Google Git
Sign in
apache / hbase-site / a2a1a96078a496964bd779adfa357135655a68bc / . / devapidocs / src-html / org / apache / hadoop / hbase / util / DynamicClassLoader.html
blob: 07dabccdafada74621a56178da2c7280b5685a64 [file] [log] [blame]
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html lang="en">
<head>
<title>Source code</title>
<link rel="stylesheet" type="text/css" href="../../../../../../stylesheet.css" title="Style">
</head>
<body>
<div class="sourceContainer">
<pre><span class="sourceLineNo">001</span>/*<a name="line.1"></a>
<span class="sourceLineNo">002</span> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
<span class="sourceLineNo">003</span> * or more contributor license agreements. See the NOTICE file<a name="line.3"></a>
<span class="sourceLineNo">004</span> * distributed with this work for additional information<a name="line.4"></a>
<span class="sourceLineNo">005</span> * regarding copyright ownership. The ASF licenses this file<a name="line.5"></a>
<span class="sourceLineNo">006</span> * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
<span class="sourceLineNo">007</span> * "License"); you may not use this file except in compliance<a name="line.7"></a>
<span class="sourceLineNo">008</span> * with the License. You may obtain a copy of the License at<a name="line.8"></a>
<span class="sourceLineNo">009</span> *<a name="line.9"></a>
<span class="sourceLineNo">010</span> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
<span class="sourceLineNo">011</span> *<a name="line.11"></a>
<span class="sourceLineNo">012</span> * Unless required by applicable law or agreed to in writing, software<a name="line.12"></a>
<span class="sourceLineNo">013</span> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.13"></a>
<span class="sourceLineNo">014</span> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.14"></a>
<span class="sourceLineNo">015</span> * See the License for the specific language governing permissions and<a name="line.15"></a>
<span class="sourceLineNo">016</span> * limitations under the License.<a name="line.16"></a>
<span class="sourceLineNo">017</span> */<a name="line.17"></a>
<span class="sourceLineNo">018</span>package org.apache.hadoop.hbase.util;<a name="line.18"></a>
<span class="sourceLineNo">019</span><a name="line.19"></a>
<span class="sourceLineNo">020</span>import java.io.File;<a name="line.20"></a>
<span class="sourceLineNo">021</span>import java.io.IOException;<a name="line.21"></a>
<span class="sourceLineNo">022</span>import java.net.MalformedURLException;<a name="line.22"></a>
<span class="sourceLineNo">023</span>import java.net.URL;<a name="line.23"></a>
<span class="sourceLineNo">024</span>import java.util.HashMap;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import org.apache.hadoop.conf.Configuration;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import org.apache.hadoop.fs.FileStatus;<a name="line.26"></a>
<span class="sourceLineNo">027</span>import org.apache.hadoop.fs.FileSystem;<a name="line.27"></a>
<span class="sourceLineNo">028</span>import org.apache.hadoop.fs.Path;<a name="line.28"></a>
<span class="sourceLineNo">029</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.29"></a>
<span class="sourceLineNo">030</span>import org.slf4j.Logger;<a name="line.30"></a>
<span class="sourceLineNo">031</span>import org.slf4j.LoggerFactory;<a name="line.31"></a>
<span class="sourceLineNo">032</span><a name="line.32"></a>
<span class="sourceLineNo">033</span>/**<a name="line.33"></a>
<span class="sourceLineNo">034</span> * This is a class loader that can load classes dynamically from new jar files under a configured<a name="line.34"></a>
<span class="sourceLineNo">035</span> * folder. The paths to the jar files are converted to URLs, and URLClassLoader logic is actually<a name="line.35"></a>
<span class="sourceLineNo">036</span> * used to load classes. This class loader always uses its parent class loader to load a class at<a name="line.36"></a>
<span class="sourceLineNo">037</span> * first. Only if its parent class loader can not load a class, we will try to load it using the<a name="line.37"></a>
