SPR-8364

org.springframework.core/src/main/java/org/springframework/core/convert/support/ArrayToCollectionConverter.java

@@ -59,11 +59,20 @@ final class ArrayToCollectionConverter implements ConditionalGenericConverter {
 		}		
 		int length = Array.getLength(source);
 		Collection<Object> target = CollectionFactory.createCollection(targetType.getType(), length);
-		for (int i = 0; i < length; i++) {
-			Object sourceElement = Array.get(source, i);
-			Object targetElement = this.conversionService.convert(sourceElement, sourceType.getElementTypeDescriptor(), targetType.getElementTypeDescriptor());
-			target.add(targetElement);
-		}
+		TypeDescriptor sourceElementType = sourceType.getElementTypeDescriptor();
+		TypeDescriptor targetElementType = targetType.getElementTypeDescriptor();
+		if (Object.class.equals(targetElementType.getType())) {
+			for (int i = 0; i < length; i++) {
+				Object sourceElement = Array.get(source, i);
+				target.add(sourceElement);
+			}
+		} else {
+			for (int i = 0; i < length; i++) {
+				Object sourceElement = Array.get(source, i);
+				Object targetElement = this.conversionService.convert(sourceElement, sourceElementType, targetElementType);
+				target.add(targetElement);
+			}
+		}		
 		return target;
 	}
 

org.springframework.core/src/main/java/org/springframework/core/convert/support/CollectionToCollectionConverter.java

@@ -61,9 +61,17 @@ final class CollectionToCollectionConverter implements ConditionalGenericConvert
 		}
 		Collection<?> sourceCollection = (Collection<?>) source;
 		Collection<Object> target = CollectionFactory.createCollection(targetType.getType(), sourceCollection.size());
-		for (Object sourceElement : sourceCollection) {
-			Object targetElement = this.conversionService.convert(sourceElement, sourceType.getElementTypeDescriptor(), targetType.getElementTypeDescriptor());
-			target.add(targetElement);
+		TypeDescriptor sourceElementType = sourceType.getElementTypeDescriptor();
+		TypeDescriptor targetElementType = targetType.getElementTypeDescriptor();
+		if (Object.class.equals(targetElementType.getType())) {
+			for (Object sourceElement : sourceCollection) {
+				target.add(sourceElement);
+			}			
+		} else {
+			for (Object sourceElement : sourceCollection) {
+				Object targetElement = this.conversionService.convert(sourceElement, sourceElementType, targetElementType);
+				target.add(targetElement);
+			}			
 		}
 		return target;
 	}

org.springframework.core/src/main/java/org/springframework/core/convert/support/MapToMapConverter.java

@@ -60,7 +60,9 @@ final class MapToMapConverter implements ConditionalGenericConverter {
 		}
 		Map<Object, Object> sourceMap = (Map<Object, Object>) source;
 		Map<Object, Object> targetMap = CollectionFactory.createMap(targetType.getType(), sourceMap.size());
+		TypeDescriptor sourceKeyType = sourceType.getMapKeyTypeDescriptor();
 		TypeDescriptor targetKeyType = targetType.getMapKeyTypeDescriptor();
+		TypeDescriptor sourceValueType = sourceType.getMapValueTypeDescriptor();
 		TypeDescriptor targetValueType = targetType.getMapValueTypeDescriptor();
 		if (Object.class.equals(targetKeyType.getType()) && Object.class.equals(targetValueType.getType())) {
 			for (Map.Entry<Object, Object> entry : sourceMap.entrySet()) {
@@ -70,8 +72,8 @@ final class MapToMapConverter implements ConditionalGenericConverter {
 			for (Map.Entry<Object, Object> entry : sourceMap.entrySet()) {
 				Object sourceKey = entry.getKey();
 				Object sourceValue = entry.getValue();
-				Object targetKey = this.conversionService.convert(sourceKey, sourceType.getMapKeyTypeDescriptor(), targetType.getMapKeyTypeDescriptor());
-				Object targetValue = this.conversionService.convert(sourceValue, sourceType.getMapValueTypeDescriptor(), targetType.getMapValueTypeDescriptor());
+				Object targetKey = this.conversionService.convert(sourceKey, sourceKeyType, targetKeyType);
+				Object targetValue = this.conversionService.convert(sourceValue, sourceValueType, targetValueType);
 				targetMap.put(targetKey, targetValue);
 			}			
 		}

org.springframework.core/src/main/java/org/springframework/core/convert/support/ObjectToCollectionConverter.java

