我试图使用汇合的过滤器smt与debezium的例子展开smt。
我将以下配置添加到源连接器（debezium mysql）配置中：

"transforms": "route,csFilter",
    ...
    ...
    "transforms.csFilter.type": "io.confluent.connect.transforms.Filter$Value",
    "transforms.csFilter.filter.condition": "$.payload.after.source == 2",
    "transforms.csFilter.filter.type": "exclude",
    "transforms.csFilter.missing.or.null.behavior": "fail"

因为这个过滤器smt是由confluent提供的，所以我下载了jar文件并将（connect transforms、connect utils、json path）jar文件复制到 path-to-kafka/connect/debezium-connector-mysql 目录。
当我试图注册debezium mysql源代码连接器时，

curl -i -X POST -H "Accept:application/json" -H "Content-Type:application/json" 
localhost:8083/connectors/ -d @source_connector_config.json

我有个错误：

{"error_code":400,
"message":"Connector configuration is invalid and contains the following 1 error(s):\n
Invalid value $.payload.after.source == 2 for configuration filter.condition: Invalid json path defined. 
Please refer to https://github.com/json-path/JsonPath README for correct use of json path.\n
You can also find the above list of errors at the endpoint `/{connectorType}/config/validate`"}

我用本指南中提供的示例检查了json路径表达式。好像没事。
你能给我指一下正确的方向吗？我错过了什么？谢谢。