Java tutorial
/* * Copyright (C) 2011-2012 Marc Boulanger * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details.* * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package com.sabdroidex.utils.json.impl; import android.os.Debug; import android.util.Log; import com.sabdroidex.data.UnknowMappingElement; import com.sabdroidex.utils.json.JSONSetter; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import java.lang.reflect.Constructor; import java.lang.reflect.Method; import java.util.Collection; import java.util.Iterator; import java.util.List; public class SimpleJSONMarshaller { private Class<?> clazz; private static final String TAG = SimpleJSONMarshaller.class.getCanonicalName(); public SimpleJSONMarshaller(Class<?> clazz) { this.clazz = clazz; } /** * This method creates an instance of the object targeted by the Class passed to the constructor, * it then tries to call all the methods with the JSONSetter annotation with the corresponding field. * * @param jsonObject * This is the JSON object that will be used to fill-up an * instance of the Class that is targeted. * @return * @throws ClassNotFoundException * @throws InstantiationException * @throws IllegalAccessException */ @SuppressWarnings("unchecked") public Object unMarshal(final JSONObject jsonObject) throws InstantiationException, IllegalAccessException { Object result = clazz.newInstance(); try { Method[] methods = clazz.getMethods(); for (int i = 0; i < methods.length; i++) { JSONSetter setter = methods[i].getAnnotation(JSONSetter.class); /** * Checking if the method has the JSONSetter annotation This * only allows one parameter per setter method */ if (setter != null) { /** * Checking the JSONType defined in the annotation */ if (setter.type() == JSONType.SIMPLE) { /** * Used for simple object (String, Integer, etc ...) */ try { Object parameter = jsonObject.get(setter.name()); methods[i].invoke(result, parameter); } catch (JSONException exception) { if (Debug.isDebuggerConnected()) { Log.d(TAG, methods[i].getName() + " " + exception.getLocalizedMessage()); } } catch (IllegalArgumentException exception) { /** * This happens if the object returned by the getter * is a null, it would be defined as a JSONObject * and thus cause an IllegalArgumentException when * calling the targeted method. * * This is yet another problem in an Android API * which is bypassed by creating an empty object of * the awaited type. */ if (Debug.isDebuggerConnected()) { Log.w(TAG, methods[i].getName() + " " + exception.getLocalizedMessage()); } try { Constructor<?>[] constructors = methods[i].getParameterTypes()[0].getConstructors(); Object parameter = null; /** * Checking all the constructor of the parameter * object. */ for (Constructor<?> constructor : constructors) { Class<?>[] params = constructor.getParameterTypes(); if (params.length == 0) { /** * If the empty constructor is found we * use it. */ parameter = constructor.newInstance(); break; } else if (params[0].isPrimitive()) { /** * If a constructor using a primitive is * found we use it, this happens for * classes that extend Number. */ parameter = constructor.newInstance(0); } } methods[i].invoke(result, parameter); } catch (Exception e) { if (Debug.isDebuggerConnected()) { Log.d(TAG, methods[i].getName() + " " + e.getLocalizedMessage()); } } } } else if (setter.type() == JSONType.JSON_OBJECT) { /** * Used for object that are instantiated from JSON * (Show, Movie, etc ...) */ try { SimpleJSONMarshaller simpleJSONMarshaller = new SimpleJSONMarshaller( methods[i].getParameterTypes()[0]); JSONObject jsonElement = jsonObject.getJSONObject(setter.name()); Object parameter = simpleJSONMarshaller.unMarshal(jsonElement); methods[i].invoke(result, parameter); } catch (JSONException exception) { if (Debug.isDebuggerConnected()) { Log.d(TAG, methods[i].getName() + " " + exception.getLocalizedMessage()); } try { Constructor<?>[] constructors = methods[i].getParameterTypes()[0].getConstructors(); Object parameter = null; /** * Checking all the constructor of the parameter * object. */ for (Constructor<?> constructor : constructors) { Class<?>[] params = constructor.getParameterTypes(); if (params.length == 0) { /** * If the empty constructor is found we * use it. */ parameter = constructor.newInstance(); break; } else if (params[0].isPrimitive()) { /** * If a constructor using a primitive is * found we use it, this happens for * classes that extend Number. */ parameter = constructor.newInstance(0); } } methods[i].invoke(result, parameter); } catch (Exception e) { if (Debug.isDebuggerConnected()) { Log.d(TAG, methods[i].getName() + " " + e.getLocalizedMessage()); } } } } else if (setter.type() == JSONType.LIST) { /** * Used for object that represent a Collection (List, * ArrayList, Vector, etc ...) */ try { JSONArray jsonArray = jsonObject.getJSONArray(setter.name()); Collection<Object> collection = null; if (methods[i].getParameterTypes()[0] == List.class) { collection = (Collection<Object>) setter.listClazz().newInstance(); } else { collection = (Collection<Object>) methods[i].getParameterTypes()[0].newInstance(); } for (int j = 0; j < jsonArray.length(); j++) { Object element = jsonArray.get(j); if (setter.objectClazz() != Void.class) { SimpleJSONMarshaller simpleJSONMarshaller = new SimpleJSONMarshaller( setter.objectClazz()); element = simpleJSONMarshaller.unMarshal((JSONObject) element); } collection.add(element); } methods[i].invoke(result, collection); } catch (JSONException exception) { if (Debug.isDebuggerConnected()) { Log.d(TAG, methods[i].getName() + " " + exception.getLocalizedMessage()); } } } else if (setter.type() == JSONType.UNKNOWN_KEY_ELEMENTS) { /** * Used for object that represent a Collection (List, * ArrayList, Vector, etc ...) and that do not have a * key that is predefined. */ try { Collection<Object> collection = null; if (methods[i].getParameterTypes()[0] == List.class) { collection = (Collection<Object>) setter.listClazz().newInstance(); } else { collection = (Collection<Object>) methods[i].getParameterTypes()[0].newInstance(); } Iterator<?> iterator = jsonObject.keys(); while (iterator.hasNext()) { String key = (String) iterator.next(); Object element = jsonObject.get(key); if (setter.objectClazz() != Void.class) { SimpleJSONMarshaller simpleJSONMarshaller = new SimpleJSONMarshaller( setter.objectClazz()); element = simpleJSONMarshaller.unMarshal((JSONObject) element); if (element instanceof UnknowMappingElement) { ((UnknowMappingElement) element).setId(key); } } collection.add(element); } methods[i].invoke(result, collection); } catch (JSONException exception) { if (Debug.isDebuggerConnected()) { Log.d(TAG, methods[i].getName() + " " + exception.getLocalizedMessage()); } } } } } } catch (Exception e) { if (Debug.isDebuggerConnected()) { Log.d(TAG, e.getLocalizedMessage()); } } return result; } }