<span class="sourceLineNo">038</span> * logic here.<a name="line.38"></a>
<span class="sourceLineNo">039</span> * &lt;p&gt;<a name="line.39"></a>
<span class="sourceLineNo">040</span> * The configured folder can be a HDFS path. In this case, the jar files under that folder will be<a name="line.40"></a>
<span class="sourceLineNo">041</span> * copied to local at first under ${hbase.local.dir}/jars/. The local copy will be updated if the<a name="line.41"></a>
<span class="sourceLineNo">042</span> * remote copy is updated, according to its last modified timestamp.<a name="line.42"></a>
<span class="sourceLineNo">043</span> * &lt;p&gt;<a name="line.43"></a>
<span class="sourceLineNo">044</span> * We can't unload a class already loaded. So we will use the existing jar files we already know to<a name="line.44"></a>
<span class="sourceLineNo">045</span> * load any class which can't be loaded using the parent class loader. If we still can't load the<a name="line.45"></a>
<span class="sourceLineNo">046</span> * class from the existing jar files, we will check if any new jar file is added, if so, we will<a name="line.46"></a>
<span class="sourceLineNo">047</span> * load the new jar file and try to load the class again. If still failed, a class not found<a name="line.47"></a>
<span class="sourceLineNo">048</span> * exception will be thrown.<a name="line.48"></a>
<span class="sourceLineNo">049</span> * &lt;p&gt;<a name="line.49"></a>
<span class="sourceLineNo">050</span> * Be careful in uploading new jar files and make sure all classes are consistent, otherwise, we may<a name="line.50"></a>
<span class="sourceLineNo">051</span> * not be able to load your classes properly.<a name="line.51"></a>
<span class="sourceLineNo">052</span> */<a name="line.52"></a>
<span class="sourceLineNo">053</span>@InterfaceAudience.Private<a name="line.53"></a>
<span class="sourceLineNo">054</span>public class DynamicClassLoader extends ClassLoaderBase {<a name="line.54"></a>
<span class="sourceLineNo">055</span> private static final Logger LOG = LoggerFactory.getLogger(DynamicClassLoader.class);<a name="line.55"></a>
<span class="sourceLineNo">056</span><a name="line.56"></a>
<span class="sourceLineNo">057</span> // Dynamic jars are put under ${hbase.local.dir}/jars/<a name="line.57"></a>
<span class="sourceLineNo">058</span> private static final String DYNAMIC_JARS_DIR = File.separator + "jars" + File.separator;<a name="line.58"></a>
<span class="sourceLineNo">059</span><a name="line.59"></a>
<span class="sourceLineNo">060</span> private static final String DYNAMIC_JARS_DIR_KEY = "hbase.dynamic.jars.dir";<a name="line.60"></a>
<span class="sourceLineNo">061</span><a name="line.61"></a>
<span class="sourceLineNo">062</span> private static final String DYNAMIC_JARS_OPTIONAL_CONF_KEY = "hbase.use.dynamic.jars";<a name="line.62"></a>
<span class="sourceLineNo">063</span> private static final boolean DYNAMIC_JARS_OPTIONAL_DEFAULT = true;<a name="line.63"></a>
<span class="sourceLineNo">064</span><a name="line.64"></a>
<span class="sourceLineNo">065</span> // The user-provided value for using the DynamicClassLoader<a name="line.65"></a>
<span class="sourceLineNo">066</span> private final boolean userConfigUseDynamicJars;<a name="line.66"></a>
<span class="sourceLineNo">067</span> // The current state of whether to use the DynamicClassLoader<a name="line.67"></a>
<span class="sourceLineNo">068</span> private final boolean useDynamicJars;<a name="line.68"></a>
<span class="sourceLineNo">069</span><a name="line.69"></a>
<span class="sourceLineNo">070</span> private File localDir;<a name="line.70"></a>
<span class="sourceLineNo">071</span><a name="line.71"></a>
<span class="sourceLineNo">072</span> // FileSystem of the remote path, set only if remoteDir != null<a name="line.72"></a>
<span class="sourceLineNo">073</span> private FileSystem remoteDirFs;<a name="line.73"></a>
<span class="sourceLineNo">074</span> private Path remoteDir;<a name="line.74"></a>
<span class="sourceLineNo">075</span><a name="line.75"></a>
<span class="sourceLineNo">076</span> // Last modified time of local jars<a name="line.76"></a>
