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  9. <div id="overview"><a href="../../../../../apidocs/org/apache/log4j/helpers/Loader.html">View Javadoc</a></div><pre>
  10. <a name="1" href="#1">1</a> <em class="jxr_comment">/*</em>
  11. <a name="2" href="#2">2</a> <em class="jxr_comment"> * Licensed to the Apache Software Foundation (ASF) under one or more</em>
  12. <a name="3" href="#3">3</a> <em class="jxr_comment"> * contributor license agreements. See the NOTICE file distributed with</em>
  13. <a name="4" href="#4">4</a> <em class="jxr_comment"> * this work for additional information regarding copyright ownership.</em>
  14. <a name="5" href="#5">5</a> <em class="jxr_comment"> * The ASF licenses this file to You under the Apache License, Version 2.0</em>
  15. <a name="6" href="#6">6</a> <em class="jxr_comment"> * (the "License"); you may not use this file except in compliance with</em>
  16. <a name="7" href="#7">7</a> <em class="jxr_comment"> * the License. You may obtain a copy of the License at</em>
  17. <a name="8" href="#8">8</a> <em class="jxr_comment"> * </em>
  18. <a name="9" href="#9">9</a> <em class="jxr_comment"> * <a href="http://www.apache.org/licenses/LICENSE-2.0" target="alexandria_uri">http://www.apache.org/licenses/LICENSE-2.0</a></em>
  19. <a name="10" href="#10">10</a> <em class="jxr_comment"> * </em>
  20. <a name="11" href="#11">11</a> <em class="jxr_comment"> * Unless required by applicable law or agreed to in writing, software</em>
  21. <a name="12" href="#12">12</a> <em class="jxr_comment"> * distributed under the License is distributed on an "AS IS" BASIS,</em>
  22. <a name="13" href="#13">13</a> <em class="jxr_comment"> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</em>
  23. <a name="14" href="#14">14</a> <em class="jxr_comment"> * See the License for the specific language governing permissions and</em>
  24. <a name="15" href="#15">15</a> <em class="jxr_comment"> * limitations under the License.</em>
  25. <a name="16" href="#16">16</a> <em class="jxr_comment"> */</em>
  26. <a name="17" href="#17">17</a>
  27. <a name="18" href="#18">18</a> <strong class="jxr_keyword">package</strong> org.apache.log4j.helpers;
  28. <a name="19" href="#19">19</a>
  29. <a name="20" href="#20">20</a> <strong class="jxr_keyword">import</strong> java.net.URL;
  30. <a name="21" href="#21">21</a> <strong class="jxr_keyword">import</strong> java.lang.reflect.Method;
  31. <a name="22" href="#22">22</a> <strong class="jxr_keyword">import</strong> java.lang.reflect.InvocationTargetException;
  32. <a name="23" href="#23">23</a> <strong class="jxr_keyword">import</strong> java.io.InterruptedIOException;
  33. <a name="24" href="#24">24</a>
  34. <a name="25" href="#25">25</a>
  35. <a name="26" href="#26">26</a> <em class="jxr_javadoccomment">/**</em>
  36. <a name="27" href="#27">27</a> <em class="jxr_javadoccomment"> Load resources (or images) from various sources.</em>
  37. <a name="28" href="#28">28</a> <em class="jxr_javadoccomment"> </em>
  38. <a name="29" href="#29">29</a> <em class="jxr_javadoccomment"> @author Ceki G&amp;uuml;lc&amp;uuml;</em>
  39. <a name="30" href="#30">30</a> <em class="jxr_javadoccomment"> */</em>
  40. <a name="31" href="#31">31</a>
  41. <a name="32" href="#32">32</a> <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">class</strong> <a href="../../../../org/apache/log4j/helpers/Loader.html">Loader</a> {
  42. <a name="33" href="#33">33</a>
  43. <a name="34" href="#34">34</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">final</strong> String TSTR = <span class="jxr_string">"Caught Exception while in Loader.getResource. This may be innocuous."</span>;
  44. <a name="35" href="#35">35</a>
  45. <a name="36" href="#36">36</a> <em class="jxr_comment">// We conservatively assume that we are running under Java 1.x</em>
  46. <a name="37" href="#37">37</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">private</strong> <strong class="jxr_keyword">boolean</strong> java1 = <strong class="jxr_keyword">true</strong>;
  47. <a name="38" href="#38">38</a>
  48. <a name="39" href="#39">39</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">private</strong> <strong class="jxr_keyword">boolean</strong> ignoreTCL = false;
  49. <a name="40" href="#40">40</a>
  50. <a name="41" href="#41">41</a> <strong class="jxr_keyword">static</strong> {
  51. <a name="42" href="#42">42</a> String prop = OptionConverter.getSystemProperty(<span class="jxr_string">"java.version"</span>, <strong class="jxr_keyword">null</strong>);
  52. <a name="43" href="#43">43</a>
  53. <a name="44" href="#44">44</a> <strong class="jxr_keyword">if</strong>(prop != <strong class="jxr_keyword">null</strong>) {
  54. <a name="45" href="#45">45</a> <strong class="jxr_keyword">int</strong> i = prop.indexOf('.');
  55. <a name="46" href="#46">46</a> <strong class="jxr_keyword">if</strong>(i != -1) {
  56. <a name="47" href="#47">47</a> <strong class="jxr_keyword">if</strong>(prop.charAt(i+1) != '1')
  57. <a name="48" href="#48">48</a> java1 = false;
  58. <a name="49" href="#49">49</a> }
  59. <a name="50" href="#50">50</a> }
  60. <a name="51" href="#51">51</a> String ignoreTCLProp = OptionConverter.getSystemProperty(<span class="jxr_string">"log4j.ignoreTCL"</span>, <strong class="jxr_keyword">null</strong>);
  61. <a name="52" href="#52">52</a> <strong class="jxr_keyword">if</strong>(ignoreTCLProp != <strong class="jxr_keyword">null</strong>) {
  62. <a name="53" href="#53">53</a> ignoreTCL = OptionConverter.toBoolean(ignoreTCLProp, <strong class="jxr_keyword">true</strong>);
  63. <a name="54" href="#54">54</a> }
  64. <a name="55" href="#55">55</a> }
  65. <a name="56" href="#56">56</a>
  66. <a name="57" href="#57">57</a> <em class="jxr_javadoccomment">/**</em>
  67. <a name="58" href="#58">58</a> <em class="jxr_javadoccomment"> * Get a resource by delegating to getResource(String).</em>
  68. <a name="59" href="#59">59</a> <em class="jxr_javadoccomment"> * @param resource resource name</em>
  69. <a name="60" href="#60">60</a> <em class="jxr_javadoccomment"> * @param clazz class, ignored.</em>
  70. <a name="61" href="#61">61</a> <em class="jxr_javadoccomment"> * @return URL to resource or null.</em>
  71. <a name="62" href="#62">62</a> <em class="jxr_javadoccomment"> * @deprecated as of 1.2.</em>
  72. <a name="63" href="#63">63</a> <em class="jxr_javadoccomment"> */</em>
  73. <a name="64" href="#64">64</a> <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> URL getResource(String resource, Class clazz) {
  74. <a name="65" href="#65">65</a> <strong class="jxr_keyword">return</strong> getResource(resource);
  75. <a name="66" href="#66">66</a> }
  76. <a name="67" href="#67">67</a>
  77. <a name="68" href="#68">68</a> <em class="jxr_javadoccomment">/**</em>
  78. <a name="69" href="#69">69</a> <em class="jxr_javadoccomment"> This method will search for &lt;code&gt;resource&lt;/code&gt; in different</em>
  79. <a name="70" href="#70">70</a> <em class="jxr_javadoccomment"> places. The search order is as follows:</em>
  80. <a name="71" href="#71">71</a>
  81. <a name="72" href="#72">72</a> <em class="jxr_javadoccomment"> &lt;ol&gt;</em>
  82. <a name="73" href="#73">73</a>
  83. <a name="74" href="#74">74</a> <em class="jxr_javadoccomment"> &lt;p&gt;&lt;li&gt;Search for &lt;code&gt;resource&lt;/code&gt; using the thread context</em>
  84. <a name="75" href="#75">75</a> <em class="jxr_javadoccomment"> class loader under Java2. If that fails, search for</em>
  85. <a name="76" href="#76">76</a> <em class="jxr_javadoccomment"> &lt;code&gt;resource&lt;/code&gt; using the class loader that loaded this</em>
  86. <a name="77" href="#77">77</a> <em class="jxr_javadoccomment"> class (&lt;code&gt;Loader&lt;/code&gt;). Under JDK 1.1, only the the class</em>
