Revert ConversionService SPI interface

Remove canBypassConvert() methods from the ConversionService SPI
interface, restoring it to the previous Spring 3.1 incarnation.

Bypassing conversion is now only supported when using a
GenericConversionService.

Issue: SPR-9566

spring-core/src/main/java/org/springframework/core/convert/ConversionService.java

@@ -55,30 +55,6 @@ public interface ConversionService {
 	 */
 	boolean canConvert(TypeDescriptor sourceType, TypeDescriptor targetType);
 
-	/**
-	 * Returns true if conversion between the sourceType and targetType can be bypassed.
-	 * More precisely this method will return true if objects of sourceType can be
-	 * converted to the targetType by returning the source object unchanged.
-	 * @param sourceType context about the source type to convert from (may be null if source is null)
-	 * @param targetType context about the target type to convert to (required)
-	 * @return true if conversion can be bypassed
-	 * @throws IllegalArgumentException if targetType is null
-	 * @since 3.2
-	 */
-	boolean canBypassConvert(Class<?> sourceType, Class<?> targetType);
-
-	/**
-	 * Returns true if conversion between the sourceType and targetType can be bypassed.
-	 * More precisely this method will return true if objects of sourceType can be
-	 * converted to the targetType by returning the source object unchanged.
-	 * @param sourceType context about the source type to convert from (may be null if source is null)
-	 * @param targetType context about the target type to convert to (required)
-	 * @return true if conversion can be bypassed
-	 * @throws IllegalArgumentException if targetType is null
-	 * @since 3.2
-	 */
-	boolean canBypassConvert(TypeDescriptor sourceType, TypeDescriptor targetType);
-
 	/**
 	 * Convert the source to targetType.
 	 * @param source the source object to convert (may be null)

spring-core/src/main/java/org/springframework/core/convert/support/ArrayToArrayConverter.java

@@ -55,8 +55,10 @@ final class ArrayToArrayConverter implements ConditionalGenericConverter {
 
 	public Object convert(Object source, TypeDescriptor sourceType,
 			TypeDescriptor targetType) {
-		if (conversionService.canBypassConvert(sourceType.getElementTypeDescriptor(),
-				targetType.getElementTypeDescriptor())) {
+		if ((conversionService instanceof GenericConversionService)
+				&& ((GenericConversionService) conversionService).canBypassConvert(
+						sourceType.getElementTypeDescriptor(),
+						targetType.getElementTypeDescriptor())) {
 			return source;
 		}
 		List<Object> sourceList = Arrays.asList(ObjectUtils.toObjectArray(source));

spring-core/src/main/java/org/springframework/core/convert/support/GenericConversionService.java

@@ -129,13 +129,16 @@ public class GenericConversionService implements ConfigurableConversionService {
 		return (converter != null);
 	}
 
-	public boolean canBypassConvert(Class<?> sourceType, Class<?> targetType) {
-		Assert.notNull(targetType, "The targetType to convert to cannot be null");
-		return canBypassConvert(sourceType != null ?
-				TypeDescriptor.valueOf(sourceType) : null,
-				TypeDescriptor.valueOf(targetType));
-	}
-
+	/**
+	 * Returns true if conversion between the sourceType and targetType can be bypassed.
+	 * More precisely this method will return true if objects of sourceType can be
+	 * converted to the targetType by returning the source object unchanged.
+	 * @param sourceType context about the source type to convert from (may be null if source is null)
+	 * @param targetType context about the target type to convert to (required)
+	 * @return true if conversion can be bypassed
+	 * @throws IllegalArgumentException if targetType is null
+	 * @since 3.2
+	 */
 	public boolean canBypassConvert(TypeDescriptor sourceType, TypeDescriptor targetType) {
 		Assert.notNull(targetType, "The targetType to convert to cannot be null");
 		if (sourceType == null) {