Apache kafka变换对扁平化的有效负载进行去扁平化

我正在尝试为ServiceNow设置Apache Kafka源和接收器连接器。接收器连接器工作得非常完美,我可以使用下面的转换将嵌套的JSON有效负载扁平化为ServiceNow列名。 Reference

"transforms": "FlattenSchema,RenameFields"
"transforms.flatten.type": "org.apache.kafka.connect.transforms.Flatten$Value",
"transforms.flatten.delimiter": "."

基本上,转换会在JSON以下变平

"payload": {
    "prjtId": "123"
}

到

payload.prjtId

现在我正在尝试源连接器,即使用Apache Kafka poll ServiceNow表查找新记录,并将其作为Kafka消息进行流式传输。流消息工作得很好,但我在将表记录转换为预期的嵌套JSON结构时遇到了问题。

我的ServiceNow表有以下列:

messageType
messageName
version
payload.projectId
payload.responseCode

当我使用ServiceNow连接器将此记录作为Kafka消息检索时,我希望它具有以下预期结构,

预期结果:

{

    "messageType": "InventoryRecordUpdate",
    "messageName": "Validated", 
    "version": "v1",
    "payload": {
        "projectId": "123456", 
        "responseCode" : "XXX"
    }
}

但当我尝试以下配置时,我会得到如下所示的result1或result2:

具有

"key.converter": "org.apache.kafka.connect.json.JsonConverter",
"value.converter": "org.apache.kafka.connect.json.JsonConverter",

Result1:它基本上在消息中抛出架构,并将表列封装在“payload”下:

{
    "schema": {
        "type": "struct",
        "fields": [
            {
                "type": "string",
                "optional": true,
                "field": "u_messagetype"
            },
            {
                "type": "string",
                "optional": true,
                "field": "version"
            },
            {
                "type": "string",
                "optional": true,
                "field": "u_messagename"
            },
            {
                "type": "string",
                "optional": true,
                "field": "u_payload_projectid"
            },
            {
                "type": "string",
                "optional": true,
                "field": "u_payload_responsecode"
            }
        ],
        "optional": false
    },
    "payload": {
        "u_messagetype": "InventoryRecordUpdate",
        "u_version": "v2",
        "u_messagename": "Validated",
        "u_payload_projectid": "123456",
        "u_payload_responsecode": "200"
    }
}

通过以下配置,

"key.converter": "org.apache.kafka.connect.json.JsonConverter",
"value.converter": "org.apache.kafka.connect.json.JsonConverter",
"value.converter.schemas.enable": "false",

结果2:它排除了kafka消息体中的发送模式,还删除了名为“payload”的字段,并在没有嵌套的情况下按原样发送字段,如下所示:

{
    "u_messagetype": "InventoryRecordUpdate",
    "u_version": "v2",
    "u_messagename": "Validated",
    "u_payload_projectid": "123456",
    "u_payload_responsecode": "200"
}

我没有找到关于将键“u_payload_projectid”反扁平化为嵌套结构的文档。如果有人能给我指明正确的方向,我将不胜感激。