@@ -55,13 +55,12 @@ final class ObjectToCollectionConverter implements ConditionalGenericConverter {
 			return null;
 		}
 		Collection<Object> target = CollectionFactory.createCollection(targetType.getType(), 1);
-		TypeDescriptor elementType = targetType.getElementTypeDescriptor();
-		// Avoid potential recursion...
-		if (!Collection.class.isAssignableFrom(elementType.getType())) {
-			target.add(this.conversionService.convert(source, sourceType, elementType));
-		}
-		else {
-			target.add(source);
+		TypeDescriptor targetElementType = targetType.getElementTypeDescriptor();
+		// Avoid potential recursion....
+		if (targetElementType.isCollection()) {
+			target.add(source);			
+		} else {
+			target.add(this.conversionService.convert(source, sourceType, targetElementType));
 		}
 		return target;
 	}

org.springframework.core/src/test/java/org/springframework/core/convert/support/CollectionToCollectionConverterTests.java

@@ -1,7 +1,8 @@
 package org.springframework.core.convert.support;
 
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import java.io.File;
 import java.io.IOException;
@@ -9,6 +10,8 @@ import java.io.InputStream;
 import java.net.URI;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.LinkedList;
 import java.util.List;
 
 import org.junit.Before;
@@ -28,6 +31,114 @@ public class CollectionToCollectionConverterTests {
 		conversionService.addConverter(new CollectionToCollectionConverter(conversionService));
 	}
 
