merging values passed in path params with deserialized values

vraptor-core/pom.xml

@@ -57,6 +57,12 @@
 				</exclusion>
 			</exclusions>
 		</dependency>
+
+		<dependency>
+			<groupId>commons-beanutils</groupId>
+			<artifactId>commons-beanutils</artifactId>
+			<version>1.9.2</version>
+		</dependency>
 		<!-- /mandatory -->
 
 

vraptor-core/src/main/java/br/com/caelum/vraptor/observer/DeserializingObserver.java

@@ -33,9 +33,11 @@
 import br.com.caelum.vraptor.core.MethodInfo;
 import br.com.caelum.vraptor.events.InterceptorsReady;
 import br.com.caelum.vraptor.events.MethodReady;
+import br.com.caelum.vraptor.http.ValuedParameter;
 import br.com.caelum.vraptor.ioc.Container;
 import br.com.caelum.vraptor.serialization.Deserializer;
 import br.com.caelum.vraptor.serialization.Deserializers;
+import br.com.caelum.vraptor.util.ObjectMerger;
 import br.com.caelum.vraptor.view.Status;
 
 /**
@@ -51,20 +53,22 @@ public class DeserializingObserver {
 
 	private final Deserializers deserializers;
 	private final Container container;
+	private final ObjectMerger objectMerger;
 
 	private static final Logger logger = getLogger(DeserializingObserver.class);
 
 	/**
 	 * @deprecated CDI eyes only
 	 */
 	protected DeserializingObserver() {
-		this(null, null);
+		this(null, null, null);
 	}
 
 	@Inject
-	public DeserializingObserver(Deserializers deserializers, Container container) {
+	public DeserializingObserver(Deserializers deserializers, Container container, ObjectMerger objectMerger) {
 		this.deserializers = deserializers;
 		this.container = container;
+		this.objectMerger = objectMerger;
 	}
 
 	public void deserializes(@Observes InterceptorsReady event, HttpServletRequest request,
@@ -96,9 +100,20 @@ public void deserializes(@Observes InterceptorsReady event, HttpServletRequest r
 		Object[] deserialized = deserializer.deserialize(request.getInputStream(), method);
 		logger.debug("Deserialized parameters for {} are {} ", method, deserialized);
 
+		ValuedParameter[] valuedParameters = methodInfo.getValuedParameters();
+
 		for (int i = 0; i < deserialized.length; i++) {
 			if (deserialized[i] != null) {
-				methodInfo.setParameter(i, deserialized[i]);
+				ValuedParameter valuedParameter = valuedParameters[i];
+				Object existingValue = valuedParameter.getValue();
+				Object deserializedValue = deserialized[i];
+
+				if (existingValue == null) {
+					methodInfo.setParameter(i, deserializedValue);
+				} else {
+					Object mergedValue = objectMerger.merge(deserializedValue, existingValue);
+					methodInfo.setParameter(i, mergedValue);
+				}
 			}
 		}
 	}

vraptor-core/src/main/java/br/com/caelum/vraptor/observer/ParametersInstantiator.java

@@ -38,6 +38,7 @@
 import br.com.caelum.vraptor.http.Parameter;
 import br.com.caelum.vraptor.http.ParametersProvider;
 import br.com.caelum.vraptor.http.ValuedParameter;
+import br.com.caelum.vraptor.util.ObjectMerger;
 import br.com.caelum.vraptor.validator.Message;
 import br.com.caelum.vraptor.validator.Validator;
 import br.com.caelum.vraptor.view.FlashScope;
@@ -59,24 +60,26 @@ public class ParametersInstantiator {
 	private final Validator validator;
 	private final MutableRequest request;
 	private final FlashScope flash;
+	private final ObjectMerger objectMerger;
 
 	private final List<Message> errors = new ArrayList<>();
 
 	/**
 	 * @deprecated CDI eyes only
 	 */
 	protected ParametersInstantiator() {
-		this(null, null, null, null, null);
+		this(null, null, null, null, null, null);
 	}
 
