import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.joyce.jpa.model.ResponseModel;
import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
public class JsonTest {
    static Logger logger = LoggerFactory.getLogger(JsonTest.class);
    @Test
    public void test1() throws JsonProcessingException {
        ResponseModel model = new ResponseModel();
        model.setCode("9999").setError("未知错误");
        String jsonStr = buildJsonStrBy(model);
        logger.info("jsonStr == " + jsonStr);
    String buildJsonStrBy(ResponseModel model) throws JsonProcessingException {
        ObjectMapper mapper = new ObjectMapper();
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
//        mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
        return mapper.writeValueAsString(model);
    ResponseModel deserializingToCouponUserBy(String jsonStr) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
//        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
//        mapper.configure(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL , false);
//        mapper.configure(DeserializationFeature.ACCEPT_EMPTY_ARRAY_AS_NULL_OBJECT , false);
//        mapper.configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT , false);
//        mapper.configure(DeserializationFeature.FAIL_ON_NULL_CREATOR_PROPERTIES , false);
//        mapper.configure(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES , false);
        return mapper.readValue(jsonStr, ResponseModel.class);
@Test
public void test转换成List对象() throws IOException {
    String myUserJsonStr = "[{\"username\":\"zhangsan\",\"age\":20,\"money\":80.0},{\"username\":\"100498008\",\"age\":1,\"money\":10.0}]";
    ObjectMapper mapper = new ObjectMapper();
    mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
// 可以忽略字母大小写，可以解决Json中字段首字母大写不能识别的问题
mapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true);

    CollectionType type = mapper.getTypeFactory().constructCollectionType(List.class, MyUser.class);
    List<MyUser> result = (List)mapper.readValue(myUserJsonStr, type);

}