Route Compile-Time Validation

Micronaut supports validating route arguments at compile time with the validation library. To get started, add the validation dependency to your build:

build.gradle

annotationProcessor "io.micronaut:micronaut-validation" // Java only
kapt "io.micronaut:micronaut-validation" // Kotlin only
implementation "io.micronaut:micronaut-validation"

With the correct dependency on your classpath, route arguments will automatically be checked at compile time. Compilation will fail if any of the following conditions are met:

• The URI template contains a variable that is optional, but the method parameter is not annotated with @Nullable or is an java.util.Optional.

An optional variable is one that allows the route to match a URI even if the value is not present. For example /foo{/bar} matches requests to /foo and /foo/abc. The non-optional variant would be /foo/{bar}. See the URI Path Variables section for more information.

• The URI template contains a variable that is missing from the method arguments.