Validation is not enforced on HttpExchange interfaces

[GuillaumeVT]

Hello there,

I've been trying to get validation to trigger for outward HTTP calls in the context of @HttpExchange interfaces.

A missing path variable, mandatory request parameter or request body will throw an IllegalArgumentException, but no ConstraintViolationException is thrown when Jakarta constraints are not respected

I found this ticket which seems to indicate that this was raised and implemented in Jan 2023: #29782

However, it seems to not be working, so I've built a small app reproducing the problem attached to this issue.

demo.zip

Thanks in advance

[rstoyanchev]

You need MethodValidationPostProcessor to apply validation via AOP, and the HTTP interface to be a bean:

@Bean
DemoExchange demoExchange() {
    return HttpServiceProxyFactory
            .builderFor(WebClientAdapter.create(WebClient.builder().build()))
            .build()
            .createClient(DemoExchange.class);
}

@Bean
public MethodValidationPostProcessor methodValidationPostProcessor() {
    return new MethodValidationPostProcessor();
}

@Bean
public ApplicationRunner commandLineRunner(DemoExchange demoExchange) {
    return args -> {
        try {
            System.out.println("validation didn't work: " + demoExchange.get(1));
        }
        catch (ConstraintViolationException e) {
            System.out.println("validation worked: " + e.getMessage());
        }
    };
}

[GuillaumeVT]

Thanks @rstoyanchev, It worked with the exchange being a bean.

For the record, I didn't have to add the MethodValidationPostProcessor to make it work