<span class="sourceLineNo">077</span> private HashMap&lt;String, Long&gt; jarModifiedTime;<a name="line.77"></a>
<span class="sourceLineNo">078</span><a name="line.78"></a>
<span class="sourceLineNo">079</span> /**<a name="line.79"></a>
<span class="sourceLineNo">080</span> * Creates a DynamicClassLoader that can load classes dynamically from jar files under a specific<a name="line.80"></a>
<span class="sourceLineNo">081</span> * folder.<a name="line.81"></a>
<span class="sourceLineNo">082</span> * @param conf the configuration for the cluster.<a name="line.82"></a>
<span class="sourceLineNo">083</span> * @param parent the parent ClassLoader to set.<a name="line.83"></a>
<span class="sourceLineNo">084</span> */<a name="line.84"></a>
<span class="sourceLineNo">085</span> public DynamicClassLoader(final Configuration conf, final ClassLoader parent) {<a name="line.85"></a>
<span class="sourceLineNo">086</span> super(parent);<a name="line.86"></a>
<span class="sourceLineNo">087</span><a name="line.87"></a>
<span class="sourceLineNo">088</span> // Save off the user's original configuration value for the DynamicClassLoader<a name="line.88"></a>
<span class="sourceLineNo">089</span> userConfigUseDynamicJars =<a name="line.89"></a>
<span class="sourceLineNo">090</span> conf.getBoolean(DYNAMIC_JARS_OPTIONAL_CONF_KEY, DYNAMIC_JARS_OPTIONAL_DEFAULT);<a name="line.90"></a>
<span class="sourceLineNo">091</span><a name="line.91"></a>
<span class="sourceLineNo">092</span> boolean dynamicJarsEnabled = userConfigUseDynamicJars;<a name="line.92"></a>
<span class="sourceLineNo">093</span> if (dynamicJarsEnabled) {<a name="line.93"></a>
<span class="sourceLineNo">094</span> try {<a name="line.94"></a>
<span class="sourceLineNo">095</span> initTempDir(conf);<a name="line.95"></a>
<span class="sourceLineNo">096</span> dynamicJarsEnabled = true;<a name="line.96"></a>
<span class="sourceLineNo">097</span> } catch (Exception e) {<a name="line.97"></a>
<span class="sourceLineNo">098</span> LOG.error("Disabling the DynamicClassLoader as it failed to initialize its temp directory."<a name="line.98"></a>
<span class="sourceLineNo">099</span> + " Check your configuration and filesystem permissions. Custom coprocessor code may"<a name="line.99"></a>
<span class="sourceLineNo">100</span> + " not be loaded as a result of this failure.", e);<a name="line.100"></a>
<span class="sourceLineNo">101</span> dynamicJarsEnabled = false;<a name="line.101"></a>
<span class="sourceLineNo">102</span> }<a name="line.102"></a>
<span class="sourceLineNo">103</span> }<a name="line.103"></a>
<span class="sourceLineNo">104</span> useDynamicJars = dynamicJarsEnabled;<a name="line.104"></a>
<span class="sourceLineNo">105</span> }<a name="line.105"></a>
<span class="sourceLineNo">106</span><a name="line.106"></a>
<span class="sourceLineNo">107</span> // FindBugs: Making synchronized to avoid IS2_INCONSISTENT_SYNC complaints about<a name="line.107"></a>
<span class="sourceLineNo">108</span> // remoteDirFs and jarModifiedTime being part synchronized protected.<a name="line.108"></a>
<span class="sourceLineNo">109</span> private synchronized void initTempDir(final Configuration conf) {<a name="line.109"></a>
<span class="sourceLineNo">110</span> jarModifiedTime = new HashMap&lt;&gt;();<a name="line.110"></a>
<span class="sourceLineNo">111</span> String localDirPath = conf.get(LOCAL_DIR_KEY, DEFAULT_LOCAL_DIR) + DYNAMIC_JARS_DIR;<a name="line.111"></a>
<span class="sourceLineNo">112</span> localDir = new File(localDirPath);<a name="line.112"></a>
<span class="sourceLineNo">113</span> if (!localDir.mkdirs() &amp;&amp; !localDir.isDirectory()) {<a name="line.113"></a>
<span class="sourceLineNo">114</span> throw new RuntimeException(<a name="line.114"></a>
<span class="sourceLineNo">115</span> "Failed to create local dir " + localDir.getPath() + ", DynamicClassLoader failed to init");<a name="line.115"></a>
<span class="sourceLineNo">116</span> }<a name="line.116"></a>
<span class="sourceLineNo">117</span><a name="line.117"></a>
