title: Convert a property of maps with comma separated string to Map<String,List<String>>
body: <p>There is a property file which is structured as below:</p>
  
  <pre><code>prob1=a,b,c,d
  prob2=e,f,j,h
  </code></pre>
  
  <p>We want to convert it to <code>Map&lt;String,List&lt;String&gt;&gt;</code></p>
  
  <p>I know I can read a map and make a map bean from property files as:</p>
  
  <pre><code>&lt;util:properties id="probs"
  location="classpath:/configs/sample.properties" /&gt;
  </code></pre>
  
  <p>I know that I can convert the list of comma separated string to List with:</p>
  
  <pre><code>@Value("#{'${prob1}'.split(',')}") 
  private List&lt;String&gt; Probs;
  </code></pre>
  
  <p>But I don't know how can I achieve a <code>Map&lt;String,List&lt;String&gt;&gt;</code></p>