json 实体互转, list json互转 ,List<实体> 转List<Object> , List<Objcet> 转List<Map> map 转实体 ， map转json

//    json 实体互转, list json互转 ,List<实体> 转List<Object> , List<Objcet> 转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("测试");
b.setStatus(false);
Brand b1 = new Brand();
b1.setBrandId(2);
b1.setBrandName("测试2");
b1.setStatus(false);
Brand b2 = new Brand();
b2.setBrandId(3);
b2.setBrandName("测试3");
b2.setStatus(false);

brandList.add(b1);
brandList.add(b2);
brandList.add(b);

/**
*
*实体转为json
*/
String s = JSONObject.toJSONString(b);
System.out.println(s);

/**
*
*json转为实体
*/
Brand brand = JSONObject.parseObject(s, Brand.class);
System.out.println(brand + "==============");

/**
*
*list集合转json
*/
String s1 = JSON.toJSONString(brandList);
System.out.println(s1 + "999999");
//json 转list
List<Brand> brands = JSONObject.parseArray(s1, Brand.class);
System.out.println(brands);

}

/**
* List<实体>转为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> 转为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  转  json
*	导  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();

}

另外一种map 转json 	导  com.alibaba.druid.support.json;

String s = JSONUtils.toJSONString(map)

/**
* map   转   实体
*/
public static <T> T toBean(Class<T> clazz, Map map) {
T obj = null;
try {
BeanInfo beanInfo = Introspector.getBeanInfo(clazz);
obj = clazz.newInstance(); // 创建 JavaBean 对象

// 给 JavaBean 对象的属性赋值
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 起来，这样当一个属性赋值失败的时候就不会影响其他属性赋值。
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("字段映射失败");
}
}
}
} catch (IllegalAccessException e) {
System.out.println("实例化 JavaBean 失败");
} catch (IntrospectionException e) {
System.out.println("分析类属性失败");
} catch (IllegalArgumentException e) {
System.out.println("映射错误");
} catch (InstantiationException e) {
System.out.println("实例化 JavaBean 失败");
}
return (T) obj;
}
}