  87. <a name="78" href="#78">78</a> <em class="jxr_javadoccomment"> loader that loaded this class (&lt;code&gt;Loader&lt;/code&gt;) is used.</em>
  88. <a name="79" href="#79">79</a>
  89. <a name="80" href="#80">80</a> <em class="jxr_javadoccomment"> &lt;p&gt;&lt;li&gt;Try one last time with</em>
  90. <a name="81" href="#81">81</a> <em class="jxr_javadoccomment"> &lt;code&gt;ClassLoader.getSystemResource(resource)&lt;/code&gt;, that is is</em>
  91. <a name="82" href="#82">82</a> <em class="jxr_javadoccomment"> using the system class loader in JDK 1.2 and virtual machine's</em>
  92. <a name="83" href="#83">83</a> <em class="jxr_javadoccomment"> built-in class loader in JDK 1.1.</em>
  93. <a name="84" href="#84">84</a>
  94. <a name="85" href="#85">85</a> <em class="jxr_javadoccomment"> &lt;/ol&gt;</em>
  95. <a name="86" href="#86">86</a> <em class="jxr_javadoccomment"> */</em>
  96. <a name="87" href="#87">87</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">public</strong> URL getResource(String resource) {
  97. <a name="88" href="#88">88</a> ClassLoader classLoader = <strong class="jxr_keyword">null</strong>;
  98. <a name="89" href="#89">89</a> URL url = <strong class="jxr_keyword">null</strong>;
  99. <a name="90" href="#90">90</a>
  100. <a name="91" href="#91">91</a> <strong class="jxr_keyword">try</strong> {
  101. <a name="92" href="#92">92</a> <strong class="jxr_keyword">if</strong>(!java1 &amp;&amp; !ignoreTCL) {
  102. <a name="93" href="#93">93</a> classLoader = getTCL();
  103. <a name="94" href="#94">94</a> <strong class="jxr_keyword">if</strong>(classLoader != <strong class="jxr_keyword">null</strong>) {
  104. <a name="95" href="#95">95</a> LogLog.debug(<span class="jxr_string">"Trying to find ["</span>+resource+<span class="jxr_string">"] using context classloader "</span>
  105. <a name="96" href="#96">96</a> +classLoader+<span class="jxr_string">"."</span>);
  106. <a name="97" href="#97">97</a> url = classLoader.getResource(resource);
  107. <a name="98" href="#98">98</a> <strong class="jxr_keyword">if</strong>(url != <strong class="jxr_keyword">null</strong>) {
  108. <a name="99" href="#99">99</a> <strong class="jxr_keyword">return</strong> url;
  109. <a name="100" href="#100">100</a> }
  110. <a name="101" href="#101">101</a> }
  111. <a name="102" href="#102">102</a> }
  112. <a name="103" href="#103">103</a>
  113. <a name="104" href="#104">104</a> <em class="jxr_comment">// We could not find resource. Ler us now try with the</em>
  114. <a name="105" href="#105">105</a> <em class="jxr_comment">// classloader that loaded this class.</em>
  115. <a name="106" href="#106">106</a> classLoader = Loader.<strong class="jxr_keyword">class</strong>.getClassLoader();
  116. <a name="107" href="#107">107</a> <strong class="jxr_keyword">if</strong>(classLoader != <strong class="jxr_keyword">null</strong>) {
  117. <a name="108" href="#108">108</a> LogLog.debug(<span class="jxr_string">"Trying to find ["</span>+resource+<span class="jxr_string">"] using "</span>+classLoader
  118. <a name="109" href="#109">109</a> +<span class="jxr_string">" class loader."</span>);
  119. <a name="110" href="#110">110</a> url = classLoader.getResource(resource);
  120. <a name="111" href="#111">111</a> <strong class="jxr_keyword">if</strong>(url != <strong class="jxr_keyword">null</strong>) {
  121. <a name="112" href="#112">112</a> <strong class="jxr_keyword">return</strong> url;
  122. <a name="113" href="#113">113</a> }
  123. <a name="114" href="#114">114</a> }
  124. <a name="115" href="#115">115</a> } <strong class="jxr_keyword">catch</strong>(IllegalAccessException t) {
  125. <a name="116" href="#116">116</a> LogLog.warn(TSTR, t);
  126. <a name="117" href="#117">117</a> } <strong class="jxr_keyword">catch</strong>(InvocationTargetException t) {
  127. <a name="118" href="#118">118</a> <strong class="jxr_keyword">if</strong> (t.getTargetException() instanceof InterruptedException
