Karate框架Multipart POST请求自动追加随机串致服务端解码失败

这是Karate框架处理multipart请求的默认行为——自动生成**边界分隔符（boundary）**并添加到请求体中，用来分隔不同的multipart字段。但你的服务端期望接收纯JSON格式，而非标准multipart格式，因此出现了解码错误。

根据需求，有两种处理方式：

方式1：直接发送纯JSON请求（放弃multipart） #

如果服务端实际不需要multipart类型请求，只是误使用了multipart field语法，直接用request关键字设置JSON请求体即可：

* request { operations: '{"query":"mutation PicassoUploadImageRpc($endpointRequestData: EndpointRequestData) { rpcUploadImage( endpointRequestData: $endpointRequestData ) { message data{ allImages } errorDetail{ errorCode errorMessage errorType displayMessage httpStatusCode} } }","variables":{"endpointRequestData":{"rpcPicasso":{"rpcUploadImage":{"modelType":"modelType1","endPointId":59,"files":[{"key":"image","file":12345}],"body" :{"info":{"hotelCode":"1000115873","hotelId":1000115873,"spaceIds":[],"roomIds":[],"sequence":0,"caption":"hello","description":"hello","tags":["abc"],"sourceConfigName":"ingo","vendorImageId":20,"imgSrc":"makemytrip","isOnBoarding":"true"},"imageUrl":""}}}}}' }
When method POST
Then status 200

方式2：手动指定multipart边界（适配服务端） #

如果确实需要发送multipart请求，可手动设置Content-Type头指定自定义边界，确保服务端能识别：

* header Content-Type = "multipart/form-data; boundary=my-custom-boundary"
* multipart field metadata = { operations: '{"query":"mutation PicassoUploadImageRpc($endpointRequestData: EndpointRequestData) { rpcUploadImage( endpointRequestData: $endpointRequestData ) { message data{ allImages } errorDetail{ errorCode errorMessage errorType displayMessage httpStatusCode} } }","variables":{"endpointRequestData":{"rpcPicasso":{"rpcUploadImage":{"modelType":"modelType1","endPointId":59,"files":[{"key":"image","file":12345}],"body" :{"info":{"hotelCode":"1000115873","hotelId":1000115873,"spaceIds":[],"roomIds":[],"sequence":0,"caption":"hello","description":"hello","tags":["abc"],"sourceConfigName":"ingo","vendorImageId":20,"imgSrc":"makemytrip","isOnBoarding":"true"},"imageUrl":""}}}}}' }
When method POST
Then status 200

• Karate的multipart语法自动生成随机边界是HTTP multipart请求的标准规范，用于区分不同表单字段。
• 若服务端不支持multipart格式，必须改用纯JSON请求，避免触发Karate的multipart处理逻辑。

内容的提问来源于stack exchange，提问作者rajeev ranjan