<span class="sourceLineNo">118</span> String remotePath = conf.get(DYNAMIC_JARS_DIR_KEY);<a name="line.118"></a>
<span class="sourceLineNo">119</span> if (remotePath == null || remotePath.equals(localDirPath)) {<a name="line.119"></a>
<span class="sourceLineNo">120</span> remoteDir = null; // ignore if it is the same as the local path<a name="line.120"></a>
<span class="sourceLineNo">121</span> } else {<a name="line.121"></a>
<span class="sourceLineNo">122</span> remoteDir = new Path(remotePath);<a name="line.122"></a>
<span class="sourceLineNo">123</span> try {<a name="line.123"></a>
<span class="sourceLineNo">124</span> remoteDirFs = remoteDir.getFileSystem(conf);<a name="line.124"></a>
<span class="sourceLineNo">125</span> } catch (IOException ioe) {<a name="line.125"></a>
<span class="sourceLineNo">126</span> LOG.warn("Failed to identify the fs of dir " + remoteDir + ", ignored", ioe);<a name="line.126"></a>
<span class="sourceLineNo">127</span> remoteDir = null;<a name="line.127"></a>
<span class="sourceLineNo">128</span> }<a name="line.128"></a>
<span class="sourceLineNo">129</span> }<a name="line.129"></a>
<span class="sourceLineNo">130</span> }<a name="line.130"></a>
<span class="sourceLineNo">131</span><a name="line.131"></a>
<span class="sourceLineNo">132</span> @Override<a name="line.132"></a>
<span class="sourceLineNo">133</span> public Class&lt;?&gt; loadClass(String name) throws ClassNotFoundException {<a name="line.133"></a>
<span class="sourceLineNo">134</span> try {<a name="line.134"></a>
<span class="sourceLineNo">135</span> return parent.loadClass(name);<a name="line.135"></a>
<span class="sourceLineNo">136</span> } catch (ClassNotFoundException e) {<a name="line.136"></a>
<span class="sourceLineNo">137</span> if (useDynamicJars) {<a name="line.137"></a>
<span class="sourceLineNo">138</span> LOG.debug("Class {} not found - using dynamical class loader", name);<a name="line.138"></a>
<span class="sourceLineNo">139</span> return tryRefreshClass(name);<a name="line.139"></a>
<span class="sourceLineNo">140</span> } else if (userConfigUseDynamicJars) {<a name="line.140"></a>
<span class="sourceLineNo">141</span> // If the user tried to enable the DCL, then warn again.<a name="line.141"></a>
<span class="sourceLineNo">142</span> LOG.debug("Not checking DynamicClassLoader for missing class because it is disabled."<a name="line.142"></a>
<span class="sourceLineNo">143</span> + " See the log for previous errors.");<a name="line.143"></a>
<span class="sourceLineNo">144</span> }<a name="line.144"></a>
<span class="sourceLineNo">145</span> throw e;<a name="line.145"></a>
<span class="sourceLineNo">146</span> }<a name="line.146"></a>
<span class="sourceLineNo">147</span> }<a name="line.147"></a>
<span class="sourceLineNo">148</span><a name="line.148"></a>
<span class="sourceLineNo">149</span> private Class&lt;?&gt; tryRefreshClass(String name) throws ClassNotFoundException {<a name="line.149"></a>
<span class="sourceLineNo">150</span> synchronized (getClassLoadingLock(name)) {<a name="line.150"></a>
<span class="sourceLineNo">151</span> // Check whether the class has already been loaded:<a name="line.151"></a>
<span class="sourceLineNo">152</span> Class&lt;?&gt; clasz = findLoadedClass(name);<a name="line.152"></a>
<span class="sourceLineNo">153</span><a name="line.153"></a>
<span class="sourceLineNo">154</span> if (clasz != null) {<a name="line.154"></a>
<span class="sourceLineNo">155</span> if (LOG.isDebugEnabled()) {<a name="line.155"></a>
<span class="sourceLineNo">156</span> LOG.debug("Class {} already loaded", name);<a name="line.156"></a>
<span class="sourceLineNo">157</span> }<a name="line.157"></a>
<span class="sourceLineNo">158</span> } else {<a name="line.158"></a>
<span class="sourceLineNo">159</span> try {<a name="line.159"></a>
<span class="sourceLineNo">160</span> if (LOG.isDebugEnabled()) {<a name="line.160"></a>
<span class="sourceLineNo">161</span> LOG.debug("Finding class: {}", name);<a name="line.161"></a>
<span class="sourceLineNo">162</span> }<a name="line.162"></a>
<span class="sourceLineNo">163</span><a name="line.163"></a>
