博客

今天在写springboot单元测试的时候，序列化对象时出现一个错误：

Cannot construct instance of `com.*.GeneralResponse` (although at least one Creator exists): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: (String)"{"transaction_id":"123"}"; line: 1, column: 2]
com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.*.GeneralResponse` (although at least one Creator exists): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: (String)"{"transaction_id":"123"}"; line: 1, column: 2]

需要序列化的json串为：

{"transaction_id":"123"}

对象为：

@Getter
@Setter
@AllArgsConstructor
public class GeneralResponse {
    private String transactionId;
}

错误的原因是没有无参构造函数，json在转对象反序列化的时候，需要先初始化对象，默认调用无参构造函数，再赋值，在使用@Builder注解时必须搭配@AllArgsConstructor 和@NoArgsConstructor同时使用。