Json序列化与反序列化

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Goods {
    private Long skuId;
    private String title;
    private Long price;

    @JsonFormat(pattern = "yyyy-MM-dd hh:mm")
    private Date createTime;
}

ObjectMapper objectMapper = new ObjectMapper();

// 序列/反序列一个普通pojo对象
@Test
public void testObject() throws JsonProcessingException {
    Goods goods = new Goods(1L, "一加6", 11110L, new Date());

    // 序列化
    String goodsJson = objectMapper.writeValueAsString(goods);
    System.out.println("goodsJson = " + goodsJson);

    // 反序列化
    Goods g = objectMapper.readValue(goodsJson, Goods.class);
    System.out.println("g = " + g);
}


// 序列/反序列一个集合
@Test
public void testList() throws JsonProcessingException {
    ArrayList<Goods> goodsList = new ArrayList<>();
    goodsList.add(new Goods(1L, "一加6", 11110L, new Date()));
    goodsList.add(new Goods(2L, "一加7", 2222220L, new Date()));

    // 序列化
    String json = objectMapper.writeValueAsString(goodsList);
    System.out.println("json = " + json);

    // 反序列化
    List list = objectMapper.readValue(json, new TypeReference<List<Goods>>() {
    });
    System.out.println("list = " + list);
}

// 序列/反序列一个map
@Test
public void testMap() throws JsonProcessingException {
    HashMap<Integer, Goods> map = new HashMap<>();
    map.put(1, new Goods(1L, "一加6", 11110L, new Date()));
    map.put(2, new Goods(2L, "一加7", 2222220L, new Date()));

    // 序列化
    String json = objectMapper.writeValueAsString(map);
    System.out.println("json = " + json);

    // 反序列化
    Map<Integer, Goods> goodsMap = objectMapper.readValue(json, new TypeReference<Map<Integer, Goods>>() {
    });
    System.out.println("goodsMap = " + goodsMap);
}