<span class="sourceLineNo">164</span> clasz = findClass(name);<a name="line.164"></a>
<span class="sourceLineNo">165</span> } catch (ClassNotFoundException cnfe) {<a name="line.165"></a>
<span class="sourceLineNo">166</span> // Load new jar files if any<a name="line.166"></a>
<span class="sourceLineNo">167</span> if (LOG.isDebugEnabled()) {<a name="line.167"></a>
<span class="sourceLineNo">168</span> LOG.debug("Loading new jar files, if any");<a name="line.168"></a>
<span class="sourceLineNo">169</span> }<a name="line.169"></a>
<span class="sourceLineNo">170</span><a name="line.170"></a>
<span class="sourceLineNo">171</span> loadNewJars();<a name="line.171"></a>
<span class="sourceLineNo">172</span><a name="line.172"></a>
<span class="sourceLineNo">173</span> if (LOG.isDebugEnabled()) {<a name="line.173"></a>
<span class="sourceLineNo">174</span> LOG.debug("Finding class again: {}", name);<a name="line.174"></a>
<span class="sourceLineNo">175</span> }<a name="line.175"></a>
<span class="sourceLineNo">176</span><a name="line.176"></a>
<span class="sourceLineNo">177</span> clasz = findClass(name);<a name="line.177"></a>
<span class="sourceLineNo">178</span> }<a name="line.178"></a>
<span class="sourceLineNo">179</span> }<a name="line.179"></a>
<span class="sourceLineNo">180</span><a name="line.180"></a>
<span class="sourceLineNo">181</span> return clasz;<a name="line.181"></a>
<span class="sourceLineNo">182</span> }<a name="line.182"></a>
<span class="sourceLineNo">183</span> }<a name="line.183"></a>
<span class="sourceLineNo">184</span><a name="line.184"></a>
<span class="sourceLineNo">185</span> private synchronized void loadNewJars() {<a name="line.185"></a>
<span class="sourceLineNo">186</span> // Refresh local jar file lists<a name="line.186"></a>
<span class="sourceLineNo">187</span> File[] files = localDir == null ? null : localDir.listFiles();<a name="line.187"></a>
<span class="sourceLineNo">188</span> if (files != null) {<a name="line.188"></a>
<span class="sourceLineNo">189</span> for (File file : files) {<a name="line.189"></a>
<span class="sourceLineNo">190</span> String fileName = file.getName();<a name="line.190"></a>
<span class="sourceLineNo">191</span> if (jarModifiedTime.containsKey(fileName)) {<a name="line.191"></a>
<span class="sourceLineNo">192</span> continue;<a name="line.192"></a>
<span class="sourceLineNo">193</span> }<a name="line.193"></a>
<span class="sourceLineNo">194</span> if (file.isFile() &amp;&amp; fileName.endsWith(".jar")) {<a name="line.194"></a>
<span class="sourceLineNo">195</span> jarModifiedTime.put(fileName, file.lastModified());<a name="line.195"></a>
<span class="sourceLineNo">196</span> try {<a name="line.196"></a>
<span class="sourceLineNo">197</span> URL url = file.toURI().toURL();<a name="line.197"></a>
<span class="sourceLineNo">198</span> addURL(url);<a name="line.198"></a>
<span class="sourceLineNo">199</span> } catch (MalformedURLException mue) {<a name="line.199"></a>
<span class="sourceLineNo">200</span> // This should not happen, just log it<a name="line.200"></a>
<span class="sourceLineNo">201</span> LOG.warn("Failed to load new jar " + fileName, mue);<a name="line.201"></a>
<span class="sourceLineNo">202</span> }<a name="line.202"></a>
<span class="sourceLineNo">203</span> }<a name="line.203"></a>
<span class="sourceLineNo">204</span> }<a name="line.204"></a>
<span class="sourceLineNo">205</span> }<a name="line.205"></a>
<span class="sourceLineNo">206</span><a name="line.206"></a>
<span class="sourceLineNo">207</span> // Check remote files<a name="line.207"></a>
<span class="sourceLineNo">208</span> FileStatus[] statuses = null;<a name="line.208"></a>
<span class="sourceLineNo">209</span> if (remoteDir != null) {<a name="line.209"></a>
<span class="sourceLineNo">210</span> try {<a name="line.210"></a>
<span class="sourceLineNo">211</span> statuses = remoteDirFs.listStatus(remoteDir);<a name="line.211"></a>
<span class="sourceLineNo">212</span> } catch (IOException ioe) {<a name="line.212"></a>
<span class="sourceLineNo">213</span> LOG.warn("Failed to check remote dir status " + remoteDir, ioe);<a name="line.213"></a>
