json
test
ObjectMapper mapper = new ObjectMapper();
String response=json对象
// 对象
User user = mapper.readValue(response, User.class);
// json 简单list
List<User> list = mapper.readValue(response, mapper.getTypeFactory().constructCollectionType(List.class, User.class));
// json 复杂list
List<User> list2 = mapper.readValue(response, new TypeReference<List<User>>() {
});