JSONMappedObject.java

package com.tethik.json;

import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;




public abstract class JSONMappedObject {	
	
	private static boolean debug = false;
	
	protected Object getValue(Class<?> type, Object obj) throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException, JSONException
	{
		Object value;
		
		if(JSONMappedObject.class.isAssignableFrom(type)) {
			// Recursion
			if(debug) System.out.println("Object found");				
			Constructor<?> constructor = type.getConstructor(JSONObject.class);
			if(debug) System.out.println("Constructor created");			
			value = constructor.newInstance((JSONObject) obj);						
		} else if(type.isEnum()) {
			// Enums
			if(debug) System.out.println("Enum found");
			value = Enum.valueOf((Class<Enum>) type, (String) obj);				
		} else if(type.isArray()) {
			JSONArray array = (JSONArray) obj;
			Object[] objects = new Object[array.length()];
			for(int i = 0; i < array.length(); i++)
				objects[i] = getValue(type.getComponentType(), array.get(i));
			value = objects;
		} else {
			// Basic type. Or error :(
			if(debug) System.out.println("Basic found");
			value = obj;
		}
		
		return value;		
	}
	
	protected Object getValue(Class<?> type, String key, JSONObject obj) throws NoSuchMethodException, SecurityException, JSONException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException
	{				
		Object value;
		
		if(JSONMappedObject.class.isAssignableFrom(type)) {
			// Recursion
			if(debug) System.out.println("Object found");				
			Constructor<?> constructor = type.getConstructor(JSONObject.class);
			if(debug) System.out.println("Constructor created");			
			value = constructor.newInstance(obj.getJSONObject(key));						
		} else if(type.isEnum()) {
			// Enums
			if(debug) System.out.println("Enum found");
			value = Enum.valueOf((Class<Enum>) type, obj.getString(key));				
		} else if(type.isArray()) {
			JSONArray array = obj.getJSONArray(key);
			Object objects = type.cast(Array.newInstance(type.getComponentType(), array.length()));
			for(int i = 0; i < array.length(); i++)
				Array.set(objects, i, type.getComponentType().cast(getValue(type.getComponentType(), array.get(i))));
			value = objects;
		} else {
			// Basic type. Or error :(
			if(debug) System.out.println("Basic found");
			value = obj.get(key);
		}
		
		return value;
	}
	
	protected void parseJson(JSONObject obj) throws JSONException, IllegalArgumentException, IllegalAccessException, InstantiationException, NoSuchMethodException, SecurityException, InvocationTargetException {
		if(debug) System.out.println("parseJson called on " + this.getClass().getName());
		Field[] fields = this.getClass().getDeclaredFields();
		
		for(Field field : fields) {
			field.setAccessible(true);
			if(debug) System.out.println("Checking " + field.getName());
			if(!field.isAnnotationPresent(JSONObj.class))			
				continue;
			
			String key = field.getName();
			Class<?> type = field.getType();
			if(debug) System.out.println("Annotation found on " + key + " type: " + type.getName());
			
			Object value = getValue(type, key, obj);
	
			field.set(this, value);
			if(debug) System.out.println("Field set to " + value);
		}	
	}
	
	public JSONMappedObject(JSONObject obj) throws JSONException
	{
		try {
			parseJson(obj);
		} catch (IllegalArgumentException | IllegalAccessException | InstantiationException | NoSuchMethodException | SecurityException | InvocationTargetException e) {
			throw new JSONException(e);
		}
	}
}