JSON解析错误：无法构造`com.dto.iddto`的实例（尽管至少存在一个创建者）

Question

我正在使用以下DTO：

public class IdDTO extends BasicResponseDTO {
    private long id;

    public IdDTO(long id) {
        this.id = id;
    }

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

}

和

public class BasicResponseDTO implements Serializable {

    private String errorCode;

    public BasicResponseDTO() {
        this.setErrorCode(null);
    }

    public String getErrorCode() {
        return errorCode;
    }

    public void setErrorCode(String errorCode) {
        this.errorCode = errorCode;
    }

}

我调用了一个REST web服务，并从Postman那里看到我（正确地）收到了以下响应：

{
    "errorCode": null,
    "id": 3534016
}

class org.springframework.web.client.RestClientException/Error while extracting response for type [class com.dto.IdDTO] and content type [application/json;charset=UTF-8]; nested exception is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot construct instance of `com.dto.IdDTO` (although at least one Creator exists): cannot deserialize from Object value (no delegate- or property-based Creator); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.dto.IdDTO` (although at least one Creator exists): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: (PushbackInputStream); line: 1, column: 2]

附言。1）我还有其他扩展BasicResponseDTO的DTO，反序列化对它们很有效。

附言。2）在服务器和客户端上，类的定义是相同的。

Answer 1

IDDTO上没有默认构造函数。只有一个带ID：

public IdDTO(long id) {
    this.id = id;
}

你必须加上一个：

public IdDTO() {
}

这是JSON反序列化从类构造对象所需要的