title: How to print the value of a map in ireport?
body: <p>I pass <code>Map&lt;String, Set&lt;Object&gt;&gt;</code> object as parameter to my ireport.
  I want to print the  value <code>"Set&lt;Object&gt;"</code> on the custom created group if key in the map is equal to a field.</p>
  
  <p><strong>Any Idea how to do it?</strong>
  thanks in advance</p>
  
  <pre><code>HashMap&lt;String,Object&gt; parameters = new HashMap&lt;String,Object&gt;();
  parameters.put("PA_CHING",retreivePaChingMapping());
  
  public Map&lt;String, Set&lt;Object&gt;&gt; retreivePaChingMapping() {
          Map&lt;String, Set&lt;Object&gt;&gt; paChing = GenericsUtil.makeMap();
          //adds the object to paChing here 
          return paChing;
      }
  </code></pre>
  
  <p><strong>In IReport:</strong></p>
  
  <p><strong>parameter name:</strong> PA_CHING</p>
  
  <p><strong>parameter class type:</strong> java.util.HashMap</p>
  
  <p><strong>Default value expression:</strong> i don't know what to put here.</p>
  
  <p><strong>Expression of text field in ireport:</strong></p>
  
  <pre><code>$P{paChing}.containsKey( $F{id} ) ? getChing() : "null";
  
  private void String getChing(){
      StringBuilder ching = new StringBuilder();
      $P{PA_CHInG}.get( $F{id} ).iterator().hasNext()?ching.append($P{PA_CHING}.get( $F{id} ).iterator().next):"";
  
      return ching;
  }
  </code></pre>