URI Template Matching Regex Min,Max

[RafaelCavazza]

Hi,

Is there a way to define a {min,max} size when using a regex with a path parameter?

Something like:
/bar/{foo:[a-zA-Z0-9]{1,35}}

The '{' and '}' characters are breaking the annotation processor.

[valhallarepo]

Same problem here.

[joao96neto]

same here

[graemerocher]

Not currently, you can apply a @Min @Max constraint on the parameter and handle the error accordingly.

[RafaelCavazza]

Hi @graemerocher ,

We have a specific use case where there are two possible routes diverging only by the parameter regex.

Something like:
/bar/{id1:[a-zA-Z0-9]{10,25}}
/bar/{id2:[a-zA-Z0]{1,10}}

If I understand correctly:
If the regex is valid micronaut can decide the correct route, right?

Is there any other way we can achieve this behavior?

[lancerbh]

+1

[dan1els]

+1 I want the micronaut be able to distinguish the correct root when long id or uuid is in path

[mdeterman]

+1

[mmwinther]

We have this same problem. At the very least the docs should specify that only a subset of regex is supported.

[TatyOko28]

The issue: curly braces { and } are used both for:

• delimiting a path parameter in the URI template ({foo})
• expressing a regex quantifier ({1,35})

Most annotation processors (Spring, JAX-RS, etc.) cannot distinguish between them, causing a parsing error.

Solutions

1. Simple and universal solution: validate inside the controller method

Instead of putting the length constraint in the mapping regex, declare the parameter without a regex and validate the length manually.

Spring MVC:

@GetMapping("/bar/{foo}")
public String getBar(@PathVariable String foo) {
    // Explicit validation
    if (foo == null || !foo.matches("[a-zA-Z0-9]+") || foo.length() < 1 || foo.length() > 35) {
        throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid foo");
    }
    // continue...
    return "ok";
}