+	@Test
+	public void scalarList() throws Exception {
+		List<String> list = new ArrayList<String>();
+		list.add("9");
+		list.add("37");
+		TypeDescriptor sourceType = TypeDescriptor.forObject(list);
+		TypeDescriptor targetType = new TypeDescriptor(getClass().getField("scalarListTarget"));
+		assertFalse(conversionService.canConvert(sourceType, targetType));
+		conversionService.addConverterFactory(new StringToNumberConverterFactory());
+		assertTrue(conversionService.canConvert(sourceType, targetType));
+		@SuppressWarnings("unchecked")		
+		List<String> result = (List<String>) conversionService.convert(list, sourceType, targetType);
+		assertFalse(list.equals(result));
+		assertEquals((Integer) 9, result.get(0));
+		assertEquals((Integer) 37, result.get(1));
+	}
+	
+	public List<Integer> scalarListTarget;
+
+	@Test
+	public void emptyListToList() throws Exception {
+		conversionService.addConverter(new CollectionToCollectionConverter(conversionService));
+		conversionService.addConverterFactory(new StringToNumberConverterFactory());
+		List<String> list = new ArrayList<String>();
+		TypeDescriptor sourceType = TypeDescriptor.forObject(list);
+		TypeDescriptor targetType = new TypeDescriptor(getClass().getField("emptyListTarget"));
+		assertTrue(conversionService.canConvert(sourceType, targetType));
+		assertEquals(list, conversionService.convert(list, sourceType, targetType));
+	}
+
+	public List<Integer> emptyListTarget;
+
+	@Test
+	public void emptyListToListDifferentTargetType() throws Exception {
+		conversionService.addConverter(new CollectionToCollectionConverter(conversionService));
+		conversionService.addConverterFactory(new StringToNumberConverterFactory());
+		List<String> list = new ArrayList<String>();
+		TypeDescriptor sourceType = TypeDescriptor.forObject(list);
+		TypeDescriptor targetType = new TypeDescriptor(getClass().getField("emptyListDifferentTarget"));
+		assertTrue(conversionService.canConvert(sourceType, targetType));
+		@SuppressWarnings("unchecked")
+		LinkedList<Integer> result = (LinkedList<Integer>) conversionService.convert(list, sourceType, targetType);
+		assertEquals(LinkedList.class, result.getClass());
+		assertTrue(result.isEmpty());
+	}
+
+	public LinkedList<Integer> emptyListDifferentTarget;
+
+	@Test
+	public void collectionToObjectInteraction() throws Exception {
+		List<List<String>> list = new ArrayList<List<String>>();
+		list.add(Arrays.asList("9", "12"));
+		list.add(Arrays.asList("37", "23"));
+		conversionService.addConverter(new CollectionToObjectConverter(conversionService));
+		assertTrue(conversionService.canConvert(List.class, List.class));
+		assertEquals(list, conversionService.convert(list, List.class));
+	}
+
+	@Test
+	public void arrayCollectionToObjectInteraction() throws Exception {
+		List<String>[] array = new List[2];
+		array[0] = Arrays.asList("9", "12");
+		array[1] = Arrays.asList("37", "23");
+		conversionService.addConverter(new ArrayToCollectionConverter(conversionService));
+		conversionService.addConverter(new CollectionToObjectConverter(conversionService));
+		assertTrue(conversionService.canConvert(String[].class, List.class));
+		assertEquals(Arrays.asList(array), conversionService.convert(array, List.class));
+	}
+
+	@Test
+	public void objectToCollection() throws Exception {
+		List<List<String>> list = new ArrayList<List<String>>();
+		list.add(Arrays.asList("9", "12"));
+		list.add(Arrays.asList("37", "23"));
+		conversionService.addConverterFactory(new StringToNumberConverterFactory());
+		conversionService.addConverter(new ObjectToCollectionConverter(conversionService));
+		conversionService.addConverter(new CollectionToObjectConverter(conversionService));
+		TypeDescriptor sourceType = TypeDescriptor.forObject(list);
+		TypeDescriptor targetType = new TypeDescriptor(getClass().getField("objectToCollection"));
+		assertTrue(conversionService.canConvert(sourceType, targetType));
+		List<List<List<Integer>>> result = (List<List<List<Integer>>>) conversionService.convert(list, sourceType, targetType);
+		assertEquals((Integer)9, result.get(0).get(0).get(0));
+		assertEquals((Integer)12, result.get(0).get(1).get(0));
+		assertEquals((Integer)37, result.get(1).get(0).get(0));
+		assertEquals((Integer)23, result.get(1).get(1).get(0));
+	}
+
+	public List<List<List<Integer>>> objectToCollection;
+	
+	@Test
+	public void stringToCollection() throws Exception {
+		List<List<String>> list = new ArrayList<List<String>>();
+		list.add(Arrays.asList("9,12"));
+		list.add(Arrays.asList("37,23"));
+		conversionService.addConverterFactory(new StringToNumberConverterFactory());
+		conversionService.addConverter(new StringToCollectionConverter(conversionService));
+		conversionService.addConverter(new ObjectToCollectionConverter(conversionService));		
+		conversionService.addConverter(new CollectionToObjectConverter(conversionService));
+		TypeDescriptor sourceType = TypeDescriptor.forObject(list);
+		TypeDescriptor targetType = new TypeDescriptor(getClass().getField("objectToCollection"));
+		assertTrue(conversionService.canConvert(sourceType, targetType));
+		List<List<List<Integer>>> result = (List<List<List<Integer>>>) conversionService.convert(list, sourceType, targetType);
+		assertEquals((Integer)9, result.get(0).get(0).get(0));
+		assertEquals((Integer)12, result.get(0).get(0).get(1));
+		assertEquals((Integer)37, result.get(1).get(0).get(0));
+		assertEquals((Integer)23, result.get(1).get(0).get(1));
+	}
+
 	@Test
 	public void differentImpls() throws Exception {
 		List<Resource> resources = new ArrayList<Resource>();
@@ -69,7 +180,7 @@ public class CollectionToCollectionConverterTests {
 
 	public List<Resource> resources;
 
-	public static  abstract class BaseResource implements Resource {
+	public static abstract class BaseResource implements Resource {
 
 		public InputStream getInputStream() throws IOException {
 			// TODO Auto-generated method stub

org.springframework.core/src/test/java/org/springframework/core/convert/support/GenericConversionServiceTests.java

