hibernate-validator: better support for custom ConstraintValidatorFactory

- simplify custom ConstraintValidatorFactory based on DI as well as manually created factories
- integrates Validator factory into hibernate

- fix #3595

Author: jknack

docs/asciidoc/modules/hibernate-validator.adoc

@@ -17,7 +17,10 @@ Bean validation via https://hibernate.org/validator/[Hibernate Validator].
 import io.jooby.hibernate.validator.HibernateValidatorModule;
 
 {
-  install(new HibernateValidatorModule());
+  install(new HibernateValidatorModule());  <1>
+  
+  // Optional
+  install(new HibernateModule());           <2>
 }
 ----
 
@@ -27,10 +30,17 @@ import io.jooby.hibernate.validator.HibernateValidatorModule;
 import io.jooby.hibernate.validator.HibernateValidatorModule
 
 {
-  install(HibernateValidatorModule())
+  install(HibernateValidatorModule())       <1>
+
+  // Optional
+  install(new HibernateModule())            <2>
 }
 ----
 
+<1> Install Hibernate Validator
+<2> HibernateModule must be installed after HibernateValidatorModule. This step is optional, but
+required if you choose Hibernate as persistence provider. 
+
 3) Usage in MVC routes
 
 .Java
@@ -281,72 +291,25 @@ As you know, `Hibernate Validator` allows you to build fully custom `ConstraintV
 In some scenarios, you may need access not only to the bean but also to services, repositories, or other resources
 to perform more complex validations required by business rules.
 
-In this case you need to implement a custom `ConstraintValidatorFactory` that will rely on your DI framework
+In this case you need to implement a custom `ConstraintValidator` that will rely on your DI framework
 instantiating your custom `ConstraintValidator`
 
 1) Implement custom `ConstraintValidatorFactory`:
 
 [source, java]
 ----
-public class MyConstraintValidatorFactory implements ConstraintValidatorFactory {
 
-    private final Function<Class<?>, ?> require;
-    private final ConstraintValidatorFactory defaultFactory;
+@Constraint(validatedBy = MyCustomValidator.class)
+@Target({TYPE, ANNOTATION_TYPE})
+@Retention(RUNTIME)
+public @interface MyCustomAnnotation {
+  String message() default "My custom message";
 
-    public MyConstraintValidatorFactory(Function<Class<?>, ?> require) {
-        this.require = require;
-        try (ValidatorFactory factory = Validation.byDefaultProvider()
-                                          .configure().buildValidatorFactory()) {
-            this.defaultFactory = factory.getConstraintValidatorFactory();
-        }
-    }
+  Class<?>[] groups() default {};
 
-    @Override
-    public <T extends ConstraintValidator<?, ?>> T getInstance(Class<T> key) {
-        if (isBuiltIn(key)) {
-            // use default factory for built-in constraint validators
-            return defaultFactory.getInstance(key);
-        } else {
-            // use DI to instantiate custom constraint validator
-            return (T) require.apply(key);
-        }
-    }
-
-    @Override
-    public void releaseInstance(ConstraintValidator<?, ?> instance) {
-      if(isBuiltIn(instance.getClass())) {
-        defaultFactory.releaseInstance(instance);
-      } else {
-        // No-op: lifecycle usually handled by DI framework
-      }
-    }
-
-    private boolean isBuiltIn(Class<?> key) {
-      return key.getName().startsWith("org.hibernate.validator");
-    }
+  Class<? extends Payload>[] payload() default {};
 }
-----
 
-2) Register your custom `ConstraintValidatorFactory`:
-
-[source, java]
-----
-{
-  install(new HibernateValidatorModule().doWith(cfg -> {
-    cfg.constraintValidatorFactory(new MyConstraintValidatorFactory(this::require));  // <1>
-  }));
-}
-----
-
-<1> This approach using `require` will work with `Guice` or `Avaje`. For `Dagger`, a bit more effort is required,
-but the concept is the same, and the same result can be achieved. Both `Avaje` and `Dagger` require additional
-configuration due to their build-time nature.
-
-
-3) Implement your custom `ConstraintValidator`
-
-[source, java]
-----
 public class MyCustomValidator implements ConstraintValidator<MyCustomAnnotation, Bean> {
 
   // This is the service you want to inject
@@ -365,6 +328,7 @@ public class MyCustomValidator implements ConstraintValidator<MyCustomAnnotation
 }
 ----
 
+
 === Configuration
 Any property defined at `hibernate.validator` will be added automatically:
 

modules/jooby-hibernate-validator/src/main/java/io/jooby/hibernate/validator/HibernateValidatorModule.java

