Unwrap Validator proxy for access to forExecutables (if necessary)

Issue: SPR-15807

Author: jhoeller

spring-context/src/main/java/org/springframework/validation/beanvalidation/MethodValidationInterceptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -81,7 +81,7 @@ public class MethodValidationInterceptor implements MethodInterceptor {
 	}
 
 
-	private final Validator validator;
+	private volatile Validator validator;
 
 
 	/**
@@ -116,7 +116,18 @@ public Object invoke(MethodInvocation invocation) throws Throwable {
 
 		if (forExecutablesMethod != null) {
 			// Standard Bean Validation 1.1 API
-			Object execVal = ReflectionUtils.invokeMethod(forExecutablesMethod, this.validator);
+			Object execVal;
+			try {
+				execVal = ReflectionUtils.invokeMethod(forExecutablesMethod, this.validator);
+			}
+			catch (AbstractMethodError err) {
+				// Probably an adapter (maybe a lazy-init proxy) without BV 1.1 support
+				Validator nativeValidator = this.validator.unwrap(Validator.class);
+				execVal = ReflectionUtils.invokeMethod(forExecutablesMethod, nativeValidator);
+				// If successful, store native Validator for further use
+				this.validator = nativeValidator;
+			}
+
 			Method methodToValidate = invocation.getMethod();
 			Set<ConstraintViolation<?>> result;
 
@@ -137,13 +148,11 @@ public Object invoke(MethodInvocation invocation) throws Throwable {
 			}
 
 			Object returnValue = invocation.proceed();
-
 			result = (Set<ConstraintViolation<?>>) ReflectionUtils.invokeMethod(validateReturnValueMethod,
 					execVal, invocation.getThis(), methodToValidate, returnValue, groups);
 			if (!result.isEmpty()) {
 				throw new ConstraintViolationException(result);
 			}
-
 			return returnValue;
 		}
 

spring-context/src/test/java/org/springframework/validation/beanvalidation/MethodValidationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import javax.validation.Validator;
 import javax.validation.constraints.Max;
 import javax.validation.constraints.NotNull;
 import javax.validation.groups.Default;
@@ -26,6 +27,10 @@
 
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.beans.MutablePropertyValues;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Lazy;
 import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.scheduling.annotation.AsyncAnnotationAdvisor;
@@ -64,7 +69,6 @@ public void testMethodValidationPostProcessor() {
 		ac.close();
 	}
 
-
 	private void doTestProxyValidation(MyValidInterface proxy) {
 		assertNotNull(proxy.myValidMethod("value", 5));
 		try {
@@ -115,6 +119,13 @@ private void doTestProxyValidation(MyValidInterface proxy) {
 		}
 	}
 
+	@Test
+	public void testLazyValidatorForMethodValidation() {
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(
+				LazyMethodValidationConfig.class, CustomValidatorBean.class, MyValidBean.class);
+		ctx.getBean(MyValidInterface.class).myValidMethod("value", 5);
+	}
+
 
 	@MyStereotype
 	public static class MyValidBean implements MyValidInterface<String> {
@@ -165,4 +176,16 @@ public interface OtherGroup {
 	public @interface MyValid {
 	}
 
+
+	@Configuration
+	public static class LazyMethodValidationConfig {
+
+		@Bean
+		public static MethodValidationPostProcessor methodValidationPostProcessor(@Lazy Validator validator) {
+			MethodValidationPostProcessor postProcessor = new MethodValidationPostProcessor();
+			postProcessor.setValidator(validator);
+			return postProcessor;
+		}
+	}
+
 }

spring-orm-hibernate4/src/test/java/org/springframework/validation/hibernatevalidator5/MethodValidationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import javax.validation.Validator;
 import javax.validation.constraints.Max;
 import javax.validation.constraints.NotNull;
 import javax.validation.groups.Default;
@@ -26,11 +27,16 @@
 
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.beans.MutablePropertyValues;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Lazy;
 import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.scheduling.annotation.AsyncAnnotationAdvisor;
 import org.springframework.scheduling.annotation.AsyncAnnotationBeanPostProcessor;
 import org.springframework.validation.annotation.Validated;
+import org.springframework.validation.beanvalidation.CustomValidatorBean;
 import org.springframework.validation.beanvalidation.MethodValidationInterceptor;
 import org.springframework.validation.beanvalidation.MethodValidationPostProcessor;
 
@@ -68,7 +74,6 @@ public void testMethodValidationPostProcessor() {
 		ac.close();
 	}
 
-
 	@SuppressWarnings("unchecked")
 	private void doTestProxyValidation(MyValidInterface proxy) {
 		assertNotNull(proxy.myValidMethod("value", 5));
@@ -120,6 +125,13 @@ private void doTestProxyValidation(MyValidInterface proxy) {
 		}
 	}
 
+	@Test
+	public void testLazyValidatorForMethodValidation() {
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(
+				LazyMethodValidationConfig.class, CustomValidatorBean.class, MyValidBean.class);
+		ctx.getBean(MyValidInterface.class).myValidMethod("value", 5);
+	}
+
 
 	@MyStereotype
 	public static class MyValidBean implements MyValidInterface<String> {
@@ -170,4 +182,16 @@ public interface OtherGroup {
 	public @interface MyValid {
 	}
 
+
+	@Configuration
+	public static class LazyMethodValidationConfig {
+
+		@Bean
+		public static MethodValidationPostProcessor methodValidationPostProcessor(@Lazy Validator validator) {
+			MethodValidationPostProcessor postProcessor = new MethodValidationPostProcessor();
+			postProcessor.setValidator(validator);
+			return postProcessor;
+		}
+	}
+
 }