title: Add properties to property placeholder
body: <p>I have an application where a property placeholder is used to read properties, configured in <code>applicationContext.xml</code>:</p>
  
  <pre><code>...
  &lt;context:property-placeholder
       location="classpath*:META-INF/spring/*.properties"/&gt; 
  ...
  </code></pre>
  
  <p>The application runs in an Tomcat and uses the parameter defined in context.xml.
  The application access this parameter like normal properties (<code>@Value(${cfma.applicationUrl})</code>). <em>This works</em></p>
  
  <p>In my test cases I do not have this tomcat properties, so I want to add them "manually" to the application context. But also load the normal <code>applicationContext.xml</code></p>
  
  <p>testContext.xml:</p>
  
  <pre><code>&lt;import resource="classpath:/META-INF/spring/applicationContext.xml" /&gt;
  &lt;context:property-placeholder properties-ref="simulatedTomcatProperties"/&gt;
  &lt;util:properties id="simulatedTomcatProperties"&gt;
     &lt;prop key="cfmt.applicationBaseUrl"&gt;localhost:8080/cfmt&lt;/prop&gt;
  &lt;/util:properties&gt;
  </code></pre>
  
  <p>Now I have two context:property-placeholder and this does not work (of course) – <strong>So my question is, who can I extend the properties in the “normal” property-placeholder in my test?</strong></p>
  
  <hr>
  
  <p>More Explanation of what I need:</p>
  
  <ul>
  <li>The productive environment (as well as the development environment) defines some properties via Tomcat parameter. Therefore they are not included in any properties file, but nerveless they can be accessed like normal properties (<code>@Value(${cfma.applicationUrl})</code>). Moreover there must not be any Fallback, if the properties are not defined in the Tomcat, the application must not start!</li>
  <li>In the test cases (that use the spring context) I must some how insert the property (cfma.applicationUrl) so that it can be injected in the annotated variables.
  But if I add an second <code>context:property-placeholder</code> they are not merged:</li>
  </ul>
  
  <p>@See Comments on <a href="https://jira.springsource.org/browse/SPR-4881" rel="nofollow">https://jira.springsource.org/browse/SPR-4881</a> -- they explain that behaviour.</p>
  
  <hr>
  
  <p>When I talk about Tomcat parameter I am talking about somethink like this:</p>
  
  <p>context.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;Context&gt;
      &lt;WatchedResource&gt;WEB-INF/web.xml&lt;/WatchedResource&gt;
      &lt;Parameter name="cfmt.applicationBaseUrl"
            value="http://localhost/demoApp" override="false"/&gt;
  &lt;/Context&gt;
  </code></pre>