Expose Validator bean

This commit improves ValidationAutoConfiguration so that a `Validator`
bean is exposed if JSR 303 is available. This has the side effect of
automatically enable Spring Data Couchbase's entity validation rather
than requiring to expose a `Validator` bean.

Closes gh-5178

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/couchbase/CouchbaseDataAutoConfiguration.java

@@ -22,9 +22,10 @@ import com.couchbase.client.java.Bucket;
 
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnSingleCandidate;
 import org.springframework.boot.autoconfigure.couchbase.CouchbaseAutoConfiguration;
+import org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -41,7 +42,8 @@ import org.springframework.data.couchbase.repository.CouchbaseRepository;
  */
 @Configuration
 @ConditionalOnClass({ Bucket.class, CouchbaseRepository.class })
-@AutoConfigureAfter(CouchbaseAutoConfiguration.class)
+@AutoConfigureAfter({ CouchbaseAutoConfiguration.class,
+		ValidationAutoConfiguration.class })
 @EnableConfigurationProperties(CouchbaseDataProperties.class)
 @Import({ CouchbaseConfigurerAdapterConfiguration.class,
 		SpringBootCouchbaseDataConfiguration.class })
@@ -52,7 +54,7 @@ public class CouchbaseDataAutoConfiguration {
 	public static class ValidationConfiguration {
 
 		@Bean
-		@ConditionalOnBean(Validator.class)
+		@ConditionalOnSingleCandidate(Validator.class)
 		public ValidatingCouchbaseEventListener validationEventListener(
 				Validator validator) {
 			return new ValidatingCouchbaseEventListener(validator);

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/validation/ValidationAutoConfiguration.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.validation;
 
 import javax.validation.Validation;
+import javax.validation.Validator;
 import javax.validation.executable.ExecutableValidator;
 
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
@@ -32,6 +33,7 @@ import org.springframework.context.annotation.Conditional;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
 import org.springframework.core.type.AnnotatedTypeMetadata;
+import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
 import org.springframework.validation.beanvalidation.MethodValidationPostProcessor;
 
 /**
@@ -42,14 +44,22 @@ import org.springframework.validation.beanvalidation.MethodValidationPostProcess
  * @since 1.5.0
  */
 @ConditionalOnClass(ExecutableValidator.class)
+@ConditionalOnResource(resources = "classpath:META-INF/services/javax.validation.spi.ValidationProvider")
+@Conditional(ValidationAutoConfiguration.OnValidatorAvailableCondition.class)
 public class ValidationAutoConfiguration {
 
 	@Bean
-	@ConditionalOnResource(resources = "classpath:META-INF/services/javax.validation.spi.ValidationProvider")
-	@Conditional(OnValidatorAvailableCondition.class)
 	@ConditionalOnMissingBean
-	public MethodValidationPostProcessor methodValidationPostProcessor() {
-		return new MethodValidationPostProcessor();
+	public Validator validator() {
+		return new LocalValidatorFactoryBean();
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public MethodValidationPostProcessor methodValidationPostProcessor(Validator validator) {
+		MethodValidationPostProcessor processor = new MethodValidationPostProcessor();
+		processor.setValidator(validator);
+		return processor;
 	}
 
 	@Order(Ordered.LOWEST_PRECEDENCE)

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/couchbase/CouchbaseDataAutoConfigurationTests.java

@@ -18,20 +18,17 @@ package org.springframework.boot.autoconfigure.data.couchbase;
 
 import java.util.Set;
 
-import javax.validation.Validator;
-
 import org.junit.After;
 import org.junit.Test;
 
-import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
 import org.springframework.boot.autoconfigure.couchbase.CouchbaseAutoConfiguration;
 import org.springframework.boot.autoconfigure.couchbase.CouchbaseTestConfigurer;
 import org.springframework.boot.autoconfigure.data.couchbase.city.City;
 import org.springframework.boot.autoconfigure.domain.EntityScan;
+import org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration;
 import org.springframework.boot.test.util.EnvironmentTestUtils;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
-import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 import org.springframework.data.couchbase.config.AbstractCouchbaseDataConfiguration;
@@ -44,7 +41,6 @@ import org.springframework.data.couchbase.repository.support.IndexManager;
 import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link CouchbaseDataAutoConfiguration}.
@@ -79,11 +75,9 @@ public class CouchbaseDataAutoConfigurationTests {
 
