The Designer can handle blob parameters in the body of a REST interface for requests and responses. Blobs may contain different content types. How the content types should be handled can be configured on client and server side by four attributes provided by stereotype REST Operation for REST APIs and REST adapters.
For REST adapters, you can change the options listed below on manually created REST interfaces, or once you have copied your connector definitions to the API folder of your service.
Find below an overview on these attributes and what combinations make sense. Accepted Request Content Type Reject Other Request Content Types Specifies if the REST adapter should reject calls to this endpoint if a request uses a custom content type that does not match the content types listed in Accepted Request Content Type. This can be the case if you set the "Content-Type" header manually. If set to true, and the "Content-Type" header does not match, the adapter does not contact the endpoint at all but rejects calls with an exception ( Define if other content types than defined with Accepted Request Content Type should be rejected with HTTP 415 (Unsupported Media Type). The Runtime reads the related "Content-Type" header and compares it to the content types that are accepted by the service (Accepted Request Content Type). Blob Body Content Type Reject Other Response Content Type Specifies if the REST adapter should reject calls to this endpoint if a request uses a custom content type that does not match the content types listed in Blob Body Content Type. This can be the case if you set the "Accept" header manually. If set to true, and the "Accept" header does not match the content types the service can provide, the adapter does not contact the endpoint at all but rejects calls with an exception (S Define if the service should reject the request with HTTP 406 (Unsupported Media Type) if the client request has accept headers that differ from the ones defined with Blob Body Content Type. The Runtime reads the related "Accept" header and compares it to the content types that can be provided by the service (Blob Body Content Type). The RESTAPI_BlobContent_Example and the RESTAdapter_BlobContent_Example implement a server and a client that exchange blob content (pictures). They have the following blob content setup implemented: The following table shows some example calls and how they would be executed. The following table shows some error cases and their consequences if you do not rely on the automatically generated headers but set your own headers instead. Reject Other Request Content Types = true Direction Attribute Description Adapter Implementation API Implementation Request Defines the content types of the request body. Specify which content type you are sending with your request.
The Runtime generates a matching "Content-Type" header to your request.Define which content types the endpoint accepts. Triggers a content type check by the xUML Runtime. Endpoint '<endpoint URL>' does not declare '<content type>' as accepted content type).Response Defines the content type of the response body. Specify a list of content types you accept as a response.
The Runtime generates a matching "Accept" header to your request.Define which content types the endpoint can return to the client. Triggers a content type check by the xUML Runtime. et "accept" header does not accept any of declared response content types).Examples
Server (RESTAPI_BlobContent_Example) Content Type Settings Description Store a picture POST /picture Accepted Request Content Type image/png;image/jpeg The server can store PNGs and JPGs. Return a picture by id GET /picture/<an id> Blob Body Content Type image/png The server returns PNGs upon request. Client (RESTAdapter_BlobContent_Example) Content Type Settings Send a picture POST /picture Accepted Request Content Type image/png The client sends PNGs. Retrieve a picture GET /picture/<an id> Blob Body Content Type image/png;image/jpeg The client accepts PNGs and JPGs as a response. Good Cases
Client Generated Header Server 1 Store a picture
POST /picture Content-Type: image/png → accepts request ← returns id
HTTP 2012 Retrieve a picture GET /picture/123456 Accept: image/png → accepts request Content-Type: image/png ← returns picture PNG Error Cases
Example Client Custom Header Server 1 Store a picture, wrong content type POST /picture Content-Type: image/svg+xml → accepts request RESTLM/11: Unknown input format (image/svg+xml)2 Store a picture, wrong content type,
server rejects other content types
POST /picture Content-Type: image/svg+xml → ← RESTLM/11 Unknown input format (image/svg+xml)3 Store a picture, wrong content type,
client rejects other content typesPOST /picture
Reject Other Request Content Types = true Content-Type: image/svg+xml ↓ not called at all RESTLM/7: Endpoint '<endpoint URL>' does not declare '<content type>' as accepted content type← 4 Retrieve a picture, wrong content type GET /picture/123456 Accept: image/svg+xml → accepts request RESTLM/10: Cannot generate any of the expected output formats (image/svg+xml)5 Retrieve a picture, wrong content type,
server rejects other content types
GET /picture/123456 Accept: image/svg+xml → Reject Other Response Content Type = true ← RESTLM/10: Cannot generate any of the expected output formats (image/svg+xml
On this Page:
RESTAPI_BlobContent_Example
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Click the icon to download a simple example model that shows the implementation of a REST API that receives and returns Blob content with Scheer PAS Designer. |
RESTAdapter_BlobContent_Example
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Click the icon to download a simple example model that shows how to handle Blob content with a REST call in Scheer PAS Designer. |
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