title: Why can't I load my class by ExtClassLoader?
body: <p>This is the structure of my Java project:</p>
  
  <pre><code>package: com.study.test
                ---- HelloWorld.java
                ---- Test.java
  </code></pre>
  
  <p>The content of <strong>HelloWorld.java</strong>:</p>
  
  <pre><code>package com.study.test;
  
  public class HelloWorld {}
  </code></pre>
  
  <p>The content of <strong>Test.java</strong>:</p>
  
  <pre><code>package com.study.test;
  
  public class Test {
  
      public static void main(String[] args) {
          System.out.println(System.getProperty("java.ext.dirs"));
          System.out.println(HelloWorld.class.getClassLoader());
      }
  
  }
  </code></pre>
  
  <p>The value of the "<strong>java.ext.dirs</strong>" is:</p>
  
  <pre><code>D:\glassfish4\jdk7\jre\lib\ext;C:\windows\Sun\Java\lib\ext
  </code></pre>
  
  <p>I put the class file <strong>HelloWorld.class</strong> in directory:</p>
  
  <pre><code>D:\glassfish4\jdk7\jre\lib\ext\com\study\test
  </code></pre>
  
  <p>but the output of "<code>System.out.println(HelloWorld.class.getClassLoader());</code>" is:</p>
  
  <pre><code>sun.misc.Launcher$AppClassLoader@70a0afab
  </code></pre>
  
  <p>Why the class HelloWorld isn't loaded by ExtClassLoader? ExtClassLoader is the parent class loader of AppClassLoader.</p>