  128. <a name="119" href="#119">119</a> || t.getTargetException() instanceof InterruptedIOException) {
  129. <a name="120" href="#120">120</a> Thread.currentThread().interrupt();
  130. <a name="121" href="#121">121</a> }
  131. <a name="122" href="#122">122</a> LogLog.warn(TSTR, t);
  132. <a name="123" href="#123">123</a> } <strong class="jxr_keyword">catch</strong>(Throwable t) {
  133. <a name="124" href="#124">124</a> <em class="jxr_comment">//</em>
  134. <a name="125" href="#125">125</a> <em class="jxr_comment">// can't be InterruptedException or InterruptedIOException</em>
  135. <a name="126" href="#126">126</a> <em class="jxr_comment">// since not declared, must be error or RuntimeError.</em>
  136. <a name="127" href="#127">127</a> LogLog.warn(TSTR, t);
  137. <a name="128" href="#128">128</a> }
  138. <a name="129" href="#129">129</a>
  139. <a name="130" href="#130">130</a> <em class="jxr_comment">// Last ditch attempt: get the resource from the class path. It</em>
  140. <a name="131" href="#131">131</a> <em class="jxr_comment">// may be the case that clazz was loaded by the Extentsion class</em>
  141. <a name="132" href="#132">132</a> <em class="jxr_comment">// loader which the parent of the system class loader. Hence the</em>
  142. <a name="133" href="#133">133</a> <em class="jxr_comment">// code below.</em>
  143. <a name="134" href="#134">134</a> LogLog.debug(<span class="jxr_string">"Trying to find ["</span>+resource+
  144. <a name="135" href="#135">135</a> <span class="jxr_string">"] using ClassLoader.getSystemResource()."</span>);
  145. <a name="136" href="#136">136</a> <strong class="jxr_keyword">return</strong> ClassLoader.getSystemResource(resource);
  146. <a name="137" href="#137">137</a> }
  147. <a name="138" href="#138">138</a>
  148. <a name="139" href="#139">139</a> <em class="jxr_javadoccomment">/**</em>
  149. <a name="140" href="#140">140</a> <em class="jxr_javadoccomment"> Are we running under JDK 1.x? </em>
  150. <a name="141" href="#141">141</a> <em class="jxr_javadoccomment"> */</em>
  151. <a name="142" href="#142">142</a> <strong class="jxr_keyword">public</strong>
  152. <a name="143" href="#143">143</a> <strong class="jxr_keyword">static</strong>
  153. <a name="144" href="#144">144</a> <strong class="jxr_keyword">boolean</strong> isJava1() {
  154. <a name="145" href="#145">145</a> <strong class="jxr_keyword">return</strong> java1;
  155. <a name="146" href="#146">146</a> }
  156. <a name="147" href="#147">147</a>
  157. <a name="148" href="#148">148</a> <em class="jxr_javadoccomment">/**</em>
  158. <a name="149" href="#149">149</a> <em class="jxr_javadoccomment"> * Get the Thread Context Loader which is a JDK 1.2 feature. If we</em>
  159. <a name="150" href="#150">150</a> <em class="jxr_javadoccomment"> * are running under JDK 1.1 or anything else goes wrong the method</em>
  160. <a name="151" href="#151">151</a> <em class="jxr_javadoccomment"> * returns &lt;code&gt;null&lt;code&gt;.</em>
  161. <a name="152" href="#152">152</a> <em class="jxr_javadoccomment"> *</em>
  162. <a name="153" href="#153">153</a> <em class="jxr_javadoccomment"> * */</em>
  163. <a name="154" href="#154">154</a> <strong class="jxr_keyword">private</strong> <strong class="jxr_keyword">static</strong> ClassLoader getTCL() <strong class="jxr_keyword">throws</strong> IllegalAccessException,
  164. <a name="155" href="#155">155</a> InvocationTargetException {
  165. <a name="156" href="#156">156</a>
  166. <a name="157" href="#157">157</a> <em class="jxr_comment">// Are we running on a JDK 1.2 or later system?</em>
  167. <a name="158" href="#158">158</a> Method method = <strong class="jxr_keyword">null</strong>;
  168. <a name="159" href="#159">159</a> <strong class="jxr_keyword">try</strong> {
  169. <a name="160" href="#160">160</a> method = Thread.<strong class="jxr_keyword">class</strong>.getMethod(<span class="jxr_string">"getContextClassLoader"</span>, <strong class="jxr_keyword">null</strong>);