@@ -7,17 +7,18 @@
 
 import static jakarta.validation.Validation.byProvider;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.function.Consumer;
 
 import org.hibernate.validator.HibernateValidator;
 import org.hibernate.validator.HibernateValidatorConfiguration;
 
 import edu.umd.cs.findbugs.annotations.NonNull;
-import io.jooby.Context;
-import io.jooby.Extension;
-import io.jooby.Jooby;
-import io.jooby.StatusCode;
+import io.jooby.*;
+import io.jooby.internal.hibernate.validator.CompositeConstraintValidatorFactory;
 import io.jooby.validation.BeanValidator;
+import jakarta.validation.ConstraintValidatorFactory;
 import jakarta.validation.ConstraintViolationException;
 import jakarta.validation.Validator;
 
@@ -58,6 +59,7 @@ public class HibernateValidatorModule implements Extension {
   private String title = "Validation failed";
   private boolean disableDefaultViolationHandler = false;
   private boolean logException = false;
+  private List<ConstraintValidatorFactory> factories;
 
   /**
    * Setups a configurer callback.
@@ -118,6 +120,21 @@ public HibernateValidatorModule disableViolationHandler() {
     return this;
   }
 
+  /**
+   * Add a custom {@link ConstraintValidatorFactory}. This factory is allowed to returns <code>null
+   * </code> allowing next factory to create an instance (default or one provided by DI).
+   *
+   * @param factory Factory.
+   * @return This module.
+   */
+  public HibernateValidatorModule with(ConstraintValidatorFactory factory) {
+    if (factories == null) {
+      factories = new ArrayList<>();
+    }
+    this.factories.add(factory);
+    return this;
+  }
+
   @Override
   public void install(@NonNull Jooby app) throws Exception {
     var config = app.getConfig();
@@ -132,14 +149,26 @@ public void install(@NonNull Jooby app) throws Exception {
                   hbvConfig.addProperty(CONFIG_ROOT_PATH + "." + k, v.unwrapped().toString()));
     }
 
+    // Set default constraint validator factory.
+    var delegateFactory =
+        new CompositeConstraintValidatorFactory(
+            app, hbvConfig.getDefaultConstraintValidatorFactory());
+    if (this.factories != null) {
+      this.factories.forEach(delegateFactory::add);
+      this.factories.clear();
+    }
+    hbvConfig.constraintValidatorFactory(delegateFactory);
     if (configurer != null) {
       configurer.accept(hbvConfig);
     }
-
+    var services = app.getServices();
     try (var factory = hbvConfig.buildValidatorFactory()) {
-      Validator validator = factory.getValidator();
-      app.getServices().put(Validator.class, validator);
-      app.getServices().put(BeanValidator.class, new BeanValidatorImpl(validator));
+      var validator = factory.getValidator();
+      services.put(Validator.class, validator);
+      services.put(BeanValidator.class, new BeanValidatorImpl(validator));
+      // Allow to access validator factory so hibernate can access later
+      var constraintValidatorFactory = factory.getConstraintValidatorFactory();
+      services.put(ConstraintValidatorFactory.class, constraintValidatorFactory);
 
       if (!disableDefaultViolationHandler) {
         app.error(

modules/jooby-hibernate-validator/src/main/java/io/jooby/internal/hibernate/validator/CompositeConstraintValidatorFactory.java

@@ -0,0 +1,70 @@
+/*
+ * Jooby https://jooby.io
+ * Apache License Version 2.0 https://jooby.io/LICENSE.txt
+ * Copyright 2014 Edgar Espina
+ */
+package io.jooby.internal.hibernate.validator;
+
+import java.util.Deque;
+import java.util.LinkedList;
+
+import org.slf4j.Logger;
+
+import io.jooby.Jooby;
+import jakarta.validation.ConstraintValidator;
+import jakarta.validation.ConstraintValidatorFactory;
+
+public class CompositeConstraintValidatorFactory implements ConstraintValidatorFactory {
+  private final Logger log;
+  private final ConstraintValidatorFactory defaultFactory;
+  private final Deque<ConstraintValidatorFactory> factories = new LinkedList<>();
+
+  public CompositeConstraintValidatorFactory(
+      Jooby registry, ConstraintValidatorFactory defaultFactory) {
+    this.log = registry.getLog();
+    this.defaultFactory = defaultFactory;
+    this.factories.addLast(new RegistryConstraintValidatorFactory(registry));
+  }
+
+  public ConstraintValidatorFactory add(ConstraintValidatorFactory factory) {
+    this.factories.addFirst(factory);
+    return this;
+  }
+
+  @Override
+  public <T extends ConstraintValidator<?, ?>> T getInstance(Class<T> key) {
+    if (isBuiltIn(key)) {
+      // use default factory for built-in constraint validators
+      return defaultFactory.getInstance(key);
+    } else {
+      for (var factory : factories) {
+        var instance = factory.getInstance(key);
+        if (instance != null) {
+          return instance;
+        }
+      }
+      // fallback or fail
+      return defaultFactory.getInstance(key);
+    }
+  }
+
+  @Override
+  public void releaseInstance(ConstraintValidator<?, ?> instance) {
+    if (isBuiltIn(instance.getClass())) {
+      defaultFactory.releaseInstance(instance);
+    } else {
+      if (instance instanceof AutoCloseable closeable) {
+        try {
+          closeable.close();
+        } catch (Exception e) {
+          log.debug("Failed to release constraint", e);
+        }
+      }
+    }
+  }
+
+  private boolean isBuiltIn(Class<?> key) {
+    var name = key.getName();
+    return name.startsWith("org.hibernate.validator") || name.startsWith("jakarta.validation");
+  }
+}

