关于java:对象与json转换

/**
 * 测试简略对象的转化
 */
@Test
public void test01() throws JsonProcessingException {ObjectMapper objectMapper = new ObjectMapper();
    ItemDesc itemDesc = new ItemDesc();
    itemDesc.setItemId(100L).setItemDesc("商品详情信息")
            .setCreated(new Date()).setUpdated(new Date());
    // 对象转化为 json
    String json = objectMapper.writeValueAsString(itemDesc);
    System.out.println(json);

    //json 转化为对象
    ItemDesc itemDesc2 = objectMapper.readValue(json, ItemDesc.class);
    System.out.println(itemDesc2.getItemDesc());
}

/**
 * 测试汇合对象的转化
 */
@Test
public void test02() throws JsonProcessingException {ObjectMapper objectMapper = new ObjectMapper();
    ItemDesc itemDesc = new ItemDesc();
    itemDesc.setItemId(100L).setItemDesc("商品详情信息 1")
            .setCreated(new Date()).setUpdated(new Date());
    ItemDesc itemDesc2 = new ItemDesc();
    itemDesc2.setItemId(100L).setItemDesc("商品详情信息 2")
            .setCreated(new Date()).setUpdated(new Date());
    List<ItemDesc> lists = new ArrayList<>();
    lists.add(itemDesc);
    lists.add(itemDesc2);
    //[{key:value},{}]
    String json = objectMapper.writeValueAsString(lists);
    System.out.println(json);

    // 将 json 串转化为对象
    List<ItemDesc> list2 = objectMapper.readValue(json, lists.getClass());
    System.out.println(list2);
}