title: Filter a map value using java 8 streams
body: <p>I have a map as below and wanted to retrieve the values of the inner map using the key.</p>
  
  <pre><code>&lt;bean id="testMap" class="java.util.HashMap"&gt;
      &lt;constructor-arg&gt;
        &lt;map&gt;
          &lt;entry key="A" value="AA" /&gt;
          &lt;entry key="B"&gt;
            &lt;map&gt;
              &lt;entry key="B1" value="B11" /&gt;
              &lt;entry key="B2" value="B22" /&gt;
              &lt;entry key="B3" value="B33" /&gt;
            &lt;/map&gt;
          &lt;/entry&gt;
        &lt;/map&gt;
      &lt;/constructor-arg&gt;
    &lt;/bean&gt;
  </code></pre>
  
  <p>below code prints the 1st level, how to print the inner map value?</p>
  
  <pre><code>myMap.entrySet().stream().filter(map -&gt; map.getKey().equals("B")).forEach(p -&gt; System.out.println(p));
  </code></pre>