Document JTI claim generation

src/main/docs/guide/authenticationStrategies/jwt/claimsGeneration.adoc

@@ -1,3 +1,10 @@
 If the built-in
 link:{api}/io/micronaut/security/token/jwt/generator/claims/JWTClaimsSetGenerator.html[JWTClaimsSetGenerator], does not
-fulfil your needs you can provide your own https://micronaut-projects.github.io/micronaut-core/latest/guide/#replaces[replacement] of link:{api}/io/micronaut/security/token/jwt/generator/claims/ClaimsGenerator.html[ClaimsGenerator].
+fulfil your needs you can provide your own https://micronaut-projects.github.io/micronaut-core/latest/guide/#replaces[replacement] of api:io.micronaut.security.token.claims.ClaimsGenerator[].
+
+The built-in `JWTClaimsSetGenerator` adds the JWT ID (`jti`) claim when the application provides a bean of type api:io.micronaut.security.token.claims.JtiGenerator[].
+The value returned by `generateJtiClaim()` is used as the case-sensitive unique identifier for the JWT:
+
+snippet::io.micronaut.docs.claimsjti.CustomJtiGenerator[tags="clazz"]
+
+If you are migrating from the old `io.micronaut.security.token.jwt.generator.claims.JwtIdGenerator`, use `io.micronaut.security.token.claims.JtiGenerator` instead.

test-suite/src/test/java/io/micronaut/docs/claimsjti/CustomJtiGenerator.java

@@ -0,0 +1,19 @@
+package io.micronaut.docs.claimsjti;
+
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.security.token.claims.JtiGenerator;
+import jakarta.inject.Singleton;
+
+import java.util.UUID;
+
+@Requires(property = "spec.name", value = "claims-generation-docs")
+//tag::clazz[]
+@Singleton
+class CustomJtiGenerator implements JtiGenerator {
+
+    @Override
+    public String generateJtiClaim() {
+        return UUID.randomUUID().toString();
+    }
+}
+//end::clazz[]