com.fasterxml.jackson包序列化json对象和反序列化
需要序列化的类需实现接口:
public class ResponseModel implements Serializable {
序列化和反序列化代码例子:
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);
}
}
end.