OverridePackagePrivate.qhelp

<!DOCTYPE qhelp PUBLIC
  "-//Semmle//qhelp//EN"
  "qhelp.dtd">
<qhelp>


<overview>
<p>
If a method is declared with default access (that is, not
private, protected, nor public), it can
only be overridden by methods in the same package. If a method of the same
signature is defined in a subclass in a different package, it is a
completely separate method and no overriding occurs.
</p>

<p>
Code like this can be confusing for other programmers, who have to
understand that there is no overriding relation, check that the
original programmer did not intend one method to override the other, and 
avoid mixing up the two methods by accident.
</p>

</overview>
<recommendation>

<p>In cases where there is intentionally no overriding, the best solution is to rename one or both 
of the methods to clarify their different purposes.</p>

<p>If one method is supposed to override another method that is declared with default access in
another package, the access of the method must be changed to
<code>public</code> or <code>protected</code>. Alternatively, the classes must be moved to
the same package.</p>

</recommendation>
<example>

<p>
In the following example, <code>PhotoResizerWidget.width</code> does not override 
<code>Widget.width</code> because one method is in package <code>gui</code> and one method is in
package <code>gui.extras</code>.
</p>

<sample src="OverridePackagePrivate.java" />

<p>Assuming that no overriding is intentional, one or both of the methods should be renamed. For 
example, <code>PhotoResizerWidget.width</code> would be better named 
<code>PhotoResizerWidget.newPhotoWidth</code>.</p>

</example>
<references>


<li>
Help - Eclipse Platform:
<a href="https://help.eclipse.org/2020-12/advanced/content.jsp?topic=/org.eclipse.jdt.doc.user/reference/preferences/java/compiler/ref-preferences-errors-warnings.htm">Java Compiler Errors/Warnings Preferences</a>.
</li>
<li>
Java Language Specification:
<a href="https://docs.oracle.com/javase/specs/jls/se11/html/jls-8.html#jls-8.4.8.1">8.4.8.1 Overriding (by Instance Methods)</a>.
</li>


</references>
</qhelp>