DATAREST-798 - Fixed invalid implementation of ValidationErrors.

Changed the implementation of ValidationErrors to be based on AbstractBeanPropertyBindingResult to consider the nesting implemented in superclasses and using a PersistentPropertyAccessor to lookup the property values.

ValidatingRepositoryEventListener now uses this implementation if a PersistentEntity can be obtained for the type under consideration, falling back to a DirectFieldBindingResult otherwise.

spring-data-rest-core/src/test/java/org/springframework/data/rest/core/ValidationErrorsUnitTests.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2016 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.rest.core;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+import org.springframework.data.keyvalue.core.mapping.context.KeyValueMappingContext;
+
+/**
+ * Unit tests for {@link ValidationErrors}.
+ * 
+ * @author Oliver Gierke
+ */
+public class ValidationErrorsUnitTests {
+
+	KeyValueMappingContext context = new KeyValueMappingContext();
+
+	/**
+	 * @see DATAREST-798
+	 */
+	@Test
+	public void exposesNestedViolationsCorrectly() {
+
+		ValidationErrors errors = new ValidationErrors(new Foo(), context.getPersistentEntity(Foo.class));
+
+		errors.pushNestedPath("bars[0]");
+		errors.rejectValue("field", "asdf");
+		errors.popNestedPath();
+
+		assertThat(errors.getFieldError().getField(), is("bars[0].field"));
+	}
+
+	static class Foo {
+		List<Bar> bars = new ArrayList<Bar>();
+	}
+
+	static class Bar {
+		String field;
+	}
+}

spring-data-rest-core/src/test/java/org/springframework/data/rest/core/context/ValidatorIntegrationTests.java

@@ -23,6 +23,7 @@ import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
+import org.springframework.data.keyvalue.core.mapping.context.KeyValueMappingContext;
 import org.springframework.data.mapping.context.PersistentEntities;
 import org.springframework.data.rest.core.RepositoryConstraintViolationException;
 import org.springframework.data.rest.core.RepositoryTestsConfig;
@@ -59,10 +60,13 @@ public class ValidatorIntegrationTests {
 	}
 
 	@Autowired ConfigurableApplicationContext context;
+	@Autowired KeyValueMappingContext mappingContext;
 
 	@Test(expected = RepositoryConstraintViolationException.class)
 	public void shouldValidateLastName() throws Exception {
 
+		mappingContext.getPersistentEntity(Person.class);
+
 		// Empty name should be rejected by PersonNameValidator
 		context.publishEvent(new BeforeSaveEvent(new Person("Dave", "")));
 	}