<span class="sourceLineNo">214</span> }<a name="line.214"></a>
<span class="sourceLineNo">215</span> }<a name="line.215"></a>
<span class="sourceLineNo">216</span> if (statuses == null || statuses.length == 0) {<a name="line.216"></a>
<span class="sourceLineNo">217</span> return; // no remote files at all<a name="line.217"></a>
<span class="sourceLineNo">218</span> }<a name="line.218"></a>
<span class="sourceLineNo">219</span><a name="line.219"></a>
<span class="sourceLineNo">220</span> for (FileStatus status : statuses) {<a name="line.220"></a>
<span class="sourceLineNo">221</span> if (status.isDirectory()) {<a name="line.221"></a>
<span class="sourceLineNo">222</span> continue; // No recursive lookup<a name="line.222"></a>
<span class="sourceLineNo">223</span> }<a name="line.223"></a>
<span class="sourceLineNo">224</span><a name="line.224"></a>
<span class="sourceLineNo">225</span> Path path = status.getPath();<a name="line.225"></a>
<span class="sourceLineNo">226</span> String fileName = path.getName();<a name="line.226"></a>
<span class="sourceLineNo">227</span> if (!fileName.endsWith(".jar")) {<a name="line.227"></a>
<span class="sourceLineNo">228</span> if (LOG.isDebugEnabled()) {<a name="line.228"></a>
<span class="sourceLineNo">229</span> LOG.debug("Ignored non-jar file {}", fileName);<a name="line.229"></a>
<span class="sourceLineNo">230</span> }<a name="line.230"></a>
<span class="sourceLineNo">231</span> continue; // Ignore non-jar files<a name="line.231"></a>
<span class="sourceLineNo">232</span> }<a name="line.232"></a>
<span class="sourceLineNo">233</span> Long cachedLastModificationTime = jarModifiedTime.get(fileName);<a name="line.233"></a>
<span class="sourceLineNo">234</span> if (cachedLastModificationTime != null) {<a name="line.234"></a>
<span class="sourceLineNo">235</span> long lastModified = status.getModificationTime();<a name="line.235"></a>
<span class="sourceLineNo">236</span> if (lastModified &lt; cachedLastModificationTime) {<a name="line.236"></a>
<span class="sourceLineNo">237</span> // There could be some race, for example, someone uploads<a name="line.237"></a>
<span class="sourceLineNo">238</span> // a new one right in the middle the old one is copied to<a name="line.238"></a>
<span class="sourceLineNo">239</span> // local. We can check the size as well. But it is still<a name="line.239"></a>
<span class="sourceLineNo">240</span> // not guaranteed. This should be rare. Most likely,<a name="line.240"></a>
<span class="sourceLineNo">241</span> // we already have the latest one.<a name="line.241"></a>
<span class="sourceLineNo">242</span> // If you are unlucky to hit this race issue, you have<a name="line.242"></a>
<span class="sourceLineNo">243</span> // to touch the remote jar to update its last modified time<a name="line.243"></a>
<span class="sourceLineNo">244</span> continue;<a name="line.244"></a>
<span class="sourceLineNo">245</span> }<a name="line.245"></a>
<span class="sourceLineNo">246</span> }<a name="line.246"></a>
<span class="sourceLineNo">247</span> try {<a name="line.247"></a>
<span class="sourceLineNo">248</span> // Copy it to local<a name="line.248"></a>
<span class="sourceLineNo">249</span> File dst = new File(localDir, fileName);<a name="line.249"></a>
<span class="sourceLineNo">250</span> remoteDirFs.copyToLocalFile(path, new Path(dst.getPath()));<a name="line.250"></a>
<span class="sourceLineNo">251</span> jarModifiedTime.put(fileName, dst.lastModified());<a name="line.251"></a>
<span class="sourceLineNo">252</span> URL url = dst.toURI().toURL();<a name="line.252"></a>
<span class="sourceLineNo">253</span> addURL(url);<a name="line.253"></a>
<span class="sourceLineNo">254</span> } catch (IOException ioe) {<a name="line.254"></a>
<span class="sourceLineNo">255</span> LOG.warn("Failed to load new jar " + fileName, ioe);<a name="line.255"></a>
<span class="sourceLineNo">256</span> }<a name="line.256"></a>
<span class="sourceLineNo">257</span> }<a name="line.257"></a>
<span class="sourceLineNo">258</span> }<a name="line.258"></a>
<span class="sourceLineNo">259</span>}<a name="line.259"></a>
</pre>
</div>
</body>
</html>