title: I am getting trouble when I use command java -jni HelloWorld
body: <p>I am learning how to use jni(java native interface), and I follows steps presented by a blog. I have created a java file named 'HelloWorld.java',content as following:</p>
  
  <pre><code>public class HelloWorld { 
      public native void displayHelloWorld(); 
      static { 
          System.loadLibrary("HelloWorldImpl"); 
      } 
      public static void main(String[] args) 
      { 
      // TODO Auto-generated method stub 
          HelloWorld helloWorld = new HelloWorld(); 
          helloWorld.displayHelloWorld(); 
      } 
  }
  </code></pre>
  
  <p>then I execute this command:</p>
  
  <pre><code>javac HelloWorld
  </code></pre>
  
  <p>there's no error happened,  but when I execute this command:</p>
  
  <pre><code>javah -jni HelloWorld
  </code></pre>
  
  <p>then I get a error:</p>
  
  <pre><code>can't find class "HelloWorld"
  </code></pre>
  
  <p>I am sure, this directory has the HelloWorld.class file that have been compile.</p>
  
  <p>the dev:</p>
  
  <pre><code>jdk8
  windows 10 64bits
  </code></pre>
  
  <p>I have google for a long time and asked my classmates who are successful using  same steps, but cannot deal with this problem, something was wrong in my laptop?
  anyone could help me?Thank a lot.</p>