[Android] 数据实体的自动存取--SharedPreferences篇

本例代码以SharedPreferences为数据存取载体。
利用SharedPreferences存取一个数据，步骤如下：
[java]
SharedPreferences sharedPre = getSharedPreferences(name, mode);
存:
SharedPreferences.Editor editor = sharedPre.edit();

editor.put(key,value);
editor.commit();
取：
value = sharedPre.get(key,defaultValue);
观察以上，存取的关键是规范好对<key,value>的操作。其中key为字符串为预先定义好的。如果有多组<key,value>,则为每组想好key的名称也是一件挺纠结的事。

本文自动读取的核心在于直接使用数据实体的属性名做为key值，在存取时遍历数据实例的属性，使用反射类读取属性的名称,对属性值进行写出或写入。
首先，事先定义好可处理的存取数据类型如下：
[java]
public static final int CLZ_BYTE = 1;
public static final int CLZ_SHORT = 2;
public static final int CLZ_INTEGER = 3;
public static final int CLZ_LONG = 4;
public static final int CLZ_STRING = 5;
public static final int CLZ_BOOLEAN = 6;
public static final int CLZ_FLOAT = 7;
public static final int CLZ_DOUBLE = 8;
public static final Map<Class<?>, Integer> TYPES;
static {
    TYPES = new HashMap<Class<?>, Integer>();
    TYPES.put(byte.class, CLZ_BYTE);
    TYPES.put(short.class, CLZ_SHORT);
    TYPES.put(int.class, CLZ_INTEGER);
    TYPES.put(long.class, CLZ_LONG);
    TYPES.put(String.class, CLZ_STRING);
    TYPES.put(boolean.class, CLZ_BOOLEAN);
    TYPES.put(float.class, CLZ_FLOAT);
    TYPES.put(double.class, CLZ_DOUBLE);
}
写出：
[java]
private void doSave(GoodsBean bean) {
    SharedPreferences sharedPre = getSharedPreferences(GoodsBean.class.getName(), Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPre.edit();
    Class<? extends GoodsBean> clazz = bean.getClass();
    Field[] arrFiled = clazz.getDeclaredFields();
    try {
        for (Field f : arrFiled) {
            Log.d("ANDROID_LAB", "type[" + f.getType() + "] name[" + f.getName() + "]");
            int type = TYPES.get(f.getType());
            switch (type) {
            case CLZ_BYTE:
            case CLZ_SHORT:
            case CLZ_INTEGER:
                editor.putInt(f.getName(), f.getInt(bean));
                break;
            case CLZ_LONG:
                editor.putLong(f.getName(), f.getLong(bean));
                break;
            case CLZ_STRING:
                editor.putString(f.getName(), (String) f.get(bean));
                break;
            case CLZ_BOOLEAN:
                editor.putBoolean(f.getName(), f.getBoolean(bean));
                break;
            case CLZ_FLOAT:
                editor.putFloat(f.getName(), f.getFloat(bean));
                break;
            case CLZ_DOUBLE:
                editor.putFloat(f.getName(), (float) f.getDouble(bean));
                break;
            }
        }
        editor.commit();
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (IllegalAccessException e) {
        e.printStackTrace();
    }
}
读入：
[java]
private GoodsBean doRead() {
    SharedPreferences sharedPre = getSharedPreferences(GoodsBean.class.getName(), Context.MODE_PRIVATE);
    GoodsBean bean = new GoodsBean();
    Class<? extends GoodsBean> clazz = bean.getClass();
    Field[] arrFiled = clazz.getDeclaredFields();
    try {
        for (Field f : arrFiled) {
            int type = TYPES.get(f.getType());
            switch (type) {
            case CLZ_BYTE:
                byte byteValue = (byte) sharedPre.getInt(f.getName(), 0);
                f.set(bean, byteValue);
                break;
            case CLZ_SHORT:
                short shortValue = (short) sharedPre.getInt(f.getName(), 0);
                f.set(bean, shortValue);
                break;
            case CLZ_INTEGER:
                int intValue = sharedPre.getInt(f.getName(), 0);
                f.set(bean, intValue);
           &n

补充：移动开发 , Android ,