title: How Do I Search Deeply Inside A Map, Java?
body: <p>I'm very new to Java. I have written code that uses a Red Black tree : </p>
  
  <pre><code>            TreeMap test = new TreeMap();
              Map mainMap = new HashMap&lt;&gt;();
              Map tempMap = new HashMap&lt;&gt;();
              List&lt;Integer&gt; list = new ArrayList&lt;&gt;();
  
  
              tempMap.put("Visa Credit Card",447747);
              list.add(421323);
              list.add(421630);
              list.add(455451);
              list.add(469375);
              tempMap.put("Visa Debit card",list);
  
              tempMap.put("Master Card Credit Card",523951);
              tempMap.put("Master Debit Card",5399);
  
              mainMap.put("ICCI",tempMap);
              mainMap.put("Next",1234);
  
              test.put("Values",mainMap);
  
              System.out.println(mainMap);
  </code></pre>
  
  <p>Which is printing out the following : </p>
  
  <pre><code>{Next=1234, ICCI={Master Card Credit Card=523951, Visa Debit card=[421323, 421630, 455451, 469375], Master Debit Card=5399, Visa Credit Card=447747}}
  </code></pre>
  
  <p>As I have expected. But in this map, I need to search for some values in the map, say for example <code>455451</code>. If doing so I should get output as :</p>
  
  <p><code>Visa Debit card, ICCI</code>.</p>
  
  <p>Is it possible to do a search over the maps? </p>
  
  <p>Thanks in advance.</p>