DATACMNS-909 - Mask getDecoratedClass() of Spring 4.3's DecoratingProxy.

The proxies created for projections now defensively mask getDecoratedClass(), a method declared on DecoratingProxy, an interface that JDK proxies on Spring 4.3 will implement.

pom.xml

@@ -205,6 +205,15 @@
 			<version>1.2</version>
 			<scope>test</scope>
 		</dependency>
+		
+		<!-- JSONPath -->
+		
+		<dependency>
+			<groupId>com.jayway.jsonpath</groupId>
+			<artifactId>json-path</artifactId>
+			<version>2.0.0</version>
+			<scope>test</scope>
+		</dependency>
 
 	</dependencies>
 

src/main/java/org/springframework/data/projection/TargetAware.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 the original author or authors.
+ * Copyright 2015-2016 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.
@@ -41,4 +41,13 @@ public interface TargetAware extends org.springframework.aop.TargetClassAware, R
 	 */
 	@JsonIgnore
 	Object getTarget();
+
+	/**
+	 * Re-declaration of Spring Framework 4.3's {@link org.springframework.core.DecoratingProxy#getDecoratedClass()} so
+	 * that we can exclude it from Jackson serialization.
+	 * 
+	 * @return
+	 */
+	@JsonIgnore
+	Class<?> getDecoratedClass();
 }

src/test/java/org/springframework/data/projection/ProjectionIntegrationTests.java

@@ -0,0 +1,55 @@
+/*
+ * 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.projection;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.jayway.jsonpath.Configuration.ConfigurationBuilder;
+import com.jayway.jsonpath.DocumentContext;
+import com.jayway.jsonpath.JsonPath;
+import com.jayway.jsonpath.Option;
+import com.jayway.jsonpath.ParseContext;
+
+/**
+ * Integration tests for projections.
+ * 
+ * @author Oliver Gierke
+ */
+public class ProjectionIntegrationTests {
+
+	/**
+	 * @see DATACMNS-909
+	 */
+	@Test
+	public void jacksonSerializationDoesNotExposeDecoratedClass() throws Exception {
+
+		ProxyProjectionFactory factory = new ProxyProjectionFactory();
+		SampleProjection projection = factory.createProjection(SampleProjection.class);
+
+		ParseContext context = JsonPath.using(new ConfigurationBuilder().options(Option.SUPPRESS_EXCEPTIONS).build());
+		DocumentContext json = context.parse(new ObjectMapper().writeValueAsString(projection));
+
+		assertThat(json.read("$.decoratedClass", String.class), is(nullValue()));
+	}
+
+	interface SampleProjection {
+		String getName();
+	}
+}