@@ -16,7 +16,16 @@
 
 package org.springframework.core.convert.support;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -24,9 +33,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 
-import static org.junit.Assert.*;
 import org.junit.Test;
-
 import org.springframework.core.convert.ConversionFailedException;
 import org.springframework.core.convert.ConverterNotFoundException;
 import org.springframework.core.convert.TypeDescriptor;
@@ -261,8 +268,13 @@ public class GenericConversionServiceTests {
 	@Test
 	public void testListOfList() {
 		GenericConversionService service = new DefaultConversionService();
-		List<List<String>> list = Collections.singletonList(Collections.singletonList("Foo"));
-		assertNotNull(service.convert(list, String.class));
+		List<String> list1 = Arrays.asList("Foo", "Bar");
+		List<String> list2 = Arrays.asList("Baz", "Boop");
+		@SuppressWarnings("unchecked")
+		List<List<String>> list = Arrays.asList(list1, list2);
+		String result = service.convert(list, String.class);
+		assertNotNull(result);
+		assertEquals("Foo,Bar,Baz,Boop", result);
 	}
 
 	@Test
@@ -360,36 +372,6 @@ public class GenericConversionServiceTests {
 	
 	public static Map<String, Integer> map;
 
-
-	@Test
-	public void emptyListToList() throws Exception {
-		conversionService.addConverter(new CollectionToCollectionConverter(conversionService));
-		conversionService.addConverterFactory(new StringToNumberConverterFactory());
-		List<String> list = new ArrayList<String>();
-		TypeDescriptor sourceType = TypeDescriptor.forObject(list);
-		TypeDescriptor targetType = new TypeDescriptor(getClass().getField("emptyListTarget"));
-		assertTrue(conversionService.canConvert(sourceType, targetType));
-		assertEquals(list, conversionService.convert(list, sourceType, targetType));
-	}
-
-	public List<Integer> emptyListTarget;
-
-	@Test
-	public void emptyListToListDifferentTargetType() throws Exception {
-		conversionService.addConverter(new CollectionToCollectionConverter(conversionService));
-		conversionService.addConverterFactory(new StringToNumberConverterFactory());
-		List<String> list = new ArrayList<String>();
-		TypeDescriptor sourceType = TypeDescriptor.forObject(list);
-		TypeDescriptor targetType = new TypeDescriptor(getClass().getField("emptyListDifferentTarget"));
-		assertTrue(conversionService.canConvert(sourceType, targetType));
-		@SuppressWarnings("unchecked")
-		LinkedList<Integer> result = (LinkedList<Integer>) conversionService.convert(list, sourceType, targetType);
-		assertEquals(LinkedList.class, result.getClass());
-		assertTrue(result.isEmpty());
-	}
-
-	public LinkedList<Integer> emptyListDifferentTarget;
-
 	@Test
 	public void emptyListToArray() throws Exception {
 		conversionService.addConverter(new CollectionToArrayConverter(conversionService));

org.springframework.core/src/test/java/org/springframework/core/convert/support/MapToMapConverterTests.java

@@ -52,7 +52,7 @@ public class MapToMapConverterTests {
 	}
 
 	@Test
-	public void scalarMapNotGenericSource() throws Exception {
+	public void scalarMapNotGenericSourceField() throws Exception {
 		Map<String, String> map = new HashMap<String, String>();
 		map.put("1", "9");
 		map.put("2", "37");
@@ -117,6 +117,7 @@ public class MapToMapConverterTests {
 		Map<String, List<String>> map = new HashMap<String, List<String>>();
 		map.put("1", Arrays.asList("9", "12"));
 		map.put("2", Arrays.asList("37", "23"));
+		conversionService.addConverter(new CollectionToCollectionConverter(conversionService));
 		conversionService.addConverter(new CollectionToObjectConverter(conversionService));
 		assertTrue(conversionService.canConvert(Map.class, Map.class));
 		assertEquals(map, conversionService.convert(map, Map.class));
@@ -127,7 +128,7 @@ public class MapToMapConverterTests {
 		Map<String, String> map = new HashMap<String, String>();
 		TypeDescriptor sourceType = TypeDescriptor.forObject(map);
 		TypeDescriptor targetType = new TypeDescriptor(getClass().getField("emptyMapTarget"));
-		//assertTrue(conversionService.canConvert(sourceType, targetType));
+		assertTrue(conversionService.canConvert(sourceType, targetType));
 		assertEquals(map, conversionService.convert(map, sourceType, targetType));
 	}
 

org.springframework.core/src/test/resources/log4j.xml

@@ -11,7 +11,7 @@
 		</layout>
 	</appender>
 
-	<logger name="org.springframework.core">
+	<logger name="org.springframework.core.convert">
 		<level value="warn" />
 	</logger>