title: Passing a dir into a bean constructor
body: <p>I have the following bean setup</p>
  
  <pre><code>    &lt;bean id="server-engine"
      class="RuleEngineRESJSE"&gt;
      &lt;constructor-arg index="0" value="package.rulesengine.log" /&gt;
  &lt;/bean&gt; 
  </code></pre>
  
  <p>However I get the error:</p>
  
  <pre><code>Constructor threw exception; nested exception is java.lang.IllegalStateException: The value of rulesLogProperty was not found
  </code></pre>
  
  <p>The constructor simply takes a string argument for the rulesLogProperty</p>
  
  <pre><code>    public RuleEngineRESJSE(String rulesLogProperty) throws IOException {
  
      if(rulesLogProperty == null)
          throw new IllegalStateException("The rulesLogProperty value is expected");
  
      this.log = System.getProperty(rulesLogProperty);
  
      if(log == null)
          throw new IllegalStateException("The value of rulesLogProperty was not found");
  
      init();
  }
  </code></pre>
  
  <p>so I see the exception is being thrown. which would make me think that:</p>
  
  <pre><code>this.log = System.getProperty(rulesLogProperty)
  </code></pre>
  
  <p>is the issue but why?</p>