title: define a string in spring context
body: <p>I have three (A,B,C) spring context.xml, A is for the basic configuration, B and C import the A.</p>
  
  <p>In a bean on A I have:</p>
  
  <pre>
  &lt;bean class="com.example.Ex"&gt;
      &lt;property name="aString" value="${myString}" /&gt;
  &lt;/bean&gt;
  </pre>
  
  <p>now I want to define the property myString on B and C context, is possible to do it without create and loads two different properties file?</p>