java.lang.NoClassDefFoundError error in android
<p>I try to import a .jar lib.
Add in code, I import it with no error.</p>

<pre><code>import my.lib.MyLib;
</code></pre>

<p>And I use the class MyLib which in the lib in onCreate().
But it show below error:</p>

<pre><code>java.lang.NoClassDefFoundError: my.lib.MyLib
</code></pre>

<p>What is the possible reason? 
And how to modify it?</p>