 	@Inject
 	public ParametersInstantiator(ParametersProvider provider, MethodInfo methodInfo, Validator validator, 
-			MutableRequest request, FlashScope flash) {
+			MutableRequest request, FlashScope flash, ObjectMerger objectMerger) {
 		this.provider = provider;
 		this.methodInfo = methodInfo;
 		this.validator = validator;
 		this.request = request;
 		this.flash = flash;
+		this.objectMerger = objectMerger;
 	}
 
 	public void instantiate(@Observes InterceptorsReady event) {
@@ -101,8 +104,14 @@ public void instantiate(@Observes InterceptorsReady event) {
 				valuedParameters[i].setValue(request.getHeader(headerParam.value()));
 			} else {
 				ValuedParameter valuedParameter = valuedParameters[i];
-				if (valuedParameter.getValue() == null) {
-					valuedParameter.setValue(values[i]);
+				Object existingValue = valuedParameter.getValue();
+				Object value = values[i];
+
+				if (existingValue == null) {
+					valuedParameter.setValue(value);
+				} else {
+					Object mergedValue = objectMerger.merge(existingValue, value);
+					valuedParameter.setValue(mergedValue);
 				}
 			}
 		}

vraptor-core/src/main/java/br/com/caelum/vraptor/util/ObjectMergeException.java

@@ -0,0 +1,33 @@
+/***
+ * Copyright (c) 2009 Caelum - www.caelum.com.br/opensource All rights reserved.
+ *
+ * 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 br.com.caelum.vraptor.util;
+
+import br.com.caelum.vraptor.VRaptorException;
+
+/**
+ * This exception is thrown when we have some problem trying to merge objects
+ *
+ * @author Nykolas Lima
+ */
+public class ObjectMergeException extends VRaptorException {
+
+	private static final long serialVersionUID = 7057844184695106988L;
+
+	public ObjectMergeException(String msg, Throwable e) {
+		super(msg, e);
+	}
+
+}

vraptor-core/src/main/java/br/com/caelum/vraptor/util/ObjectMerger.java

@@ -0,0 +1,52 @@
+/***
+ * Copyright (c) 2009 Caelum - www.caelum.com.br/opensource All rights reserved.
+ *
+ * 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 br.com.caelum.vraptor.util;
+
+import java.lang.reflect.InvocationTargetException;
+
+import javax.enterprise.context.RequestScoped;
+
+import org.apache.commons.beanutils.BeanUtilsBean;
+
+/**
+ * This classes is used to merge 2 objects ignoring Null values.
+ * 
+ * It's used by our parameter's resolvers
+ *
+ * @author Nykolas Lima
+ */
+@RequestScoped
+public class ObjectMerger {
+
+	public Object merge(Object dest, Object from) {
+		try {
+			new BeanUtilsBean() {
+			    @Override
+			    public void copyProperty(Object dest, String name, Object value) throws IllegalAccessException, InvocationTargetException {
+			        //do not override null values
+			    	if(value != null) {
+			            super.copyProperty(dest, name, value);
+			        }
+			    }
+			}.copyProperties(dest, from);
+
+			return dest;
+		} catch (IllegalAccessException | InvocationTargetException e) {
+			throw new ObjectMergeException(String.format("Error trying to merge values from %s", dest.getClass().getName()), e);
+		}
+	}
+
+}

vraptor-core/src/test/java/br/com/caelum/vraptor/observer/DeserializingAndInstantiatorIntegrationTest.java

@@ -20,6 +20,7 @@
 import br.com.caelum.vraptor.ioc.Container;
 import br.com.caelum.vraptor.serialization.Deserializer;
 import br.com.caelum.vraptor.serialization.Deserializers;
+import br.com.caelum.vraptor.util.ObjectMerger;
 import br.com.caelum.vraptor.validator.Message;
 import br.com.caelum.vraptor.validator.Validator;
 import br.com.caelum.vraptor.view.FlashScope;
@@ -36,6 +37,7 @@ public class DeserializingAndInstantiatorIntegrationTest {
 	@Mock private Container container;
 	@Mock private Status status;
 	@Mock private Deserializer deserializer;
+	private ObjectMerger objectMerger;
 
 	private MethodInfo methodInfo;
 	private ParametersInstantiator instantiator;
@@ -50,9 +52,10 @@ public void setUp() throws Exception {
 		when(deserializers.deserializerFor("application/xml", container)).thenReturn(deserializer);
 		when(request.getContentType()).thenReturn("application/xml");
 
+		objectMerger = new ObjectMerger();
 		methodInfo = new MethodInfo(new ParanamerNameProvider());
-		instantiator = new ParametersInstantiator(provider, methodInfo, validator, request, flash);
-		deserializing = new DeserializingObserver(deserializers, container);
+		instantiator = new ParametersInstantiator(provider, methodInfo, validator, request, flash, objectMerger);
+		deserializing = new DeserializingObserver(deserializers, container, objectMerger);
 
 		controllerMethod = new DefaultControllerMethod(null, DeserializingObserverTest
 				.DummyResource.class.getDeclaredMethod("consumeXml", String.class, String.class));

vraptor-core/src/test/java/br/com/caelum/vraptor/observer/DeserializingObserverTest.java

