[Java] Class name / file name casing mismatch for acronyms causes compilation failure

[peombwa]

What are you generating using Kiota, clients or plugins?

API Client/SDK

In what context or format are you using Kiota?

Nuget tool

Client library/SDK language

Java

Describe the bug

The Java code generator produces files where the file name doesn't match the public class name inside, causing compilation to fail with:

error: class X is public, should be declared in a file named X.java

Acronyms (e.g., DLP, BI, MS365D) are likely cased inconsistently between JavaPathSegmenter.NormalizeFileName (which generates the file name) and CodeClassDeclarationWriter (which writes the class declaration). This results in 19 broken files under com.microsoft.graph.beta.models.security.

Expected behavior

The generated file name and public class name always match exactly.

How to reproduce

See microsoftgraph/msgraph-beta-sdk-java#1309 — Gradle Build, API Level Lint, and CodeQL all fail with 19 compileJava errors.

Open API description file

No response

Kiota Version

Microsoft.OpenApi.Kiota v1.31.1

Latest Kiota version known to work for scenario above?(Not required)

No response

Known Workarounds

N/A

Configuration

No response

Debug output

Click to expand log

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### Other information

Fix should normalize acronym casing on `CodeClass.Name` in `JavaRefiner.cs` or `JavaPathSegementer.cs`.

[ramsessanchez]

This turned out to be a GitHub issue where file name casing changes are not detected as modifications.
As a result, when metadata type names changed casing—for example:

• powerBiDlpAuditRecord → powerBIDlpAuditRecord
• mS365DCustomDetectionAuditRecord → ms365dCustomDetectionAuditRecord

the corresponding class names inside the files were updated accordingly. However, Git did not recognize the casing change at the file name level.
This leads to a mismatch during generation:

• Kiota generates /models/security/PowerBIDlpAuditRecord.java
• But after running git add . in the pipeline, the file still appears as /models/security/PowerBiDlpAuditRecord.java in the pull request, because that file was originally committed using the older casing.

The recommended fix is to:

1. Remove the affected files in a commit/PR
2. Regenerate and re-add them in a subsequent run so the correct casing is preserved

This issue is particularly problematic in Java, where the file name must match the class name exactly. In .NET and other languages, similar discrepancies between class names and file names can occur, but they do not cause build or compile failures.
Unfortunately, we cannot enforce casing standards for enums or types in the metadata. One potential alternative would be to normalize casing during generation, but this would introduce breaking changes across multiple v1 API descriptions.

[ramsessanchez]

Closing the pull request as the solution is to instead add a check to our sdk's that prevent case changes such as that from being passed, especially in v1.0 as they present a binary breaking change.

[ramsessanchez]

Keeping issue open in the meantime until this is resolved for Java Beta, and a fix is addressed in either SDK build checks or metadata validation.