Jackson通过ObjectMapper进行Serialize&Deserialize

Serialized Object to String

	@Test
	public void testSerialized() throws JacksonException {
		//Jackson transfer Object tool
		ObjectMapper objMapper = new ObjectMapper();
		List<Buyer> buyers =  new ArrayList<Buyer>(
		List.of(new Buyer("1","Jeff"),new Buyer("2","Kevin")));
		
		Order order = Order.builder()
									.orderID(1)
									.orderName("TSL")
									.buyer(buyers).
									time(new Date())
									.des("Jackson test")
									.build();
		log.info(objMapper.writeValueAsString(order));
	}

{“time”:“2023/05/06 06:37:32”,“orderName”:“TSL”,
“des”:“Jackson test”,“buy”:[{“id”:“1”,“name”:“Jeff”},
{“id”:“2”,“name”:“Kevin”}]}

Deserialized String to Object

Order orderSerialized = objMapper.readValue(
"{\"time\":\"2023/05/06 06:37:32\",
\"orderName\":\"TSL\",\"des\":\"Jackson test\",
\"buy\":[{\"id\":\"1\",\"name\":\"Jeff\"},
{\"id\":\"2\",\"name\":\"Kevin\"}]}", 
Order.class);

System.out.println(orderSerialized);

Exception

在发序列化时，因缺少构造方法抛出InvalidDefinitionException: no Creator, cannot construct instance of object.

com.fasterxml.jackson.databind.exc.InvalidDefinitionException:
Cannot construct instance of com.book.springtest.Buyer
(no Creators, like default constructor, exist): cannot deserialize
from Object value (no delegate- or property-based Creator)