@@ -21,6 +21,8 @@
 import static org.mockito.Mockito.verifyZeroInteractions;
 import static org.mockito.Mockito.when;
 
+import java.io.IOException;
+
 import javax.servlet.http.HttpServletRequest;
 
 import org.junit.Before;
@@ -37,14 +39,17 @@
 import br.com.caelum.vraptor.ioc.Container;
 import br.com.caelum.vraptor.serialization.Deserializer;
 import br.com.caelum.vraptor.serialization.Deserializers;
+import br.com.caelum.vraptor.util.ObjectMerger;
 import br.com.caelum.vraptor.view.Status;
 
 
 public class DeserializingObserverTest {
 	private DeserializingObserver observer;
 	private ControllerMethod consumeXml;
 	private ControllerMethod doesntConsume;
+	private ControllerMethod consumeClientXml;
 	private MethodInfo methodInfo;
+	private ObjectMerger objectMerger;
 
 	@Mock private HttpServletRequest request;
 	@Mock Deserializers deserializers;
@@ -57,9 +62,12 @@ public void setUp() throws Exception {
 
 		methodInfo = new MethodInfo(new ParanamerNameProvider());
 
-		observer = new DeserializingObserver(deserializers, container);
+		objectMerger = new ObjectMerger();
+
+		observer = new DeserializingObserver(deserializers, container, objectMerger);
 		consumeXml = new DefaultControllerMethod(null, DummyResource.class.getDeclaredMethod("consumeXml", String.class, String.class));
 		doesntConsume = new DefaultControllerMethod(null, DummyResource.class.getDeclaredMethod("doesntConsume"));
+		consumeClientXml = new DefaultControllerMethod(null, DummyResource.class.getDeclaredMethod("addClient", Client.class));
 	}
 
 
@@ -71,6 +79,9 @@ public void consumeXml(String a, String b) {}
 		public void consumesAnything(String a, String b) {}
 
 		public void doesntConsume() {}
+
+		@Consumes("application/xml")
+		public void addClient(Client client) {}
 	}
 
 	@Test
@@ -178,4 +189,58 @@ public void willSetOnlyNonNullParameters() throws Exception {
 		assertEquals(methodInfo.getValuedParameters()[0].getValue(), "original1");
 		assertEquals(methodInfo.getValuedParameters()[1].getValue(), "deserialized");
 	}
+
+	@Test
+	public void shouldOverrideDeserializedAttributeWithAlreadyInstantiatedValue() throws IOException {
+		final Deserializer deserializer = mock(Deserializer.class);
+		methodInfo.setControllerMethod(consumeClientXml);
+
+		Client alreadInstantiatedClient = new Client(2, null, 18);
+		methodInfo.setParameter(0, alreadInstantiatedClient);
+
+		Client deserializedClient = new Client(1, "nykolas", null);
+
+		when(request.getContentType()).thenReturn("application/xml");
+		when(deserializer.deserialize(null, consumeXml)).thenReturn(new Object[] {deserializedClient});
+
+		when(deserializers.deserializerFor("application/xml", container)).thenReturn(deserializer);
+		observer.deserializes(new InterceptorsReady(consumeXml), request, methodInfo, status);
+
+		Client mergedClient = (Client) methodInfo.getValuedParameters()[0].getValue();
+		assertEquals(2, mergedClient.getId().intValue());
+		assertEquals("nykolas", mergedClient.getName());
+		assertEquals(18, mergedClient.getAge().intValue());
+	}
+
+	public class Client {
+		public Integer id;
+		public String name;
+		public Integer age;
+
+		public Client(Integer id, String nome, Integer age) {
+			this.id = id;
+			this.name = nome;
+			this.age = age;
+		}
+
+		public Integer getId() {
+			return id;
+		}
+		public String getName() {
+			return name;
+		}
+		public Integer getAge() {
+			return age;
+		}
+		public void setId(Integer id) {
+			this.id = id;
+		}
+		public void setName(String name) {
+			this.name = name;
+		}
+		public void setAge(Integer age) {
+			this.age = age;
+		}
+	}
+
 }