Add another example for a constraint validator with an injected bean

docs/src/main/asciidoc/validation.adoc

@@ -411,6 +411,44 @@ The scope you choose for your `ConstraintValidator` bean is important:
 - If the `ConstraintValidator` bean implements the `initialize(A constraintAnnotation)` method and depends on the state of the constraint annotation, use the `@Dependent` scope to make sure each annotation context has a separate and properly configured instance of the `ConstraintValidator` bean.
 ====
 
+When injecting beans relying on the runtime configuration, use `@Inject Instance<..>`. Since constraints are initialised
+at build time, it is not possible to completely preconfigure the constraint in the `initialize(..)` method,
+as the runtime information will be missing at that point. The `initialize(..)` method in such scenarios can still be used
+to read the constraint annotation parameters, and perform any work not relying on the runtime configuration.
+Hence, it is recommended that any heavy configuration work happens as part of the injected bean initialisation
+and methods used in the `ConstraintValidator#isValid(..)` implementation are as fast as possible:
+
+[source,java]
+----
+@ApplicationScoped
+public class MyConstraintValidator implements ConstraintValidator<MyConstraint, String> {
+
+    @Inject
+    Instance<MyService> service;
+
+    @Override
+    public boolean isValid(String value, ConstraintValidatorContext context) {
+        if (value == null) {
+            return true;
+        }
+
+        return service.get().validate(value);
+    }
+}
+
+@ApplicationScoped
+public class MyService {
+
+	public MyService(..) {
+		// perform all possible "initialisation" work
+	}
+
+	public boolean validate(String value) {
+		// perform the validation
+	}
+}
+----
+
 === Validation and localization
 
 By default, constraint violation messages will be returned in the build system locale.

integration-tests/hibernate-validator/src/main/java/io/quarkus/it/hibernate/validator/HibernateValidatorTestResource.java

@@ -45,6 +45,7 @@
 import io.quarkus.it.hibernate.validator.groups.MyBeanWithGroups;
 import io.quarkus.it.hibernate.validator.groups.ValidationGroups;
 import io.quarkus.it.hibernate.validator.injection.InjectedConstraintValidatorConstraint;
+import io.quarkus.it.hibernate.validator.injection.InjectedRuntimeConstraintValidatorConstraint;
 import io.quarkus.it.hibernate.validator.injection.MyService;
 import io.quarkus.it.hibernate.validator.orm.TestEntity;
 import io.quarkus.runtime.StartupEvent;
@@ -199,6 +200,12 @@ public String testInjection() {
 
         result.append(formatViolations(validator.validate(new BeanWithInjectedConstraintValidatorConstraint("Invalid value"))));
 
+        result.append(formatViolations(
+                validator.validate(new BeanWithInjectedRuntimeConstraintValidatorConstraint("any text is valid"))));
+
+        result.append(formatViolations(
+                validator.validate(new BeanWithInjectedRuntimeConstraintValidatorConstraint("numbers 12345 don't work"))));
+
         return result.build();
     }
 
@@ -432,6 +439,20 @@ public String getValue() {
         }
     }
 
+    public static class BeanWithInjectedRuntimeConstraintValidatorConstraint {
+
+        @InjectedRuntimeConstraintValidatorConstraint
+        private String value;
+
+        public BeanWithInjectedRuntimeConstraintValidatorConstraint(String value) {
+            this.value = value;
+        }
+
+        public String getValue() {
+            return value;
+        }
+    }
+
     @Target(ElementType.METHOD)
     @Retention(RetentionPolicy.RUNTIME)
     @InterceptorBinding

integration-tests/hibernate-validator/src/main/java/io/quarkus/it/hibernate/validator/injection/InjectedRuntimeConstraintValidator.java

