FastJson 和JackJson 的用法和区别

￡神魔★判官ぃ 2024-04-20 08:45 67阅读 0赞

先说不同点

1.  当对象中有属性为null的时候,fastjson默认是除null的,转后的字符串是不包含为null的那个属性  (见31行)

如果转map会丢失属性 (见40行)

2.相反的jackjson则不会丢失属性,jackjson会保留为null的那条属性 (见50行)

3.同样是取某个值.fastjson取出来的值不带" " 双引号 ,jackjson带" " 双引号 (见34  63 行)

import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.JSONObject;
    import com.cnczsq.mall.elephant.v1.model.User;
    import com.fasterxml.jackson.core.type.TypeReference;
    import com.fasterxml.jackson.databind.JsonNode;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import java.util.ArrayList;
    import java.util.Arrays;
    import java.util.List;
    import java.util.Map;
    /**
     * @author : zhang sq
     * @date : 2019/9/10 11:15
     **/
    public class FastTest {
        public static void main(String[] args) {
            //FastJson  start
            String result="{\"resultCode\":\"00000000\",\"resultMsg\":\"SUCCESS\",\"data\":\n" +
                    "{\"accountId\":\"15674752678246536\",\"username\":\"空白°\",\"nickname\":\"空白°\",\"safeUsername\":null,\"email\":null,\"cellPhone\":\"15901414066\",\n" +
                    "\"identifier\":\"15674752678246536\",\"verifyCode\":null,\"token\":null,\"password\":\"5EF07368259A14E0597DE114636DEF7C\",\"st\":null,\"passMd5ed\":false,\n" +
                    "\"newPassword\":null,\"hasPwd\":false,\"wayRegister\":null,\"userType\":\"无\",\"parentId\":null,\"state\":1,\"enable\":null,\"freezeOpinion\":null,\"ntfl\":\"0\",\n" +
                    "\"remoteHost\":null,\"lastLoginAt\":null,\"createAt\":\"2019-09-03 09:47:47\",\"updateAt\":\"2019-09-09 15:34:40\",\"wxUnionId\":null,\"qqOpenId\":null,\n" +
                    "\"wbUId\":null,\"city\":\"北京\",\"birthday\":0,\"professional\":null,\"gender\":2,\"signature\":null,\n" +
                    "\"avatar\":\"group1/M00/00/24/Cg4BSl1vJ9SAeWBHAAGe2f-xqGs298.jpg\"}}";
            //一个对象里面套一个对象,  去对象里面对象的某个值
            String string = JSONObject.parseObject(result).getJSONObject("data").getString("cellPhone");
            System.out.println("cellPhone"+string);   //cellPhone15901414066
            User user=new User(1,null,18,"武汉","123",true);
            //fastjson对象转json字符串
            String userString = JSON.toJSONString(user);
            System.out.println(userString); //{"address":"武汉","age":18,"id":1,"isParent":true,"tagId":"123"}
            //fastjson 取json字符串里面的某一个值
            String address = JSON.parseObject(userString).getString("address");
            System.out.println(address);    //武汉
            //fastjson json字符串转回对象
            User user1 = JSON.parseObject(userString, User.class);
            System.out.println(user1); //User(id=1, name=null, age=18, address=武汉, tagId=123, isParent=true)
            //fastjson json字符串转成map
            Map map = JSON.parseObject(userString, Map.class);
            System.out.println(map);  //{address=武汉, isParent=true, tagId=123, id=1, age=18}
            //FastJson  end
    
            //JackJson  start
            System.out.println("JackJson  start");
            User jsckUser=new User(1,null,18,"武汉","123",true);
            ObjectMapper mapper = new ObjectMapper();
            try {
                //jackjson  对象转字符串
                String jsckUer1 = mapper.writeValueAsString(jsckUser);
                System.out.println(jsckUer1); //{"id":1,"name":null,"age":18,"address":"武汉","tagId":"123","isParent":true}
                //jackjson  对象转字节串
                byte[] bytes = mapper.writeValueAsBytes(jsckUser);
                System.out.println(Arrays.toString(bytes));
                //jackjson  字符串转回对象
                User user2 = mapper.readValue(jsckUer1, User.class);
                System.out.println(user2); //User(id=1, name=null, age=18, address=武汉, tagId=123, isParent=true)
                //jackjson  字符串转map
                Map map2 = mapper.readValue(jsckUer1, Map.class);
                System.out.println(map2);  //{id=1, name=null, age=18, address=武汉, tagId=123, isParent=true}
                //jackjson取json字符串的某个值
                JsonNode jsonNode = mapper.readTree(jsckUer1);
                String address2 = jsonNode.get("address").toString();
                System.out.println(address2);  //"武汉"
                String tagId = jsonNode.get("tagId").toString();
                System.out.println(tagId);  //"123"
                //jackJson  集合对象转字符串  字符串转回集合对象
                List<User> userList=new ArrayList<>();
                userList.add(user);
                userList.add(jsckUser);
                String asString = mapper.writeValueAsString(userList);
                List<User> beanList = mapper.readValue(asString, new TypeReference<List<User>>() {});
                System.out.println(beanList); //[User(id=1, name=null, age=18, address=武汉, tagId=123, isParent=true), User(id=1, name=null, age=18, address=武汉, tagId=123, isParent=true)]
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }