recursive mapping support

org.springframework.context/src/main/java/org/springframework/mapping/MappingFailure.java

@@ -17,6 +17,7 @@ package org.springframework.mapping;
 
 /**
  * Indicates an individual mapping failed.
+ * TODO - other fields required here?
  * @author Keith Donald
  */
 public class MappingFailure {

org.springframework.context/src/main/java/org/springframework/mapping/support/DefaultMapperTargetFactory.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2002-2009 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.mapping.support;
+
+import org.springframework.beans.BeanUtils;
+import org.springframework.core.convert.TypeDescriptor;
+
+/**
+ * Creates a mapping target by calling its default constructor.
+ * @author Keith Donald
+ * @see BeanUtils#instantiate(Class)
+ */
+class DefaultMapperTargetFactory implements MapperTargetFactory {
+
+	public Object createTarget(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
+		return BeanUtils.instantiate(targetType.getType());
+	}
+
+}

org.springframework.context/src/main/java/org/springframework/mapping/support/MapperConverter.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2002-2009 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.mapping.support;
+
+import org.springframework.core.convert.TypeDescriptor;
+import org.springframework.core.convert.support.GenericConverter;
+import org.springframework.mapping.Mapper;
+
+/**
+ * Adapts a Mapper to a Converter, allowing the conversion between two object types to be completed by a Mapper.
+ * Delegates to a {@link MapperTargetFactory} to construct the conversion target object that will be mapped.
+ * The default MapperTargetFactory instantiates a target by calling its default constructor.
+ * @author Keith Donald
+ */
+public class MapperConverter implements GenericConverter {
+
+	private Mapper mapper;
+
+	private MapperTargetFactory mappingTargetFactory;
+
+	public MapperConverter(Mapper mapper) {
+		this(mapper, new DefaultMapperTargetFactory());
+	}
+
+	public MapperConverter(Mapper mapper, MapperTargetFactory mappingTargetFactory) {
+		this.mapper = mapper;
+		this.mappingTargetFactory = mappingTargetFactory;
+	}
+
+	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
+		if (source == null) {
+			return null;
+		}
+		Object target = this.mappingTargetFactory.createTarget(source, sourceType, targetType);
+		return this.mapper.map(source, target);
+	}
+
+}

org.springframework.context/src/main/java/org/springframework/mapping/support/MapperTargetFactory.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2002-2009 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.mapping.support;
+
+import org.springframework.core.convert.TypeDescriptor;
+import org.springframework.mapping.Mapper;
+
+/**
+ * A factory for customizing how the target of a map operation is constructed.
+ * Used by a {@link MapperConverter} when executing a type conversion.
+ * @author Keith Donald
+ * @see MapperConverter
+ * @see Mapper#map(Object, Object)
+ */
+public interface MapperTargetFactory {
+
+	/**
+	 * Create the target object to be mapped to.
+	 * @param source the source object to map from
+	 * @param sourceType the source object type descriptor
+	 * @param targetType the target object type descriptor
+	 * @return the target
+	 */
+	public Object createTarget(Object source, TypeDescriptor sourceType, TypeDescriptor targetType);
+}

org.springframework.context/src/main/java/org/springframework/mapping/support/Mapping.java

@@ -26,6 +26,10 @@ import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.Expression;
 import org.springframework.mapping.MappingFailure;
 
+/**
+ * An individual mapping definition between two fields.
+ * @author Keith Donald
+ */
 class Mapping implements MappingConfiguration {
 
 	private Expression source;

org.springframework.context/src/main/java/org/springframework/mapping/support/SpelMapper.java

@@ -22,8 +22,12 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import org.springframework.core.convert.ConversionService;
+import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.core.convert.converter.ConverterRegistry;
 import org.springframework.core.convert.support.DefaultConversionService;
+import org.springframework.core.convert.support.GenericConversionService;
+import org.springframework.core.convert.support.GenericConverter;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.EvaluationException;
 import org.springframework.expression.Expression;
@@ -55,12 +59,16 @@ public class SpelMapper implements Mapper<Object, Object> {
 
 	private boolean autoMappingEnabled = true;
 
-	private final DefaultConversionService conversionService = new DefaultConversionService();
+	private MappingConversionService conversionService = new MappingConversionService();
 
 	public void setAutoMappingEnabled(boolean autoMappingEnabled) {
 		this.autoMappingEnabled = autoMappingEnabled;
 	}
 
+	public void setConversionService(ConversionService conversionService) {
+		this.conversionService.setParent(conversionService);
+	}
+
 	public MappingConfiguration addMapping(String fieldExpression) {
 		return addMapping(fieldExpression, fieldExpression);
 	}
@@ -158,6 +166,20 @@ public class SpelMapper implements Mapper<Object, Object> {
 		return false;
 	}
 
+	private class MappingConversionService extends GenericConversionService {
+
+		public MappingConversionService() {
+			setParent(new DefaultConversionService());
+		}
+
+		@Override
+		protected GenericConverter getConverter(TypeDescriptor sourceType, TypeDescriptor targetType) {
+			GenericConverter converter = super.getConverter(sourceType, targetType);
+			return converter != null ? converter : new MapperConverter(new SpelMapper());
+		}
+
+	}
+
 	private static class MappableTypeFactory {
 
 		private static final MapMappableType MAP_MAPPABLE_TYPE = new MapMappableType();
@@ -173,4 +195,5 @@ public class SpelMapper implements Mapper<Object, Object> {
 			}
 		}
 	}
+
 }

org.springframework.context/src/test/java/org/springframework/mapping/support/SpelMapperTests.java

@@ -142,11 +142,7 @@ public class SpelMapperTests {
 
 		mapper.addMapping("fullName", "name");
 		mapper.addMapping("sport", "favoriteSport");
-		mapper.addMapping("nested", "nested").setConverter(new Converter<NestedDto, Nested>() {
-			public Nested convert(NestedDto source) {
-				return (Nested) new SpelMapper().map(source, new Nested());
-			}
-		});
+		mapper.addMapping("nested", "nested");
 		mapper.map(source, target);
 
 		assertEquals("Keith Donald", target.name);