<p>According to the Java Language Specification:</p>

<blockquote>
Unnamed packages are provided by the Java platform principally for convenience when developing small or temporary applications or when just beginning development.
</blockquote>

<p>To enforce this best practice, classes located in default package can no longer be access from named ones since Java 1.4.</p>

<p>The following piece of code:</p>

<pre>
public class MyClass { /* ... */ }
</pre>

<p>should be refactored into:</p>

<pre>
package org.example;

public class MyClass{ /* ... */ }
</pre>