1. Prepare to import maven
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.76</version>
</dependency>
2. Convert json object to entity class object
① The json object format is: {"key1": [{object A}, {object B}], "key2": [{object C}, {object D}]}
String aa ="{"data":[{"type":"轿车","id":"001","name":"汽车1号"},{"type":"跑车","id":"002","name":"汽车2号"}],"paList":[]}";
JSONObject dataJson = JSONObject.parseObject(aa);
JSONArray dictData = dataJson.getJSONArray("data");
List<Car> onlineLists = JSONObject.parseArray(dictData.toJSONString(), Car.class);
System.out.println(onlineLists);
//打印结果:[Car(id=1, name=汽车1号, type=轿车), Car(id=2, name=汽车2号, type=跑车)]
② The json object format is: [{object A}, {object B}, {object C}, {object D}]
String cc ="[{"type":"轿车","id":"001","name":"汽车1号"},{"type":"跑
车","id":"002","name":"汽车2号"}]";
JSONArray dataJson3 = JSON.parseArray(cc);
List<Car> onlineLists3 = JSONObject.parseArray(dataJson3.toJSONString(), Car.class);
System.out.println(onlineLists3);
//打印结果:[Car(id=1, name=汽车1号, type=轿车), Car(id=2, name=汽车2号, type=跑车)]
3. Entity class to json
Car car1 = new Car();
car1.setName("汽车3号");
car1.setType("面包车");
System.out.println(car1);
String usersJsonObject = JSON.toJSONString(car1);
System.out.println(usersJsonObject);
//打印结果:{"name":"汽车3号","type":"面包车"}