added TypeDescriptor resolveCollectionElement and Map key/value types

org.springframework.expression/src/main/java/org/springframework/expression/TypedValue.java

@@ -16,6 +16,9 @@
 
 package org.springframework.expression;
 
+import java.util.Collection;
+import java.util.Map;
+
 import org.springframework.core.convert.TypeDescriptor;
 
 /**
@@ -31,12 +34,10 @@ public class TypedValue {
 
 	public static final TypedValue NULL = new TypedValue(null);
 
-
 	private final Object value;
 
 	private TypeDescriptor typeDescriptor;
 
-
 	/**
 	 * Create a TypedValue for a simple object. The type descriptor is inferred
 	 * from the object, so no generic information is preserved.
@@ -44,7 +45,8 @@ public class TypedValue {
 	 */
 	public TypedValue(Object value) {
 		this.value = value;
-		this.typeDescriptor = null;  // initialized when/if requested
+		// initialized when/if requested		
+		this.typeDescriptor = null;
 	}
 
 	/**
@@ -54,10 +56,9 @@ public class TypedValue {
 	 */
 	public TypedValue(Object value, TypeDescriptor typeDescriptor) {
 		this.value = value;
-		this.typeDescriptor = typeDescriptor;
+		this.typeDescriptor = initTypeDescriptor(value, typeDescriptor);
 	}
 	
-
 	public Object getValue() {
 		return this.value;
 	}
@@ -69,12 +70,27 @@ public class TypedValue {
 		return this.typeDescriptor;
 	}
 
-
 	@Override
 	public String toString() {
 		StringBuilder str = new StringBuilder();
 		str.append("TypedValue: '").append(this.value).append("' of [").append(getTypeDescriptor() + "]");
 		return str.toString();
 	}
+	
+	// interal helpers
 
+	private static TypeDescriptor initTypeDescriptor(Object value, TypeDescriptor typeDescriptor) {
+		if (value == null) {
+			return typeDescriptor;
+		}
+		if (typeDescriptor.isCollection() && Object.class.equals(typeDescriptor.getElementType())) {
+			return typeDescriptor.resolveCollectionElementType((Collection<?>) value);
+		} else if (typeDescriptor.isMap() && Object.class.equals(typeDescriptor.getMapKeyType())
+				&& Object.class.equals(typeDescriptor.getMapValueType())){
+			return typeDescriptor.resolveMapKeyValueTypes((Map<?, ?>) value);
+		} else {
+			return typeDescriptor;
+		}		
+	}
+	
 }

org.springframework.expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java

@@ -90,13 +90,9 @@ public class Indexer extends SpelNodeImpl {
 
 		// Indexing into a Map
 		if (targetObject instanceof Map) {
-			if (targetObjectTypeDescriptor.isMap()) {
-				Object possiblyConvertedKey = state.convertValue(index, targetObjectTypeDescriptor.getMapKeyTypeDescriptor());
-				Object o = ((Map<?, ?>) targetObject).get(possiblyConvertedKey);
-				return new TypedValue(o, targetObjectTypeDescriptor.getMapValueTypeDescriptor());
-			} else {
-				return new TypedValue(((Map<?, ?>) targetObject).get(index));				
-			}
+			Object possiblyConvertedKey = state.convertValue(index, targetObjectTypeDescriptor.getMapKeyTypeDescriptor());
+			Object o = ((Map<?, ?>) targetObject).get(possiblyConvertedKey);
+			return new TypedValue(o, targetObjectTypeDescriptor.getMapValueTypeDescriptor());
 		}
 		
 		if (targetObject == null) {