 	@Test
 	public void validatorIsPresent() {
-		load(ValidatorConfiguration.class);
-		ValidatingCouchbaseEventListener listener = this.context
-				.getBean(ValidatingCouchbaseEventListener.class);
-		assertThat(new DirectFieldAccessor(listener).getPropertyValue("validator"))
-				.isEqualTo(this.context.getBean(Validator.class));
+		load(CouchbaseTestConfigurer.class);
+		assertThat(this.context.getBeansOfType(ValidatingCouchbaseEventListener.class))
+				.hasSize(1);
 	}
 
 	@Test
@@ -132,22 +126,12 @@ public class CouchbaseDataAutoConfigurationTests {
 			context.register(config);
 		}
 		context.register(PropertyPlaceholderAutoConfiguration.class,
-				CouchbaseAutoConfiguration.class, CouchbaseDataAutoConfiguration.class);
+				ValidationAutoConfiguration.class, CouchbaseAutoConfiguration.class,
+				CouchbaseDataAutoConfiguration.class);
 		context.refresh();
 		this.context = context;
 	}
 
-	@Configuration
-	@Import(CouchbaseTestConfigurer.class)
-	static class ValidatorConfiguration {
-
-		@Bean
-		public Validator myValidator() {
-			return mock(Validator.class);
-		}
-
-	}
-
 	@Configuration
 	static class CustomCouchbaseConfiguration extends AbstractCouchbaseDataConfiguration {
 

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/validation/ValidationAutoConfigurationTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.validation;
 
 import javax.validation.ConstraintViolationException;
+import javax.validation.Validator;
 import javax.validation.constraints.Size;
 
 import org.junit.After;
@@ -24,6 +25,7 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -54,6 +56,7 @@ public class ValidationAutoConfigurationTests {
 	@Test
 	public void validationIsEnabled() {
 		load(SampleService.class);
+		assertThat(this.context.getBeansOfType(Validator.class)).hasSize(1);
 		SampleService service = this.context.getBean(SampleService.class);
 		service.doSomething("Valid");
 		this.thrown.expect(ConstraintViolationException.class);
@@ -63,10 +66,15 @@ public class ValidationAutoConfigurationTests {
 	@Test
 	public void userDefinedMethodValidationPostProcessorTakesPrecedence() {
 		load(SampleConfiguration.class);
+		assertThat(this.context.getBeansOfType(Validator.class)).hasSize(1);
+		Object userMethodValidationPostProcessor =
+				this.context.getBean("testMethodValidationPostProcessor");
 		assertThat(this.context.getBean(MethodValidationPostProcessor.class))
-				.isSameAs(this.context.getBean("testMethodValidationPostProcessor"));
+				.isSameAs(userMethodValidationPostProcessor);
 		assertThat(this.context.getBeansOfType(MethodValidationPostProcessor.class))
 				.hasSize(1);
+		assertThat(this.context.getBean(Validator.class)).isNotSameAs(
+				new DirectFieldAccessor(userMethodValidationPostProcessor).getPropertyValue("validator"));
 	}
 
 	public void load(Class<?> config) {

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/validation/ValidationAutoConfigurationWithHibernateValidatorMissingElImplTests.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.validation;
 
+import javax.validation.Validator;
+
 import org.junit.After;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -50,6 +52,7 @@ public class ValidationAutoConfigurationWithHibernateValidatorMissingElImplTests
 	public void validationIsDisabled() {
 		this.context = new AnnotationConfigApplicationContext(
 				ValidationAutoConfiguration.class);
+		assertThat(this.context.getBeansOfType(Validator.class)).isEmpty();
 		assertThat(this.context.getBeansOfType(MethodValidationPostProcessor.class))
 				.isEmpty();
 	}

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/validation/ValidationAutoConfigurationWithoutValidatorTests.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.validation;
 
+import javax.validation.Validator;
+
 import org.junit.After;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -49,6 +51,7 @@ public class ValidationAutoConfigurationWithoutValidatorTests {
 	public void validationIsDisabled() {
 		this.context = new AnnotationConfigApplicationContext(
 				ValidationAutoConfiguration.class);
+		assertThat(this.context.getBeansOfType(Validator.class)).isEmpty();
 		assertThat(this.context.getBeansOfType(MethodValidationPostProcessor.class))
 				.isEmpty();
 	}