SPR-9498: Add support for MultiValueMap to CollectionFactory

This turns out not to be the main problem exposed in SPR-9498
but it seems like a sensible addition anyway.

spring-core/src/main/java/org/springframework/core/CollectionFactory.java

@@ -35,6 +35,8 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArraySet;
 
 import org.springframework.util.LinkedCaseInsensitiveMap;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
 
 /**
  * Factory for collections, being aware of Java 5 and Java 6 collections.
@@ -305,6 +307,9 @@ public abstract class CollectionFactory {
 			else if (SortedMap.class.equals(mapType) || mapType.equals(navigableMapClass)) {
 				return new TreeMap();
 			}
+			else if (MultiValueMap.class.equals(mapType)) {
+				return new LinkedMultiValueMap();
+			}
 			else {
 				throw new IllegalArgumentException("Unsupported Map interface: " + mapType.getName());
 			}

spring-core/src/test/java/org/springframework/core/CollectionFactoryTests.java

@@ -24,9 +24,12 @@ import java.util.Set;
 
 import junit.framework.TestCase;
 
+import org.springframework.util.MultiValueMap;
+
 /**
  * @author Darren Davison
  * @author Juergen Hoeller
+ * @author Dave Syer
  */
 public class CollectionFactoryTests extends TestCase {
 
@@ -50,6 +53,11 @@ public class CollectionFactoryTests extends TestCase {
 		assertTrue(map.getClass().getName().endsWith("ConcurrentHashMap"));
 	}
 
+	public void testMultiValueMap() {
+		Map map = CollectionFactory.createMap(MultiValueMap.class, 16);
+		assertTrue(map.getClass().getName().endsWith("MultiValueMap"));
+	}
+
 	public void testConcurrentMapWithExplicitInterface() {
 		ConcurrentMap map = CollectionFactory.createConcurrentMap(16);
 		assertTrue(map.getClass().getSuperclass().getName().endsWith("ConcurrentHashMap"));