ComplexPreferences.java

package com.example.agathe.tsgtest;

import android.content.Context;
import android.content.SharedPreferences;

import com.google.gson.Gson;

public class ComplexPreferences {

	private static ComplexPreferences complexPreferences;
	private SharedPreferences preferences;
	private SharedPreferences.Editor editor;
	private static Gson GSON = new Gson();

	private ComplexPreferences(Context context, String namePreferences, int mode) {
		if (namePreferences == null || namePreferences.equals("")) {
			namePreferences = "complex_preferences";
		}
		preferences = context.getSharedPreferences(namePreferences, mode);
		editor = preferences.edit();
	}

	public static ComplexPreferences getComplexPreferences(Context context,
			String namePreferences, int mode) {

		if (complexPreferences == null) {
			complexPreferences = new ComplexPreferences(context,
					namePreferences, mode);
		}

		return complexPreferences;
	}

	public void putObject(String key, Object object) {
		if(object == null){
			throw new IllegalArgumentException("object is null");
		}
		
		if(key.equals("") || key == null){
			throw new IllegalArgumentException("key is empty or null");
		}
		
		editor.putString(key, GSON.toJson(object));
	}

	public void commit() {
		editor.commit();
	}

	public <T> T getObject(String key, Class<T> a) {
	
		String gson = preferences.getString(key, null);
		if (gson == null) {
			return null;
		} else {
			try{
				return GSON.fromJson(gson, a);
			} catch (Exception e) {
				throw new IllegalArgumentException("Object storaged with key " + key + " is instanceof other class");				
			}
		}
	}
		
	
}