Everything in CAP / Java
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Domain: Protocols & APIs
Signals
Content: 2
Java: Answers in Java
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Group by: Capability
Domain Protocols & APIsSource capireSource SAP CommunitySource SAP Developer CenterPublished 2021Published 2025Clear all
EntryBySignalsLast activity
Error handlingSAP only
Beginners Guide to Advanced Event MeshBeginners Guide to Advanced Event MeshA scenario-by-scenario walkthrough of Advanced Event Mesh, run through Cloud Integration iFlows: publishing and consuming queue messages, dead message queue setup with retry counts and acknowledgment modes, direct messages, durable topic endpoints and selectors, time-to-live, REST Delivery Points, replay by replication group message ID, parallel consumers with partition keys, and the request-reply pattern. Each scenario is built and verified step by step against a Solace trial account standing in for AEM.PriyankaChak, published 2025-07-24
Effective Axios Error Logging for Robust SAP IntegrationsEffective Axios Error Logging for Robust SAP IntegrationsTwo logged failures printed side by side, and the point is made by looking at them: one tells you what went wrong and one does not. Axios buries the useful part of an HTTP error, and this is what to unwrap before logging it from a CAP service.Sahil2508, published 2025-08-31
SAP Cloud Application Programming Model（CAP）：カスタムロジックの実装 – Part 2SAP Cloud Application Programming Model（CAP）：カスタムロジックの実装 – Part 2A walkthrough of implementing custom logic in a CAP Node.js service for the capire bookshop sample, registering before, on and after handlers around the generated CRUD service for its Books and Orders entities. The before handler validates an incoming order's amount and runs a transactional CQN UPDATE to decrement stock, raising a 400 or 409 through req.error when the amount is invalid or no rows match; an after handler on READ appends a discount note to overstocked books.rasai, published 2021-01-01
GraphQLUnmapped
SAP GraphQL in CAPm (node.js)SAP GraphQL in CAPm (node.js)Adding the GraphQL protocol adapter to a CAP project when it was new — an entity, some data, the feature switched on, and a check that it answers. Short, and it is the earliest account here of CAP speaking something other than OData.enric101, published 2021-11-29
Metadata publishingSAP only
Importing external edmx files to your CAP project using the CDS Graphical ModelerImporting external edmx files to your CAP project using the CDS Graphical ModelerAn EDMX downloaded from the API hub — API_BUSINESS_PARTNER in the example — imported into the CDS model and its entities exposed as projections, done through the graphical modeller rather than cds import. Barely a page long.Xiao-fei_Song, published 2021-05-19
ODataSAP and community
Create a Business Service using CDS, Node.js, SQLite and a OData serviceCreate a Business Service using CDS, Node.js, SQLite and a OData serviceThe stack at its smallest — CDS, Node, SQLite, an OData service — worked through at length. Nothing cloud in it, which is the point: it is the shape of a CAP service before any of the platform arrives.raybanton, published 2021-07-12
Create a Business Service using CDS, Node.js, SQLite and a OData service
Database connectors has changed twice since this was published, most recently in @sap/cds 10.1.0, 2026-09-07. Affects A recipe, Runnable code.
Create CDS Views and expose through OData service in CAPMCreate CDS Views and expose through OData service in CAPMViews defined in CDS and then exposed, which is the whole of what a small CAP service is. Written step by step from cds init onward in Business Application Studio.VenkateshMundru, published 2025-08-11
Custom Functions in OData V4 – SAP Cloud Application Programming ModelCustom Functions in OData V4 – SAP Cloud Application Programming ModelFunctions rather than actions, and the distinction is where it starts: a function must return data and must never change any, so it is the read-only half of custom operations. Then how to declare and implement one on a CAP service.Roopa_N, published 2021-04-28
Custom Functions in OData V4 – SAP Cloud Application Programming Model
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe.
