我正在生成json消息，并尝试使其符合Avro标准。这是我要发送的消息的示例，但是我收到以下错误，我认为这是由于架构不匹配数据，但可能是错误的，我将KafkaAvroSerializer.class.getName（）用于值序列化程序

Point[] hull; Point[][] contours; for (int i = 0; i < contours.Length; i++) { hull = Cv2.ConvexHull(contours[i],false); defects = Cv2.ConvexityDefects(contours[i],hull); Cv2.DrawContours(frame,new Point[][] { hull },(int)largestContour,new OpenCvSharp.Scalar(0,255),2); }

nested exception is org.apache.kafka.common.errors.SerializationException: Error serializing Avro message; nested exception is org.apache.kafka.common.errors.SerializationException: Error serializing Avro message

Caused by: java.lang.NullPointerException: null of string of com.lm.gde.eventing.avro.CoveragesPreviousPolicy of com.lm.gde.eventing.avro.VehiclesPreviousPolicy of array of com.lm.gde.eventing.avro.previous_policy of com.lm.gde.eventing.avro.PolicyAvro of com.lm.gde.eventing.avro.EnrichedPolicyEventAvro

这是我编写的架构

{
    "eventType": "policy.PolicyTxIssueEvent","correlationId": "XXXXXX","timestamp": 1572532310225,"policy": {
        "policyNumber": "XXXXXX","policyId": "XXXXXX","customerNumber": "XXXXXX","effectiveDate": "2019-10-26T00:00:00+01:00","expirationDate": "2020-10-25T23:59:00Z","transactionEffectiveDate": "2019-10-31T00:00:00Z","revisionNumber": "2","policyStatusCd": "issued","previousPolicyVersionId": "XXXXXX","transactionTypeCd": "endorsement","vehicles": [{
            "registrationNo": "XXXXXX","make": "XXXXXX","model": "XXXXXX","coverages": {
                "roadAssistanceCoverLevelCd": "Medium"
            }
        }],"customer": {
            "extensionFields": {
                "nif": "XXXXXX"
            },"individualDetails": {
                "firstName": "XXXXXX","lastName": "XXXXXX"
            },"phones": [{
                "phoneNumber": "XXXXXX"
            }],"addresses": [{
                "addressLine1": "XXXXXX","addressLine2": "","addressLine3": "","city": "XXXXXX","postalCode": "XXXXXX"
            }]
        },"previous_policy": {
            "vehicles": [{
                "registrationNo": "XXXXXX","coverages": {
                    "roadAssistanceCoverLevelCd": null
                }
            }],"policyNumber": "XXXXXX","transactionEffectiveDate": "2019-10-26T00:00:00+01:00","transactionTypeCd": "policy","revisionNumber": "1","previousPolicyVersionId": null
        }
    }
}