title: ObjectMapper writeValueAsString() method convert field name into lowercase
body: <p>I have entity named as Data</p>
  
  <pre><code>class Data
  {
      String Name;
      int Age;
      // Constructor &amp; Getters &amp; Setters
  }
  </code></pre>
  
  <p>When I use <code>ObjectMapper</code> </p>
  
  <pre><code>Data objData = new Data("XYZ",3);
  ObjectMapper mapper = new ObjectMapper();
  System.out.println(mapper.writeValueAsString(objData));
  </code></pre>
  
  <p>Output :</p>
  
  <pre><code>{"name":"XYZ","age":3}
  </code></pre>
  
  <p>it convert field name into lower case.</p>
  
  <p>How can I get output like </p>
  
  <pre><code>{"Name":"XYZ","Age":3}
  </code></pre>