quarkus-rest-client and quarkus-rest-client-reactive remove trailing slash

[brunobastosg]

Describe the bug

I was upgrading an app from Quarkus 2.9 to Quarkus 3.12 that needs to call a REST endpoint ending with a trailing slash.

In Quarkus 3.12, it doesn't work because the trailing slash is removed, so the API returns an error.

I also tested it in 3.2, 3.8 and 3.11, and the same error occurs.

I found this issue reporting the same problem in Quarkus 2.11, but it says it was fixed in 2.12. But now in Quarkus 3 it is not working again.

Expected behavior

The trailing slash should be kept by the rest client

Actual behavior

Rest client should removes the trailing slash

How to Reproduce?

Unfortunately I don't know any public APIs ending with a trailing slash. But the steps are as follows:

1. Find an API that only works with a trailing slash
2. Use quarkus-rest-client or quarkus-rest-client-reactive to call this API as follows:

Path("/endpoint/ending/with/trailing/slash/")
public interface MyService {
  // the actual methods to call
}

3. The trailing slash will be removed and the API will return an error

Output of uname -a or ver

Linux serpro-1570142 5.19.0-45-generic #46~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Jun 7 15:06:04 UTC 20 x86_64 x86_64 x86_64 GNU/Linux

Output of java -version

openjdk 21.0.3 2024-04-16 LTS OpenJDK Runtime Environment Temurin-21.0.3+9 (build 21.0.3+9-LTS) OpenJDK 64-Bit Server VM Temurin-21.0.3+9 (build 21.0.3+9-LTS, mixed mode, sharing)

Quarkus version or git rev

3.12.1

Build tool (ie. output of mvnw --version or gradlew --version)

Apache Maven 3.9.6 (bc0240f3c744dd6b6ec2920b3cd08dcc295161ae) Maven home: /home/s009414875/.sdkman/candidates/maven/current Java version: 21.0.3, vendor: Eclipse Adoptium, runtime: /home/s009414875/.sdkman/candidates/java/21.0.3-tem Default locale: pt_BR, platform encoding: UTF-8 OS name: "linux", version: "5.19.0-45-generic", arch: "amd64", family: "unix"

Additional information

No response

[quarkus-bot]

/cc @cescoffier (rest-client), @geoand (rest-client)

[geoand]

Any chance you can put together a sample that shows this issue in action?

Thanks

[brunobastosg]

@geoand there you go: https://github.com/brunobastosg/quarkus-rest-client-trailing-slash

[geoand]

Thanks

[brunobastosg]

I just discovered that the error only occurs when the @Path annotation is at the class level. Moving it to the method level resolves the issue.

[geoand]

Thanks for looking into it.

I am actually not going to fix this because it can cause regressions to existing code.
In your case, you can easily overcome the issue by changing:

to:

@Path("/endpoint-with-trailing-slash/")
@RegisterRestClient(configKey = "remote-service")
public interface RemoteService {

    @GET
    String callService();
}

@Path("/endpoint-with-trailing-slash")
@RegisterRestClient(configKey = "remote-service")
public interface RemoteService {

    @GET
    @Path("/")
    String callService();
}

[Sgitario]

@geoand please reconsider your thoughts about this since there are tools that autogenerate the interfaces (openapi generators), so it can't easily change where to put the @Path annotation. Indeed, magically removing the slash is controversial since it's not respecting what the users configure.

Going to history, this was already reported in the past by #27050 and your fix worked for a while, though the class ClientEndpointIndexer is not using the method "handleTrailingSlash" but this.

[geoand]

But wouldn't it be better to fix the generator in that case?

[Sgitario]

But wouldn't it be better to fix the generator in that case?

No, because the server rejects calls without the "/". Technically speaking, the generator works ok, but the rest-client magically drops the "/" without respecting the API contract.

[geoand]

If you want to add some new property that would opt-in to keeping the slash, that's fine with me, but I don't want to change the default behavior.