SharedPreferences工具类，作为存储和获取data下相关文件工具类，对SharedPreferences进行封装，使其使用更简单。

    import java.lang.reflect.InvocationTargetException;  
    import java.lang.reflect.Method;  
    import java.util.Map;  
      
    import android.content.Context;  
    import android.content.SharedPreferences;  
      
    public class SPUtils  
    {  
        public SPUtils()  
        {  
            /* cannot be instantiated */  
            throw new UnsupportedOperationException("cannot be instantiated");  
        }  
      
        /** 
         * 保存在手机里面的文件名 
         */  
        public static final String FILE_NAME = "share_data";  
      
        /** 
         * 保存数据的方法，我们需要拿到保存数据的具体类型，然后根据类型调用不同的保存方法 
         *  
         * @param context 
         * @param key 
         * @param object 
         */  
        public static void put(Context context, String key, Object object)  
        {  
      
            SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                    Context.MODE_PRIVATE);  
            SharedPreferences.Editor editor = sp.edit();  
      
            if (object instanceof String)  
            {  
                editor.putString(key, (String) object);  
            } else if (object instanceof Integer)  
            {  
                editor.putInt(key, (Integer) object);  
            } else if (object instanceof Boolean)  
            {  
                editor.putBoolean(key, (Boolean) object);  
            } else if (object instanceof Float)  
            {  
                editor.putFloat(key, (Float) object);  
            } else if (object instanceof Long)  
            {  
                editor.putLong(key, (Long) object);  
            } else  
            {  
                editor.putString(key, object.toString());  
            }  
      
            SharedPreferencesCompat.apply(editor);  
        }  
      
        /** 
         * 得到保存数据的方法，我们根据默认值得到保存的数据的具体类型，然后调用相对于的方法获取值 
         *  
         * @param context 
         * @param key 
         * @param defaultObject 
         * @return 
         */  
        public static Object get(Context context, String key, Object defaultObject)  
        {  
            SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                    Context.MODE_PRIVATE);  
      
            if (defaultObject instanceof String)  
            {  
                return sp.getString(key, (String) defaultObject);  
            } else if (defaultObject instanceof Integer)  
            {  
                return sp.getInt(key, (Integer) defaultObject);  
            } else if (defaultObject instanceof Boolean)  
            {  
                return sp.getBoolean(key, (Boolean) defaultObject);  
            } else if (defaultObject instanceof Float)  
            {  
                return sp.getFloat(key, (Float) defaultObject);  
            } else if (defaultObject instanceof Long)  
            {  
                return sp.getLong(key, (Long) defaultObject);  
            }  
      
            return null;  
        }  
      
        /** 
         * 移除某个key值已经对应的值 
         *  
         * @param context 
         * @param key 
         */  
        public static void remove(Context context, String key)  
        {  
            SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                    Context.MODE_PRIVATE);  
            SharedPreferences.Editor editor = sp.edit();  
            editor.remove(key);  
            SharedPreferencesCompat.apply(editor);  
        }  
      
        /** 
         * 清除所有数据 
         *  
         * @param context 
         */  
        public static void clear(Context context)  
        {  
            SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                    Context.MODE_PRIVATE);  
            SharedPreferences.Editor editor = sp.edit();  
            editor.clear();  
            SharedPreferencesCompat.apply(editor);  
        }  
      
        /** 
         * 查询某个key是否已经存在 
         *  
         * @param context 
         * @param key 
         * @return 
         */  
        public static boolean contains(Context context, String key)  
        {  
            SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                    Context.MODE_PRIVATE);  
            return sp.contains(key);  
        }  
      
        /** 
         * 返回所有的键值对 
         *  
         * @param context 
         * @return 
         */  
        public static Map<String, ?> getAll(Context context)  
        {  
            SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                    Context.MODE_PRIVATE);  
            return sp.getAll();  
        }  
      
        /** 
         * 创建一个解决SharedPreferencesCompat.apply方法的一个兼容类 
         *  
         * @author zhy 
         *  
         */  
        private static class SharedPreferencesCompat  
        {  
            private static final Method sApplyMethod = findApplyMethod();  
      
            /** 
             * 反射查找apply的方法 
             *  
             * @return 
             */  
            @SuppressWarnings({ "unchecked", "rawtypes" })  
            private static Method findApplyMethod()  
            {  
                try  
                {  
                    Class clz = SharedPreferences.Editor.class;  
                    return clz.getMethod("apply");  
                } catch (NoSuchMethodException e)  
                {  
                }  
      
                return null;  
            }  
      
            /** 
             * 如果找到则使用apply执行，否则使用commit 
             *  
             * @param editor 
             */  
            public static void apply(SharedPreferences.Editor editor)  
            {  
                try  
                {  
                    if (sApplyMethod != null)  
                    {  
                        sApplyMethod.invoke(editor);  
                        return;  
                    }  
                } catch (IllegalArgumentException e)  
                {  
                } catch (IllegalAccessException e)  
                {  
                } catch (InvocationTargetException e)  
                {  
                }  
                editor.commit();  
            }  
        }  
      
    }