title: How to resolve this error Caused by: java.lang.ClassNotFoundException
body: <p>I wrote a console application <code>helloworld.java</code> and ran <code>javac helloworld.java</code>,and then <code>java helloworld</code>. This worked fine.</p>
  
  <p>I then created a package <code>com.abc.project</code> and moved helloworld.java into it(the package import statement is correctly generated which is <code>package com.abc.project;</code>). And then i ran <code>javac helloworld.java</code> this worked also fine and generated the class properly.</p>
  
  <p>However, when I ran <code>java com.abc.project.helloworld</code> from the console, it threw an "class not found" error.</p>
  
  <p>Please can anyone advise what is the problem? </p>