@@ -0,0 +1,24 @@
+package io.quarkus.it.hibernate.validator.injection;
+
+import jakarta.enterprise.context.ApplicationScoped;
+import jakarta.enterprise.inject.Instance;
+import jakarta.inject.Inject;
+import jakarta.validation.ConstraintValidator;
+import jakarta.validation.ConstraintValidatorContext;
+
+@ApplicationScoped
+public class InjectedRuntimeConstraintValidator
+        implements ConstraintValidator<InjectedRuntimeConstraintValidatorConstraint, String> {
+
+    @Inject
+    Instance<MyRuntimeService> service;
+
+    @Override
+    public boolean isValid(String value, ConstraintValidatorContext context) {
+        if (value == null) {
+            return true;
+        }
+
+        return service.get().validate(value);
+    }
+}

integration-tests/hibernate-validator/src/main/java/io/quarkus/it/hibernate/validator/injection/InjectedRuntimeConstraintValidatorConstraint.java

@@ -0,0 +1,21 @@
+package io.quarkus.it.hibernate.validator.injection;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import jakarta.validation.Constraint;
+import jakarta.validation.Payload;
+
+@Target({ ElementType.TYPE_USE, ElementType.FIELD })
+@Retention(RetentionPolicy.RUNTIME)
+@Constraint(validatedBy = { InjectedRuntimeConstraintValidator.class })
+public @interface InjectedRuntimeConstraintValidatorConstraint {
+
+    String message() default "{InjectedRuntimeConstraintValidatorConstraint.message}";
+
+    Class<?>[] groups() default {};
+
+    Class<? extends Payload>[] payload() default {};
+}

integration-tests/hibernate-validator/src/main/java/io/quarkus/it/hibernate/validator/injection/MyRuntimeConfiguration.java

@@ -0,0 +1,9 @@
+package io.quarkus.it.hibernate.validator.injection;
+
+import io.smallrye.config.ConfigMapping;
+
+@ConfigMapping(prefix = "io.quarkus.it.hibernate.validator.injection")
+public interface MyRuntimeConfiguration {
+
+    String pattern();
+}

integration-tests/hibernate-validator/src/main/java/io/quarkus/it/hibernate/validator/injection/MyRuntimeService.java

@@ -0,0 +1,21 @@
+package io.quarkus.it.hibernate.validator.injection;
+
+import java.util.regex.Pattern;
+
+import jakarta.enterprise.context.ApplicationScoped;
+import jakarta.inject.Inject;
+
+@ApplicationScoped
+public class MyRuntimeService {
+
+    private final Pattern pattern;
+
+    @Inject
+    public MyRuntimeService(MyRuntimeConfiguration configuration) {
+        this.pattern = Pattern.compile(configuration.pattern());
+    }
+
+    public boolean validate(String value) {
+        return pattern.matcher(value).matches();
+    }
+}

integration-tests/hibernate-validator/src/main/resources/ValidationMessages.properties

@@ -1,3 +1,4 @@
 MyCustomConstraint.message = invalid MyOtherBean
 InjectedConstraintValidatorConstraint.message = InjectedConstraintValidatorConstraint violation
+InjectedRuntimeConstraintValidatorConstraint.message = InjectedRuntimeConstraintValidatorConstraint violation
 pattern.message=Value is not in line with the pattern

integration-tests/hibernate-validator/src/main/resources/application.properties

@@ -4,3 +4,4 @@ quarkus.datasource.db-kind=h2
 quarkus.datasource.jdbc.url=jdbc:h2:tcp://localhost/mem:test
 quarkus.hibernate-orm.database.generation = drop-and-create
 
+io.quarkus.it.hibernate.validator.injection.pattern=[^0-9]++

integration-tests/hibernate-validator/src/test/java/io/quarkus/it/hibernate/validator/HibernateValidatorFunctionalityTest.java

@@ -325,7 +325,9 @@ public void testNoProduces() {
     public void testInjection() throws Exception {
         StringBuilder expected = new StringBuilder();
         expected.append("passed").append("\n");
-        expected.append("failed: value (InjectedConstraintValidatorConstraint violation)");
+        expected.append("failed: value (InjectedConstraintValidatorConstraint violation)\n");
+        expected.append("passed").append("\n");
+        expected.append("failed: value (InjectedRuntimeConstraintValidatorConstraint violation)");
 
         RestAssured.when()
                 .get("/hibernate-validator/test/injection")