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/main/java/org/springframework/data/rest/core/ValidationErrors.java

@@ -1,88 +1,100 @@
+/*
+ * Copyright 2012-2016 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.springframework.util.ReflectionUtils.*;
-
-import java.lang.reflect.Field;
-import java.lang.reflect.Method;
-import java.util.ArrayList;
-import java.util.List;
-
+import org.springframework.beans.BeansException;
+import org.springframework.beans.ConfigurablePropertyAccessor;
+import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
-import org.springframework.validation.AbstractErrors;
+import org.springframework.data.mapping.PersistentPropertyAccessor;
+import org.springframework.util.Assert;
+import org.springframework.validation.AbstractPropertyBindingResult;
 import org.springframework.validation.Errors;
-import org.springframework.validation.FieldError;
-import org.springframework.validation.ObjectError;
 
 /**
- * An {@link Errors} implementation for use in the events mechanism of Spring Data REST.
+ * An {@link Errors} implementation for use in the events mechanism of Spring Data REST. Customizes actual field lookup
+ * by using a {@link PersistentPropertyAccessor} for actual value lookups.
  * 
  * @author Jon Brisbin
+ * @author Oliver Gierke
  */
-public class ValidationErrors extends AbstractErrors {
+public class ValidationErrors extends AbstractPropertyBindingResult {
 
 	private static final long serialVersionUID = 8141826537389141361L;
 
-	private String name;
-	private Object entity;
-	private PersistentEntity<?, ?> persistentEntity;
-	private List<ObjectError> globalErrors = new ArrayList<ObjectError>();
-	private List<FieldError> fieldErrors = new ArrayList<FieldError>();
+	private final PersistentPropertyAccessor accessor;
+	private PersistentEntity<?, ?> entity;
+
+	/**
+	 * Creates a new {@link ValidationErrors} instance for the given source object and {@link PersistentEntity}.
+	 * 
+	 * @param source the source object to gather validation errors on, must not be {@literal null}.
+	 * @param entity the {@link PersistentEntity} for the given source instance, must not be {@literal null}.
+	 */
+	public ValidationErrors(Object source, PersistentEntity<?, ?> entity) {
+
+		super(source.getClass().getSimpleName());
+
+		Assert.notNull(source, "Entity must not be null!");
+		Assert.notNull(entity, "PersistentEntity must not be null!");
+		Assert.isTrue(entity.getType().isInstance(source),
+				"Given source object is not of type of the given PersistentEntity");
 
-	public ValidationErrors(String name, Object entity, PersistentEntity<?, ?> persistentEntity) {
-		this.name = name;
 		this.entity = entity;
-		this.persistentEntity = persistentEntity;
+		this.accessor = entity.getPropertyAccessor(source);
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.validation.AbstractPropertyBindingResult#getPropertyAccessor()
+	 */
 	@Override
-	public String getObjectName() {
-		return name;
-	}
-
-	@Override
-	public void reject(String errorCode, Object[] errorArgs, String defaultMessage) {
-		globalErrors.add(new ObjectError(name, new String[] { errorCode }, errorArgs, defaultMessage));
-	}
-
-	@Override
-	public void rejectValue(String field, String errorCode, Object[] errorArgs, String defaultMessage) {
-		fieldErrors.add(new FieldError(name, field, getFieldValue(field), true, new String[] { errorCode }, errorArgs,
-				defaultMessage));
-	}
-
-	@Override
-	public void addAllErrors(Errors errors) {
-		globalErrors.addAll(errors.getAllErrors());
-	}
-
-	@Override
-	public List<ObjectError> getGlobalErrors() {
-		return globalErrors;
-	}
-
-	@Override
-	public List<FieldError> getFieldErrors() {
-		return fieldErrors;
+	public ConfigurablePropertyAccessor getPropertyAccessor() {
+
+		return new DirectFieldAccessor(getTarget()) {
+
+			@Override
+			public Object getPropertyValue(String propertyName) throws BeansException {
+				PersistentProperty<?> property = entity.getPersistentProperty(propertyName);
+				return property == null ? null : accessor.getProperty(property);
+			}
+		};
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.validation.AbstractBindingResult#getFieldValue(java.lang.String)
+	 */
 	@Override
 	public Object getFieldValue(String field) {
-		PersistentProperty<?> prop = persistentEntity != null ? persistentEntity.getPersistentProperty(field) : null;
-		if (null == prop) {
-			return null;
+
+		if (field.contains(".")) {
+			return super.getFieldValue(field);
 		}
 
-		Method getter = prop.getGetter();
-		if (null != getter) {
-			return invokeMethod(getter, entity);
-		}
-		Field fld = prop.getField();
-		if (null != fld) {
-			return getField(fld, entity);
-		}
-
-		return null;
+		return accessor.getProperty(entity.getPersistentProperty(field));
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.validation.AbstractBindingResult#getTarget()
+	 */
+	@Override
+	public Object getTarget() {
+		return accessor.getBean();
+	}
 }

spring-data-rest-core/src/main/java/org/springframework/data/rest/core/event/ValidatingRepositoryEventListener.java

@@ -23,12 +23,14 @@ import java.util.Map;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.ObjectFactory;
+import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.context.PersistentEntities;
 import org.springframework.data.rest.core.RepositoryConstraintViolationException;
 import org.springframework.data.rest.core.ValidationErrors;
 import org.springframework.util.Assert;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
+import org.springframework.validation.DirectFieldBindingResult;
 import org.springframework.validation.Errors;
 import org.springframework.validation.ValidationUtils;
 import org.springframework.validation.Validator;
@@ -167,8 +169,10 @@ public class ValidatingRepositoryEventListener extends AbstractRepositoryEventLi
 
 		Class<?> domainType = entity.getClass();
 		PersistentEntities persistentEntities = persistentEntitiesFactory.getObject();
-		Errors errors = new ValidationErrors(domainType.getSimpleName(), entity,
-				persistentEntities.getPersistentEntity(domainType));
+		PersistentEntity<?, ?> persistentEntity = persistentEntities.getPersistentEntity(domainType);
+
+		Errors errors = persistentEntity == null ? new DirectFieldBindingResult(entity, domainType.getSimpleName())
+				: new ValidationErrors(entity, persistentEntity);
 
 		for (Validator v : getValidatorsForEvent(event)) {
 

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", "")));
 	}

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/support/RepositoryConstraintViolationExceptionMessage.java

@@ -39,8 +39,8 @@ public class RepositoryConstraintViolationExceptionMessage {
 
 			String message = accessor.getMessage(fieldError);
 
-			this.errors.add(new ValidationError(fieldError.getObjectName(), message, String.format("%s",
-					fieldError.getRejectedValue()), fieldError.getField()));
+			this.errors.add(new ValidationError(fieldError.getObjectName(), message,
+					String.format("%s", fieldError.getRejectedValue()), fieldError.getField()));
 		}
 	}