Java 在spring集成中Json未转换为对象

我正在吃晚饭

.transform(Transformers.fromJson(SNSMessage.class))

不返回从我的JSON转换的值。JSON输入是

{
    "Type": "Notification",
    "MessageId": "b5c64f3f-59e3-5fce-9ad6-1e98973c9537",
    "TopicArn": "arn:aws:sns:us-east-1:194477963434:local-hera-update",
    "Subject": "com.accuity.hera.model.HeraNotification",
    "Message": "{\"id\":\"65e60559-cab5-4027-88a2-46185fbd50b9\",\"resourceType\":\"listItem\",\"action\":\"I\",\"timeOfAction\":\"2017-05-30T19:48:46Z\",\"source\":\"gwl\"}",
    "Timestamp": "2017-05-30T19:48:47.593Z",
    "SignatureVersion": "1",
    "Signature": "Xz0qg0byLMA1fwIRbi7aWcEzhtcLBOmzyUluL1W5URu4WaiEO3G\/+hPSpsFXGxcSYNYRgpKhL9QAP2qLkuMlSEMqiEOHaSr88UaB8QRV2lUEjdBAWpuFYVBPdb+jpo6n3m89vVHoYfFWk8yBkc0zuoRl4OYcUXfTZiWWQkkrT8r9OzWU8LxQwgf0jgr1xEoqbl7uMHIp7nHp3cKstQ0mbK6yxMQ8faxfDm+IwH3k8BBH2\/CXmRg9WME6JK77jvagMUHNhUahWKIjm4iz+TCQCdnmHQR21hmgxlkhdrSxZ1FBbk6BjxfX7gorEwwfY1gYNoZCXxsN63+4vSiFMlOAAQ==",
    "SigningCertURL": "https:\/\/sns.us-east-1.amazonaws.com\/SimpleNotificationService-b95095beb82e8f6a046b3aafc7f4149a.pem",
    "UnsubscribeURL": "https:\/\/sns.us-east-1.amazonaws.com\/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:us-east-1:194477963434:local-hera-update:7de3da56-9e6c-43ca-9abc-d46fff379380"
}

类别定义为：

public class SNSMessage {
    private String Type;
    private String MessageId;
    private String TopicArn;
    private String Subject;
    private String Message;
    private String Timestamp;
    private String SignatureVersion;
    private String Signature;
    private String SigningCertURL;
    private String UnsubscribeURL;
}

---

你知道为什么SNSMessage的所有字段都设置为null吗？

问题是，你的json属性使用的大写字母与pojo属性不同

这意味着您将

Type

作为json属性，并为getter检测到

Type

您需要像这样使用

@JsonProperty

注释：

@JsonProperty("Type") 
private String type;
...
// getters / setters for type

---

顺便说一句，如果您不想遵循java命名标准并拥有

Type

以及pojo属性，那么只需将

@JsonProperty

添加到属性中，而不使用args

就可以使用jackson的ObjectMapper吗？可能与Federico Piazza重复--jackson的ObjectMapper是底层实现，Ivan Pronin——没有回溯发生，也不是你提到的复杂结构问题。@DonHosek，那么你就不能

ObjectMapper mapper=new ObjectMapper（）；readValue（json、SNSMessage.class）？