Gson Sample

public class JamNotification {
	@SerializedName("wall_comment")
  	public JamFeedComment feedComment = new JamFeedComment();

  	/* Variable name for internal use */
  	@SerializedName("member_id")
  	private int memberId;
  	
  	@SerializedName("obj_id")
  	private int objId;
  	
  	
  	// if the json key is equase the field name, we needn't this anotation 		//@SerializedName("id")
  	private int id;
  	
  	@SerializedName("sender_id")
 	 	private int senderId;
  	
  	// wrapper class
  	public class JamFeedComment {
    	private String comment;

    	@SerializedName("feed_id")
    	private int feedId;

    	public String getComment() {
        	return comment;
    	}

    	public void setComment(String comment) {
        	this.comment = comment;
    	}

    	public int getFeedId() {
        	return feedId;
    	}

    	public void setFeedId(int i) {
        	this.feedId = i;
    	}
  }
  
  public static void main(args[]) {
  
  	// Simple fromJson, toJson API
	private Gson gson = new Gson();
	
	JamNotification notification = new JamNotification();
	// set fields…
	String jsonStr = gson.toJson();
	
	JamNotification notification1 = gson.fromJson(jsonStr, JamNotification.class);
  }
  	
}