  170. <a name="161" href="#161">161</a> } <strong class="jxr_keyword">catch</strong> (NoSuchMethodException e) {
  171. <a name="162" href="#162">162</a> <em class="jxr_comment">// We are running on JDK 1.1</em>
  172. <a name="163" href="#163">163</a> <strong class="jxr_keyword">return</strong> <strong class="jxr_keyword">null</strong>;
  173. <a name="164" href="#164">164</a> }
  174. <a name="165" href="#165">165</a>
  175. <a name="166" href="#166">166</a> <strong class="jxr_keyword">return</strong> (ClassLoader) method.invoke(Thread.currentThread(), <strong class="jxr_keyword">null</strong>);
  176. <a name="167" href="#167">167</a> }
  177. <a name="168" href="#168">168</a>
  178. <a name="169" href="#169">169</a>
  179. <a name="170" href="#170">170</a>
  180. <a name="171" href="#171">171</a> <em class="jxr_javadoccomment">/**</em>
  181. <a name="172" href="#172">172</a> <em class="jxr_javadoccomment"> * If running under JDK 1.2 load the specified class using the</em>
  182. <a name="173" href="#173">173</a> <em class="jxr_javadoccomment"> * &lt;code&gt;Thread&lt;/code&gt; &lt;code&gt;contextClassLoader&lt;/code&gt; if that</em>
  183. <a name="174" href="#174">174</a> <em class="jxr_javadoccomment"> * fails try Class.forname. Under JDK 1.1 only Class.forName is</em>
  184. <a name="175" href="#175">175</a> <em class="jxr_javadoccomment"> * used.</em>
  185. <a name="176" href="#176">176</a> <em class="jxr_javadoccomment"> *</em>
  186. <a name="177" href="#177">177</a> <em class="jxr_javadoccomment"> */</em>
  187. <a name="178" href="#178">178</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">public</strong> Class loadClass (String clazz) <strong class="jxr_keyword">throws</strong> ClassNotFoundException {
  188. <a name="179" href="#179">179</a> <em class="jxr_comment">// Just call Class.forName(clazz) if we are running under JDK 1.1</em>
  189. <a name="180" href="#180">180</a> <em class="jxr_comment">// or if we are instructed to ignore the TCL.</em>
  190. <a name="181" href="#181">181</a> <strong class="jxr_keyword">if</strong>(java1 || ignoreTCL) {
  191. <a name="182" href="#182">182</a> <strong class="jxr_keyword">return</strong> Class.forName(clazz);
  192. <a name="183" href="#183">183</a> } <strong class="jxr_keyword">else</strong> {
  193. <a name="184" href="#184">184</a> <strong class="jxr_keyword">try</strong> {
  194. <a name="185" href="#185">185</a> <strong class="jxr_keyword">return</strong> getTCL().loadClass(clazz);
  195. <a name="186" href="#186">186</a> }
  196. <a name="187" href="#187">187</a> <em class="jxr_comment">// we reached here because tcl was null or because of a</em>
  197. <a name="188" href="#188">188</a> <em class="jxr_comment">// security exception, or because clazz could not be loaded...</em>
  198. <a name="189" href="#189">189</a> <em class="jxr_comment">// In any case we now try one more time</em>
  199. <a name="190" href="#190">190</a> <strong class="jxr_keyword">catch</strong>(InvocationTargetException e) {
  200. <a name="191" href="#191">191</a> <strong class="jxr_keyword">if</strong> (e.getTargetException() instanceof InterruptedException
  201. <a name="192" href="#192">192</a> || e.getTargetException() instanceof InterruptedIOException) {
  202. <a name="193" href="#193">193</a> Thread.currentThread().interrupt();
  203. <a name="194" href="#194">194</a> }
  204. <a name="195" href="#195">195</a> } <strong class="jxr_keyword">catch</strong>(Throwable t) {
  205. <a name="196" href="#196">196</a> }
  206. <a name="197" href="#197">197</a> }
  207. <a name="198" href="#198">198</a> <strong class="jxr_keyword">return</strong> Class.forName(clazz);
  208. <a name="199" href="#199">199</a> }
  209. <a name="200" href="#200">200</a> }
  210. </pre>
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