SPR-8465

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

@@ -16,14 +16,13 @@
 
 package org.springframework.core.convert.support;
 
-import java.util.Arrays;
+import java.lang.reflect.Array;
 import java.util.Collections;
 import java.util.Set;
 
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.core.convert.converter.ConditionalGenericConverter;
-import org.springframework.util.ObjectUtils;
 
 /**
  * Converts an Array to an Object by returning the first array element after converting it to the desired targetType.
@@ -34,10 +33,10 @@ import org.springframework.util.ObjectUtils;
  */
 final class ArrayToObjectConverter implements ConditionalGenericConverter {
 
-	private final CollectionToObjectConverter helperConverter;
+	private final ConversionService conversionService;
 
 	public ArrayToObjectConverter(ConversionService conversionService) {
-		this.helperConverter = new CollectionToObjectConverter(conversionService);
+		this.conversionService = conversionService;
 	}
 
 	public Set<ConvertiblePair> getConvertibleTypes() {
@@ -45,11 +44,21 @@ final class ArrayToObjectConverter implements ConditionalGenericConverter {
 	}
 
 	public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
-		return this.helperConverter.matches(sourceType, targetType);
+		return ConversionUtils.canConvertElements(sourceType.getElementTypeDescriptor(), targetType, conversionService);
 	}
 	
 	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
-		return this.helperConverter.convert(Arrays.asList(ObjectUtils.toObjectArray(source)), sourceType, targetType);
+		if (source == null) {
+			return null;
+		}
+		if (sourceType.isAssignableTo(targetType)) {
+			return source;
+		}
+		if (Array.getLength(source) == 0) {
+			return null;
+		}
+		Object firstElement = Array.get(source, 0);
+		return this.conversionService.convert(firstElement, sourceType.elementTypeDescriptor(firstElement), targetType);
 	}
 
 }

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

@@ -50,6 +50,9 @@ final class CollectionToObjectConverter implements ConditionalGenericConverter {
 		if (source == null) {
 			return null;
 		}
+		if (sourceType.isAssignableTo(targetType)) {
+			return source;
+		}
 		Collection<?> sourceCollection = (Collection<?>) source;
 		if (sourceCollection.size() == 0) {
 			return null;

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

@@ -388,7 +388,7 @@ public class DefaultConversionTests {
 	@Test
 	public void convertArrayToObject() {
 		Object[] array = new Object[] { 3L };
-		Object result = conversionService.convert(array, Object.class);
+		Object result = conversionService.convert(array, Long.class);
 		assertEquals(3L, result);
 	}
 
@@ -399,6 +399,13 @@ public class DefaultConversionTests {
 		assertEquals(new Integer(3), result);
 	}
 
+	@Test
+	public void convertArrayToObjectAssignableTargetType() {
+		Long[] array = new Long[] { 3L };
+		Long[] result = (Long[]) conversionService.convert(array, Object.class);
+		assertEquals(array, result);
+	}
+
 	@Test
 	public void convertObjectToArray() {
 		Object[] result = conversionService.convert(3L, Object[].class);
@@ -491,6 +498,14 @@ public class DefaultConversionTests {
 		assertEquals(new Integer(3), result);
 	}
 
+	@Test
+	public void convertCollectionToObjectAssignableTarget() throws Exception {
+		Collection<String> source = new ArrayList<String>();
+		source.add("foo");
+		Object result = conversionService.convert(source, new TypeDescriptor(getClass().getField("assignableTarget")));
+		assertEquals(source, result);
+	}
+	
 	@Test
 	public void convertObjectToCollection() {
 		List<String> result = (List<String>) conversionService.convert(3L, List.class);
@@ -671,6 +686,8 @@ public class DefaultConversionTests {
 		conversionService.convert(new Long(3), SSN.class);
 	}
 	
+	public Object assignableTarget;
+	
 	private static class SSN {
 		
 		private String value;