ImmutableMap(Map<String, String> map) {<a name="line.474"></a> |
| <FONT color="green">475</FONT> super(map);<a name="line.475"></a> |
| <FONT color="green">476</FONT> }<a name="line.476"></a> |
| <FONT color="green">477</FONT> <a name="line.477"></a> |
| <FONT color="green">478</FONT> @Override<a name="line.478"></a> |
| <FONT color="green">479</FONT> public String put(String s, String s1) {<a name="line.479"></a> |
| <FONT color="green">480</FONT> throw new UnsupportedOperationException("Map cannot be modified");<a name="line.480"></a> |
| <FONT color="green">481</FONT> }<a name="line.481"></a> |
| <FONT color="green">482</FONT> <a name="line.482"></a> |
| <FONT color="green">483</FONT> @Override<a name="line.483"></a> |
| <FONT color="green">484</FONT> public void putAll(Map<? extends String, ? extends String> map) {<a name="line.484"></a> |
| <FONT color="green">485</FONT> throw new UnsupportedOperationException("Map cannot be modified");<a name="line.485"></a> |
| <FONT color="green">486</FONT> }<a name="line.486"></a> |
| <FONT color="green">487</FONT> <a name="line.487"></a> |
| <FONT color="green">488</FONT> @Override<a name="line.488"></a> |
| <FONT color="green">489</FONT> public String remove(Object o) {<a name="line.489"></a> |
| <FONT color="green">490</FONT> throw new UnsupportedOperationException("Map cannot be modified");<a name="line.490"></a> |
| <FONT color="green">491</FONT> }<a name="line.491"></a> |
| <FONT color="green">492</FONT> <a name="line.492"></a> |
| <FONT color="green">493</FONT> @Override<a name="line.493"></a> |
| <FONT color="green">494</FONT> public void clear() {<a name="line.494"></a> |
| <FONT color="green">495</FONT> throw new UnsupportedOperationException("Map cannot be modified");<a name="line.495"></a> |
| <FONT color="green">496</FONT> }<a name="line.496"></a> |
| <FONT color="green">497</FONT> }<a name="line.497"></a> |
| <FONT color="green">498</FONT> }<a name="line.498"></a> |
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