title: Jackson field based serialization
body: <p>I think Jackson does method based serialization, is there any way I could make it field based?</p>
  
  <p>Ex:</p>
  
  <pre><code>class Bean {
      Integer i;
      String s;
  
      public Integer getI() { return this.i; }
      public void setI(Integer i) { this.i = i; }
      public bool isSetI() { return this.i != null; }
  
      // same for s as well
  }
  </code></pre>
  
  <p>The output JSON has "i" and "setI". Is there anyway I could override this to get only "i"?
  Also it would be great if there was a way to do this without adding any annotations to the class (they are auto generated).</p>