modules/jooby-hibernate-validator/src/main/java/io/jooby/internal/hibernate/validator/RegistryConstraintValidatorFactory.java

@@ -0,0 +1,43 @@
+/*
+ * Jooby https://jooby.io
+ * Apache License Version 2.0 https://jooby.io/LICENSE.txt
+ * Copyright 2014 Edgar Espina
+ */
+package io.jooby.internal.hibernate.validator;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import io.jooby.Registry;
+import io.jooby.exception.RegistryException;
+import jakarta.validation.ConstraintValidator;
+import jakarta.validation.ConstraintValidatorFactory;
+
+public class RegistryConstraintValidatorFactory implements ConstraintValidatorFactory {
+  private final Logger log = LoggerFactory.getLogger(getClass());
+  private final Registry registry;
+
+  public RegistryConstraintValidatorFactory(Registry registry) {
+    this.registry = registry;
+  }
+
+  @Override
+  public <T extends ConstraintValidator<?, ?>> T getInstance(Class<T> key) {
+    try {
+      return registry.require(key);
+    } catch (RegistryException notfound) {
+      return null;
+    }
+  }
+
+  @Override
+  public void releaseInstance(ConstraintValidator<?, ?> instance) {
+    if (instance instanceof AutoCloseable closeable) {
+      try {
+        closeable.close();
+      } catch (Exception e) {
+        log.debug("Failed to release constraint", e);
+      }
+    }
+  }
+}

modules/jooby-hibernate/src/main/java/io/jooby/hibernate/HibernateModule.java

@@ -5,11 +5,7 @@
  */
 package io.jooby.hibernate;
 
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Objects;
-import java.util.Optional;
+import java.util.*;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -127,7 +123,8 @@
  *
  * Transaction and lifecycle of session/entityManager is managed by {@link TransactionalRequest}.
  *
- * <p>Complete documentation is available at: https://jooby.io/modules/hibernate.
+ * <p>Complete documentation is available at: <a
+ * href="https://jooby.io/modules/hibernate">hibernate</a>.
  *
  * @author edgar
  * @since 2.0.0
@@ -159,7 +156,7 @@ public HibernateModule(@NonNull String name, Class<?>... classes) {
    *
    * @param classes Persistent classes.
    */
-  public HibernateModule(Class... classes) {
+  public HibernateModule(Class<?>... classes) {
     this("db", classes);
   }
 
@@ -207,6 +204,17 @@ public HibernateModule(@NonNull String name, List<Class<?>> classes) {
     return this;
   }
 
+  /**
+   * Allow to customize a {@link StatelessSession} before opening it.
+   *
+   * @param sessionProvider Session customizer.
+   * @return This module.
+   */
+  public @NonNull HibernateModule with(@NonNull StatelessSessionProvider sessionProvider) {
+    this.statelessSessionProvider = sessionProvider;
+    return this;
+  }
+
   /**
    * Hook into Hibernate bootstrap components and allow to customize them.
    *
@@ -294,6 +302,19 @@ public void install(@NonNull Jooby application) {
     var sfb = metadata.getSessionFactoryBuilder();
     sfb.applyName(name);
     sfb.applyNameAsJndiName(false);
+    /*
+    Bind Validator instance, so hibernate doesn't create a new factory.
+    Need to scan due hibernate doesn't depend on validation classes
+    */
+    registry.entrySet().stream()
+        .filter(
+            it ->
+                it.getKey()
+                    .getType()
+                    .getName()
+                    .equals("jakarta.validation.ConstraintValidatorFactory"))
+        .findFirst()
+        .ifPresent(it -> sfb.applyValidatorFactory(it.getValue().get()));
 
     configurer.configure(sfb, config);