根據物件中欄位屬性值，動態呼叫相應的get方法

#### 舉個例子，把物件GoodsVO中的欄位作為key, get方法作為value,全部存放在Map中.

//商品物件
public class GoodsVO {

    /**
     * 品牌ID
     */
    private Long brandId;

    /**
     * 品牌名稱
     */
    private String brandName;

    /**
     * 商品ID
     */
    private Long goodsId;

    /**
     * 商品標籤
     */
 

    private List<String> goodsTagList;

    /**
     * 庫存
     */
    private Integer actualStore;

    /**
     * 狀態 0 下架 1 上架
     */
    private Integer status;

    public GoodsVO() {
    }

    public GoodsVO(String brandName, Long brandId,Long goodsId,  Integer actualStore, Integer status, List<String> goodsTagList) {
        this
 
.brandName = brandName;
        this.goodsId = goodsId;
        this.brandId = brandId;
        this.actualStore = actualStore;
        this.status = status;
        this.goodsTagList = goodsTagList;
    }
set/get。。。。
}

實際情況我們可以採用笨方法，一個一個的put到map中，但是這不是我們今天想要學習的。

採用java反射實現

/**
 * @author zhanghuilong
 * @desc
 

 * @since 2018/06/12
 */
public class Test {

    public static void main(String[] args) throws IllegalAccessException, InstantiationException {

        GoodsVO goodsVO = new GoodsVO("蘋果",1L,100L,101, 1,asList("����-Apple","果粉","Mac系列\n"));
        Class<?> aClass = GoodsVO.class;
        Field[] fields = aClass.getDeclaredFields();
        Map<Object, Object> map = new HashMap<>();
        for (Field field  : fields){
            map.put(field.getName() , getResult(field.getName() , goodsVO));
        }

        System.out.println(JSON.toJSONString(map));
    }


    private static Object getResult(Object fieldName, GoodsVO goodsVO) {
        try {
            Class<?> aClass = goodsVO.getClass();
            Field declaredField = aClass.getDeclaredField(fieldName.toString());
            declaredField.setAccessible(true);
            PropertyDescriptor pd = new PropertyDescriptor(declaredField.getName(), aClass);
            Method readMethod = pd.getReadMethod();

            return readMethod.invoke(goodsVO);
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IntrospectionException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        return null;
    }
}

輸出結果：