DATAREST-1326 - Fix ClassCastException JsonSchema for a list of Enums.

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/JacksonSerializers.java

@@ -18,6 +18,8 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.springframework.data.rest.webmvc.json.JsonSchema.EnumProperty;
 import org.springframework.data.rest.webmvc.json.JsonSchema.JsonSchemaProperty;
@@ -44,8 +46,9 @@
  * Custom Spring Data REST Jackson serializers.
  *
  * @author Oliver Gierke
- * @since 2.4
+ * @author Doug Busley
  * @soundtrack Wallis Bird - I Could Be Your Man (Yeah! Wallis Bird Live 2007-2014)
+ * @since 2.4
  */
 public class JacksonSerializers extends SimpleModule {
 
@@ -117,7 +120,14 @@ public JsonSchemaProperty customize(JsonSchemaProperty property, TypeInformation
 				values.add(translator.asText((Enum<?>) value));
 			}
 
-			return ((EnumProperty) property).withValues(values);
+			if (property instanceof EnumProperty) {
+				return ((EnumProperty) property).withValues(values);
+			}
+
+			property.items = Stream.of(new Object[][]{{"enum", values}, {"type", "string"}})
+					.collect(Collectors.toMap(data -> (String) data[0], data -> data[1]));
+
+			return property;
 		}
 	}
 

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/JsonSchema.java

@@ -46,6 +46,7 @@
  *
  * @author Jon Brisbin
  * @author Oliver Gierke
+ * @author Doug Busley
  */
 @JsonInclude(Include.NON_EMPTY)
 public class JsonSchema {
@@ -333,7 +334,7 @@ public static class JsonSchemaProperty extends AbstractJsonSchemaProperty<JsonSc
 		public String pattern;
 		public Boolean uniqueItems;
 		public @JsonProperty("$ref") String reference;
-		public Map<String, String> items;
+		public Map<String, Object> items;
 
 		JsonSchemaProperty(String name, String title, String description, boolean required) {
 

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

@@ -17,18 +17,23 @@
 
 import static org.assertj.core.api.Assertions.*;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Locale;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.context.i18n.LocaleContextHolder;
 import org.springframework.context.support.StaticMessageSource;
+import org.springframework.data.util.ClassTypeInformation;
+import org.springframework.data.util.TypeInformation;
 import org.springframework.hateoas.mediatype.MessageResolver;
 
 /**
  * Unit tests for {@link EnumTranslator}.
  *
  * @author Oliver Gierke
+ * @author Doug Busley
  */
 public class EnumTranslatorUnitTests {
 
@@ -145,6 +150,32 @@ public void doesNotResolveEnumNameAsFallbackIfConfigured() {
 		assertThat(configuration.fromText(MyEnum.class, "SECOND_VALUE")).isNull();
 	}
 
+	@Test // DATAREST-1326
+	@SuppressWarnings("unchecked")
+	public void doesNotFailOnEnumListsWithEnumTranslation() {
+		final TypeInformation<?> type = ClassTypeInformation.from(MyEnum.class);
+
+		JsonSchema.JsonSchemaProperty jsonSchemaProperty =
+				new JsonSchema.JsonSchemaProperty("foo", null, "bar", true)
+						.with(ClassTypeInformation.from(List.class));
+		JacksonSerializers.EnumTranslatingSerializer serializer = new
+				JacksonSerializers.EnumTranslatingSerializer(configuration);
+		JsonSchema.JsonSchemaProperty result = serializer.customize(jsonSchemaProperty, type);
+
+		ArrayList<String> enums = (ArrayList<String>) result.items.get("enum");
+
+		// Enum values are placed in the items object
+		assertThat(enums.size()).isEqualTo(2);
+		assertThat(enums.get(0)).isEqualTo("Translated");
+		assertThat(enums.get(1)).isEqualTo("Second value");
+
+		// type of the result object is array
+		assertThat(result.type).isEqualTo("array");
+
+		// type of the items object is string
+		assertThat(result.items.get("type")).isEqualTo("string");
+	}
+
 	static enum MyEnum {
 		FIRST_VALUE, SECOND_VALUE;
 	}