BeanWrapper/DataBinder's "autoGrowNestedPaths" works for Maps as well (SPR-7285)

org.springframework.beans/src/main/java/org/springframework/beans/BeanWrapperImpl.java

@@ -596,7 +596,7 @@ public class BeanWrapperImpl extends AbstractPropertyAccessor implements BeanWra
 	}
 	
 	private PropertyValue createDefaultPropertyValue(PropertyTokenHolder tokens) {
-		PropertyDescriptor pd = getCachedIntrospectionResults().getPropertyDescriptor(tokens.actualName);		
+		PropertyDescriptor pd = getCachedIntrospectionResults().getPropertyDescriptor(tokens.actualName);
 		Object defaultValue = newValue(pd.getPropertyType(), tokens.canonicalName);
 		return new PropertyValue(tokens.canonicalName, defaultValue);
 	}
@@ -615,13 +615,14 @@ public class BeanWrapperImpl extends AbstractPropertyAccessor implements BeanWra
 					return Array.newInstance(componentType, 0);
 				}
 			}
+			else if (Collection.class.isAssignableFrom(type)) {
+				return CollectionFactory.createCollection(type, 16);
+			}
+			else if (Map.class.isAssignableFrom(type)) {
+				return CollectionFactory.createMap(type, 16);
+			}
 			else {
-				if (Collection.class.isAssignableFrom(type)) {
-					return CollectionFactory.createCollection(type, 16);
-				}
-				else {
-					return type.newInstance();
-				}
+				return type.newInstance();
 			}
 		}
 		catch (Exception ex) {
@@ -791,6 +792,7 @@ public class BeanWrapperImpl extends AbstractPropertyAccessor implements BeanWra
 						Object convertedMapKey = convertIfNecessary(null, null, key, mapKeyType);
 						// Pass full property name and old value in here, since we want full
 						// conversion ability for map values.
+						growMapIfNecessary(map, convertedMapKey, indexedPropertyName, pd, i + 1);
 						value = map.get(convertedMapKey);
 					}
 					else {
@@ -844,7 +846,7 @@ public class BeanWrapperImpl extends AbstractPropertyAccessor implements BeanWra
 			return array;
 		}
 	}
-	
+
 	@SuppressWarnings("unchecked")
 	private void growCollectionIfNecessary(
 			Collection collection, int index, String name, PropertyDescriptor pd, int nestingLevel) {
@@ -861,7 +863,22 @@ public class BeanWrapperImpl extends AbstractPropertyAccessor implements BeanWra
 			}
 		}
 	}
-	
+
+	@SuppressWarnings("unchecked")
+	private void growMapIfNecessary(
+			Map map, Object key, String name, PropertyDescriptor pd, int nestingLevel) {
+
+		if (!this.autoGrowNestedPaths) {
+			return;
+		}
+		if (!map.containsKey(key)) {
+			Class valueType = GenericCollectionTypeResolver.getMapValueReturnType(pd.getReadMethod(), nestingLevel);
+			if (valueType != null) {
+				map.put(key, newValue(valueType, name));
+			}
+		}
+	}
+
 	@Override
 	public void setPropertyValue(String propertyName, Object value) throws BeansException {
 		BeanWrapperImpl nestedBw;

org.springframework.beans/src/test/java/org/springframework/beans/BeanWrapperAutoGrowingTests.java

@@ -1,15 +1,32 @@
-package org.springframework.beans;
+/*
+ * Copyright 2002-2010 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.
+ */
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
+package org.springframework.beans;
 
 import java.util.List;
+import java.util.Map;
 
+import static org.junit.Assert.*;
 import org.junit.Before;
 import org.junit.Test;
 
+/**
+ * @author Keith Donald
+ * @author Juergen Hoeller
+ */
 public class BeanWrapperAutoGrowingTests {
 
 	Bean bean = new Bean();
@@ -112,6 +129,20 @@ public class BeanWrapperAutoGrowingTests {
 		wrapper.getPropertyValue("listNotParameterized[0]");
 	}
 
+	@Test
+	public void getPropertyValueAutoGrowMap() {
+		assertNotNull(wrapper.getPropertyValue("map[A]"));
+		assertEquals(1, bean.getMap().size());
+		assertTrue(bean.getMap().get("A") instanceof Bean);
+	}
+
+	@Test
+	public void setPropertyValueAutoGrowMap() {
+		wrapper.setPropertyValue("map[A].prop", "test");
+		assertEquals("test", bean.getMap().get("A").getProp());
+	}
+
+
 	public static class Bean {
 
 		private String prop;
@@ -130,6 +161,8 @@ public class BeanWrapperAutoGrowingTests {
 
 		private List listNotParameterized;
 
+		private Map<String, Bean> map;
+
 		public String getProp() {
 			return prop;
 		}
@@ -182,8 +215,7 @@ public class BeanWrapperAutoGrowingTests {
 			return nestedNoConstructor;
 		}
 
-		public void setNestedNoConstructor(
-				NestedNoDefaultConstructor nestedNoConstructor) {
+		public void setNestedNoConstructor(NestedNoDefaultConstructor nestedNoConstructor) {
 			this.nestedNoConstructor = nestedNoConstructor;
 		}
 
@@ -195,11 +227,20 @@ public class BeanWrapperAutoGrowingTests {
 			this.listNotParameterized = listNotParameterized;
 		}
 
+		public Map<String, Bean> getMap() {
+			return map;
+		}
+
+		public void setMap(Map<String, Bean> map) {
+			this.map = map;
+		}
 	}
 
+
 	public static class NestedNoDefaultConstructor {
-		private NestedNoDefaultConstructor() {
 
+		private NestedNoDefaultConstructor() {
 		}
 	}
+
 }