//    json 實體互轉, list json互轉 ,List<實體> 轉List<Object> , List<Objcet> 轉List<Map>          使用alibaba的json工具包
     import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.dao.model.Brand;
import java.util.ArrayList;
import java.util.List;
/**
     * Created by chengda on 2017/2/23.
 
     */
public class JsonTest {

        public static void main(String[] args) {
            List<Brand> brandList = new ArrayList<Brand>();
Brand b = new Brand();
b.setBrandId(1);
b.setBrandName("測試");
b.setStatus(false);
Brand b1 = new Brand();
b1.setBrandId(2);
b1.setBrandName("測試2");
 
b1.setStatus(false);
Brand b2 = new Brand();
b2.setBrandId(3);
b2.setBrandName("測試3");
b2.setStatus(false);
brandList.add(b1);
brandList.add(b2);
brandList.add(b);
/**
             *
             *實體轉為json
             */
String s = JSONObject.toJSONString(b);
System.out.println(s);
/**
             *
 
             *json轉為實體
             */
Brand brand = JSONObject.parseObject(s, Brand.class);
System.out.println(brand + "==============");
/**
             *
             *list集合轉json
             */
String s1 = JSON.toJSONString(brandList);
System.out.println(s1 + "999999");
//json 轉list
List<Brand> brands = JSONObject.parseArray(s1, Brand.class);
System.out.println(brands);
}


        /**
         * List<實體>轉為list<Object>
*
         * @param t
* @return
*/
public List<Object> beanToObject(List<?> t) {
            List<Object> o = new ArrayList<Object>();
Iterator<?> it = t.iterator();
            while (it.hasNext()) {
                o.add(it.next());
}

            return o;
}


        /**
         * List<objcet> 轉為List<Map>
*
         * @param object
* @return
* @throws Exception
         */
public List<Map> beanToMap(List<Object> object) throws Exception {
            List<Map> maps = new ArrayList<Map>();
            for (Object o : object) {
                String s = JSON.toJSONString(o);
Map map = JSONObject.parseObject(s, Map.class);
maps.add(map);
}
            return maps;
}

        /**
         *   map  轉  json
	 *	導  import net.sf.json.JSONObject;
         */
public String mapToJson(){
            Map<String,String> map = new HashMap<String,String>();
map.put("huahua1","huahua1");
map.put("huahua2","huahua2");
map.put("huahua3","huahua3");
JSONObject smsparam = JSONObject.fromObject(smsParam);
            return smsparam.toJSONString();
}


        另外一種map 轉json 	導  com.alibaba.druid.support.json;	

	String s = JSONUtils.toJSONString(map)



        /**
         * map   轉   實體
         */
public static <T> T toBean(Class<T> clazz, Map map) {
            T obj = null;
            try {
                BeanInfo beanInfo = Introspector.getBeanInfo(clazz);
obj = clazz.newInstance(); // 建立 JavaBean 物件
                // 給 JavaBean 物件的屬性賦值
PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
                for (int i = 0; i < propertyDescriptors.length; i++) {
                    PropertyDescriptor descriptor = propertyDescriptors[i];
String propertyName = descriptor.getName();
                    if (map.containsKey(propertyName)) {
                        // 下面一句可以 try 起來，這樣當一個屬性賦值失敗的時候就不會影響其他屬性賦值。
Object value = map.get(propertyName);
                        if ("".equals(value)) {
                            value = null;
}
                        Object[] args = new Object[1];
args[0] = value;
                        try {
                            descriptor.getWriteMethod().invoke(obj, args);
} catch (InvocationTargetException e) {
                            System.out.println("欄位對映失敗");
}
                    }
                }
            } catch (IllegalAccessException e) {
                System.out.println("例項化 JavaBean 失敗");
} catch (IntrospectionException e) {
                System.out.println("分析類屬性失敗");
} catch (IllegalArgumentException e) {
                System.out.println("對映錯誤");
} catch (InstantiationException e) {
                System.out.println("例項化 JavaBean 失敗");
}
            return (T) obj;
}
    }