ParentShouldNotUseAbstractClass.qhelp

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


<overview>
<p>
A non-abstract Spring bean that is a parent of other beans must not specify an abstract class. Doing so causes an error during
bean instantiation.
</p>

</overview>
<recommendation>
<p>
Make sure that a non-abstract bean does not specify an abstract class, by 
doing one of the following:</p>

<ul>
    <li>Specify that the bean is also abstract by adding <code>abstract="true"</code> to the bean specification.</li>
    <li>If possible, update the class that is specified by the bean so that it is not abstract.</li>
</ul>

<p>You can also make the XML parent bean definition abstract and remove any references
from it to any class (in which case it becomes a pure bean template). Note that, like an 
abstract class, an abstract bean cannot be used on its own and only 
provides property and constructor definitions to its children.
</p>

</recommendation>
<example>

<p>In the following example, the bean <code>wrongConnectionPool</code> is using an abstract class, 
<code>ConnectionPool</code>, which causes an error. Instead, the bean should be declared 
<code>abstract</code>, as shown in the definition of <code>connectionPool</code>.</p>

<sample src="ParentShouldNotUseAbstractClass.xml" />

</example>
<references>


<li>
Spring Framework Reference Documentation 3.0: <a href="http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/beans.html#beans-child-bean-definitions">3.7 Bean definition inheritance</a>.
</li>


</references>
</qhelp>