1-Old-Way.java

private int id;
private String name;
private String description;
private double fee;
private int startAge;
private int endAge;
private int size;
private boolean adultOnly;
private int min;
private int max;
private double lat;
private double lng;
private ActivityModel activity;
private Date startDate;
private Date endDate;
private int registrationCount;
private int friendCount;

public EventModel() { 
	super(); 
} 

public EventModel(JSONObject jsonObject) { 
	super(jsonObject); 
} 

@Override 
public void mapToClass(String key, Object value) { 
	if (key.equals("id")) { 
		this.id = (Integer)value; 
	} else if (key.equals("name")) { 
		this.name = (String)value; 
	} else if (key.equals("description")) { 
		this.description = (String)value;
	} else if (key.equals("fee")) { 
		this.fee = Double.parseDouble(value.toString()); 
	} else if (key.equals("start_age")) { 
		this.startAge = (Integer)value; 
	} else if (key.equals("end_age")) { 
		this.endAge = (Integer)value; 
	} else if (key.equals("adult_only")) { 
		this.adultOnly = (Boolean)value; 
	} else if (key.equals("size")) { 
		this.size = (Integer)value;
	} else if (key.equals("min")) { 
		this.min = (Integer)value; 
	} else if (key.equals("max")) { 
		this.max = (Integer)value; 
	} else if (key.equals("lat")) { 
		this.lat = Double.parseDouble(value.toString()); 
	} else if (key.equals("lng")) { 
		this.lng = Double.parseDouble(value.toString()); 
	} else if (key.equals("images")) { 

	} else if (key.equals("thumbnails")) { 

	} else if (key.equals("activity")) { 
		this.activity = ProtocolModel.createModel(ActivityModel.class, value.toString());
	} else if (key.equals("start_date")) { 
		this.startDate = BaseModel.stringToDate(value.toString()); 
	} else if (key.equals("end_date")) { 
		this.endDate = BaseModel.stringToDate(value.toString()); 
	} else if (key.equals("instructor")) { 

	} else if (key.equals("registration_count")) { 
		this.registrationCount = (Integer)value; 
	} else if (key.equals("friend_count")) { 
		this.friendCount = (Integer)value; 
	} 
} 

2-New-Way.java

@MapConfig(key = "id") private int id;
@MapConfig(key = "name") private String name;
@MapConfig(key = "description") private String description;
@MapConfig(key = "fee") private double fee;
@MapConfig(key = "start_age") private int startAge;
@MapConfig(key = "end_age") private int endAge;
@MapConfig(key = "size") private int size;
@MapConfig(key = "adult_only") private boolean adultOnly;
@MapConfig(key = "min") private int min;
@MapConfig(key = "max") private int max;
@MapConfig(key = "lat") private double lat;
@MapConfig(key = "lng") private double lng;
@MapModelConfig(key = "activity", modelClass = ActivityModel.class) private ActivityModel activity;
@MapConfig(key = "start_date", format = "date") private Date startDate;
@MapConfig(key = "end_date", format = "date") private Date endDate;
@MapConfig(key = "registration_count") private int registrationCount;
@MapConfig(key = "friend_count") private int friendCount;

3-Custom-Formats.java

ProtocolModelFormats.set("date", new MapFormat() {

@Override
	public Object format(Object value) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy'-'MM'-'dd'T'HH':'mm':'ssZ");
		try {
			return sdf.parse(value.toString());
		} catch (ParseException e) {e.printStackTrace();}
		return null;
	}

});