DATAREST-929 - EnumTranslatingDeserializers now handles container types correctly.

When translating enumerations, we now inspect the property and use a container type's value type as translation target.

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/JacksonSerializers.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.
@@ -29,6 +29,7 @@ import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.BeanProperty;
 import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JavaType;
 import com.fasterxml.jackson.databind.JsonDeserializer;
 import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.SerializerProvider;
@@ -181,7 +182,18 @@ public class JacksonSerializers extends SimpleModule {
 				throw new IllegalStateException("Can only translate enum with property information!");
 			}
 
-			return translator.fromText((Class<? extends Enum<?>>) property.getType().getRawClass(), p.getText());
+			return translator.fromText((Class<? extends Enum<?>>) getActualType(property.getType()).getRawClass(),
+					p.getText());
+		}
+
+		/**
+		 * Returns the value types for containers or the original type otherwise.
+		 * 
+		 * @param type must not be {@literal null}.
+		 * @return
+		 */
+		private static JavaType getActualType(JavaType type) {
+			return type.isContainerType() ? type.getContentType() : type;
 		}
 	}
 }

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/json/JacksonSerializersUnitTests.java

@@ -0,0 +1,106 @@
+/*
+ * 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.webmvc.json;
+
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+
+import java.util.Collection;
+import java.util.Map;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.data.rest.webmvc.json.JacksonSerializersUnitTests.Sample.SampleEnum;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * Unit tests for {@link JacksonSerializers}.
+ * 
+ * @author Oliver Gierke
+ * @soundtrack James Bay - Move Together (Chaos And The Calm)
+ */
+public class JacksonSerializersUnitTests {
+
+	ObjectMapper mapper;
+
+	@Before
+	public void setUp() {
+
+		EnumTranslator translator = mock(EnumTranslator.class);
+		doReturn(SampleEnum.VALUE).when(translator).fromText(SampleEnum.class, "value");
+
+		this.mapper = new ObjectMapper();
+		this.mapper.registerModule(new JacksonSerializers(translator));
+	}
+
+	/**
+	 * @see DATAREST-929
+	 */
+	@Test
+	public void translatesPlainEnumCorrectly() throws Exception {
+
+		Sample result = mapper.readValue("{ \"property\" : \"value\"}", Sample.class);
+
+		assertThat(result.property, is(SampleEnum.VALUE));
+	}
+
+	/**
+	 * @see DATAREST-929
+	 */
+	@Test
+	public void translatesCollectionOfEnumsCorrectly() throws Exception {
+
+		Sample result = mapper.readValue("{ \"collection\" : [ \"value\" ] }", Sample.class);
+
+		assertThat(result.collection, hasItem(SampleEnum.VALUE));
+	}
+
+	/**
+	 * @see DATAREST-929
+	 */
+	@Test
+	public void translatesEnumArraysCorrectly() throws Exception {
+
+		Sample result = mapper.readValue("{ \"array\" : [ \"value\" ] }", Sample.class);
+
+		assertThat(result.array, hasItemInArray(SampleEnum.VALUE));
+	}
+
+	/**
+	 * @see DATAREST-929
+	 */
+	@Test
+	public void translatesMapEnumValueCorrectly() throws Exception {
+
+		Sample result = mapper.readValue("{ \"mapToEnum\" : { \"foo\" : \"value\" } }", Sample.class);
+
+		assertThat(result.mapToEnum.get("foo"), is(SampleEnum.VALUE));
+	}
+
+	static class Sample {
+
+		enum SampleEnum {
+			VALUE;
+		}
+
+		public SampleEnum property;
+		public Collection<SampleEnum> collection;
+		public SampleEnum[] array;
+		public Map<String, SampleEnum> mapToEnum;
+	}
+}