title: how to add Json header in json array parsed from Java Object
body: <p>i found many examples to parse java object to Json.
  Thanks for that.But i have one issue, i want Json in following format</p>
  
  <pre><code>{
    "parent":
    {
      "sub-parent-1":
      {
        "child-1": 1,
        "child-2": 2
      },
      "sub-parent-2":
      {
        "child-2": 3
      }
    }
  }
  </code></pre>
  
  <p>Is it possible with java.
  Please answer.Thanks in advanced..</p>