How to Perform Initial Loads from S/4HANA to Advanced Event Mesh with Odata PollHow to Perform Initial Loads from S/4HANA to Advanced Event Mesh with Odata PollWalks through building a Cloud Integration flow that polls the S/4HANA Business Partner OData API on a timer, splits the response into individual records, and publishes each as an event to Advanced Event Mesh through its adapter, with the topic set dynamically from a grouping property. Selects fields and expands associations with $select/$expand against an EDMX from the API Business Hub, and works around the OData V2 adapter's lack of JSON support by falling back to the HTTP adapter with an XML-to-JSON converter. Flags the trade-off: the pattern needs no backend change beyond activating the API, but the polled payload has to stay aligned with whatever event format the ERP pushes on change.AlexPfeil, published 2025-04-04
SAP BTP SDK for iOS & CAP with OData V4 supportSAP BTP SDK for iOS & CAP with OData V4 supportThe iOS SDK gaining OData V4, which until then made connecting a native app to a CAP service awkward — CAP defaults to v4 and the SDK did not speak it. Short, and it marks the date that stopped being a problem.KRiedelsheimer, published 2021-04-21
SAP CAP Adapter to expose OData as custom REST ServiceSAP CAP Adapter to expose OData as custom REST ServiceWalks through consuming an external OData V2 service in a CAP project — cds import converts the Northwind service's EDMX into a CSN and cds.connect.to wires up the remote proxy — then re-exposing it as plain REST with the @protocol:'rest' annotation instead of OData's own envelope. Shows two ways to reshape the response, renaming and dropping fields in a CDS projection or rewriting the returned objects in a custom service handler, and remaps ?pageSize and ?offset onto OData's $top and $skip in that same handler.Former Member, published 2021-09-15
The Complete Guide to Calling Actions in UI5 with Custom CodeThe Complete Guide to Calling Actions in UI5 with Custom CodeWritten because the documentation is thin and the samples sparse, and openly as a note to the author's future self — hand-coding an action call has become a rare task for anyone mostly working in Fiori elements, which is exactly why it is hard to look up when it comes round. Comes with a CAP sample project, so the service half is there too.published 2025-07-21
The End2End Journey: Advocates Service – CAP Service, OData V2/4 & REST in One single ProjectThe End2End Journey: Advocates Service – CAP Service, OData V2/4 & REST in One single ProjectOne CAP service exposing OData V2, OData V4 and REST at the same time, which is unusual enough to be worth the read on its own. Part of an end-to-end series, deployed on Cloud Foundry against HANA Cloud, so the protocol question sits inside a whole application rather than a snippet.KRiedelsheimer, published 2021-05-06
The End2End Journey: Advocates Service – CAP Service, OData V2/4 & REST in One single Project
OData changed in @cap-js-community/odata-v2-adapter 1.10.0, 2023-04-05. Affects A recipe, Runnable code.
OpenAPIUnmapped
Swagger UI | SAP BTP Extension Generators | Hands-on Video TutorialsSwagger UI | SAP BTP Extension Generators | Hands-on Video TutorialsA blog post wrapped around a video playlist from the SAP HANA Academy — Swagger UI for CDS, added to the BTP extension generator series. The written half is an ingredients list and a table of contents; the substance is in the recordings.dvankempen, published 2021-07-09
WebSocketUnmapped
A Practical Real-Time CTI Widget for SAP Sales Cloud V2A Practical Real-Time CTI Widget for SAP Sales Cloud V2A small CAP backend, a WebSocket channel and a UI5 widget in an iframe — enough to get telephony events into Sales Cloud without any custom backend inside the CRM. The smallness is the design.gizemsoylutr, published 2025-11-28
CAP WebSocketsCAP WebSocketsThe early one, from 2021, before an adapter existed to make it ordinary. Read for what the problem looked like when it had to be solved by hand.vvdries, published 2021-01-26
Communicate from a Java Application to ABAP via WebSocket RFC using JCo - Migration GuideCommunicate from a Java Application to ABAP via WebSocket RFC using JCo - Migration GuideWalks a JCo setup from classic CPIC-based RFC to WebSocket RFC: swap the application- or message-server logon properties for jco.client.wshost and jco.client.wsport, and implement DestinationDataProvider's getSSLContext (and, for mTLS, getClientCertificate) since the new connection runs over TLS. It covers building the PKI trust on both sides — a local PKCS12 keystore for the Java side, STRUST's SSL-Server Standard certificate exported and imported for mutual trust on the ABAP side — and notes that on BTP, JCo paired with the Destination service already implements this via the Connectivity service, so the custom SSLContext work can be skipped there.simon_luser, published 2025-01-21
Streaming LLM Output with CAP and WebSocketsStreaming LLM Output with CAP and WebSocketsTokens arriving from the AI SDK's orchestration module, forwarded to the browser as they come rather than after the model finishes. Covers all four pieces — enabling WebSocket support in CAP, a service with actions and events, the streaming itself, and a frontend on the native WebSocket API — which is what makes it the clearest case for why a CAP service would want a socket at all.RobinP, published 2025-11-18
Streaming LLM Output with CAP and WebSockets
LLM integration changed in @cap-js/ai 1.0.0, 2026-04-28. Affects A recipe, Runnable code.