DATACMNS-55 - TypeDiscoverer now handles types extending Collections and Maps as well.

spring-data-commons-core/src/main/java/org/springframework/data/util/TypeDiscoverer.java

@@ -246,12 +246,16 @@ class TypeDiscoverer<S> implements TypeInformation<S> {
 		 */
 	public TypeInformation<?> getMapValueType() {
 
-		if (!Map.class.isAssignableFrom(getType())) {
+		if (!isMap()) {
 			return null;
 		}
-
-		ParameterizedType parameterizedType = (ParameterizedType) type;
-		return createInfo(parameterizedType.getActualTypeArguments()[1]);
+		
+		if (type instanceof ParameterizedType) {
+			ParameterizedType parameterizedType = (ParameterizedType) type;
+			return createInfo(parameterizedType.getActualTypeArguments()[1]);
+		} 
+		
+		return createInfo(GenericTypeResolver.resolveTypeArguments(getType(), Map.class)[1]);
 	}
 
 	/* (non-Javadoc)
@@ -268,12 +272,30 @@ class TypeDiscoverer<S> implements TypeInformation<S> {
 		 */
 	public TypeInformation<?> getComponentType() {
 
-		if (!(Map.class.isAssignableFrom(getType()) || isCollectionLike())) {
+		if (!(isMap() || isCollectionLike())) {
 			return null;
 		}
 
-		ParameterizedType parameterizedType = (ParameterizedType) type;
-		return createInfo(parameterizedType.getActualTypeArguments()[0]);
+		if (type instanceof ParameterizedType) {
+			ParameterizedType parameterizedType = (ParameterizedType) type;
+			return createInfo(parameterizedType.getActualTypeArguments()[0]);
+		}
+		
+		Class<S> rawType = getType();
+		
+		if (isMap()) {
+			return createInfo(GenericTypeResolver.resolveTypeArguments(rawType, Map.class)[0]);
+		}
+		
+		if (Iterable.class.isAssignableFrom(rawType)) {
+			return createInfo(GenericTypeResolver.resolveTypeArguments(rawType, Iterable.class)[0]);
+		}
+		
+		if (rawType.isArray()) {
+			return createInfo(rawType.getComponentType());
+		}
+		
+		return null;
 	}
 
 	/*

spring-data-commons-core/src/test/java/org/springframework/data/util/TypeDiscovererUnitTests.java

@@ -15,11 +15,15 @@
  */
 package org.springframework.data.util;
 
+import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
 
 import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
+import java.util.Collection;
+import java.util.Locale;
 import java.util.Map;
+import java.util.Properties;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -84,6 +88,25 @@ public class TypeDiscovererUnitTests {
 		TypeInformation<?> mapValueType = information.getProperty("map").getMapValueType();
 		assertEquals(mapValueType, information);
 	}
+	
+	@Test
+	public void returnsComponentAndValueTypesForMapExtensions() {
+		TypeDiscoverer<Properties> discoverer = new TypeDiscoverer<Properties>(CustomMap.class, null);
+		assertEquals(Locale.class, discoverer.getMapValueType().getType());
+		assertEquals(String.class, discoverer.getComponentType().getType());
+	}
+	
+ 	@Test
+ 	public void returnsComponentTypeForCollectionExtension() {
+ 		TypeDiscoverer<CustomCollection> discoverer = new TypeDiscoverer<CustomCollection>(CustomCollection.class, null);
+ 		assertEquals(String.class, discoverer.getComponentType().getType());
+ 	}
+ 	
+ 	@Test
+ 	public void returnsComponentTypeForArrays() {
+ 		TypeDiscoverer<String[]> discoverer = new TypeDiscoverer<String[]>(String[].class, null);
+ 		assertEquals(String.class, discoverer.getComponentType().getType());
+ 	}
 
 	class SelfReferencing {
 
@@ -93,4 +116,12 @@ public class TypeDiscovererUnitTests {
 	class SelfReferencingMap {
 		Map<String, SelfReferencingMap> map;
 	}
+
+  interface CustomMap extends Map<String, Locale> {
+  	
+  }
+  
+  interface CustomCollection extends Collection<String> {
+  	
+  }
 }