GenericTypeResolver defensively calls Class.getGenericSuperclass() and consistently uses Class<?>

Issue: SPR-10559

Author: jhoeller

spring-context/src/main/java/org/springframework/context/event/GenericApplicationListenerAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -54,9 +54,9 @@ public void onApplicationEvent(ApplicationEvent event) {
 
 	@Override
 	public boolean supportsEventType(Class<? extends ApplicationEvent> eventType) {
-		Class typeArg = GenericTypeResolver.resolveTypeArgument(this.delegate.getClass(), ApplicationListener.class);
+		Class<?> typeArg = GenericTypeResolver.resolveTypeArgument(this.delegate.getClass(), ApplicationListener.class);
 		if (typeArg == null || typeArg.equals(ApplicationEvent.class)) {
-			Class targetClass = AopUtils.getTargetClass(this.delegate);
+			Class<?> targetClass = AopUtils.getTargetClass(this.delegate);
 			if (targetClass != this.delegate.getClass()) {
 				typeArg = GenericTypeResolver.resolveTypeArgument(targetClass, ApplicationListener.class);
 			}

spring-core/src/main/java/org/springframework/core/GenericCollectionTypeResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -19,6 +19,7 @@
 import java.lang.reflect.Array;
 import java.lang.reflect.Field;
 import java.lang.reflect.GenericArrayType;
+import java.lang.reflect.MalformedParameterizedTypeException;
 import java.lang.reflect.Method;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
@@ -446,8 +447,13 @@ private static Class<?> extractTypeFromClass(Class<?> clazz, Class<?> source, in
 			return null;
 		}
 		if (clazz.getSuperclass() != null && isIntrospectionCandidate(clazz.getSuperclass())) {
-			return extractType(clazz.getGenericSuperclass(), source, typeIndex, typeVariableMap, typeIndexesPerLevel,
-					nestingLevel, currentLevel);
+			try {
+				return extractType(clazz.getGenericSuperclass(), source, typeIndex, typeVariableMap,
+						typeIndexesPerLevel, nestingLevel, currentLevel);
+			}
+			catch (MalformedParameterizedTypeException ex) {
+				// from getGenericSuperclass() - ignore and continue with interface introspection
+			}
 		}
 		Type[] ifcs = clazz.getGenericInterfaces();
 		if (ifcs != null) {

spring-core/src/main/java/org/springframework/core/GenericTypeResolver.java

@@ -18,6 +18,7 @@
 
 import java.lang.reflect.Array;
 import java.lang.reflect.GenericArrayType;
+import java.lang.reflect.MalformedParameterizedTypeException;
 import java.lang.reflect.Method;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
@@ -74,12 +75,12 @@ public static Type getTargetType(MethodParameter methodParam) {
 	 * @param clazz the class to resolve type variables against
 	 * @return the corresponding generic parameter or return type
 	 */
-	public static Class<?> resolveParameterType(MethodParameter methodParam, Class clazz) {
+	public static Class<?> resolveParameterType(MethodParameter methodParam, Class<?> clazz) {
 		Type genericType = getTargetType(methodParam);
 		Assert.notNull(clazz, "Class must not be null");
 		Map<TypeVariable, Type> typeVariableMap = getTypeVariableMap(clazz);
 		Type rawType = getRawType(genericType, typeVariableMap);
-		Class result = (rawType instanceof Class ? (Class) rawType : methodParam.getParameterType());
+		Class<?> result = (rawType instanceof Class ? (Class) rawType : methodParam.getParameterType());
 		methodParam.setParameterType(result);
 		methodParam.typeVariableMap = typeVariableMap;
 		return result;
@@ -227,7 +228,7 @@ public static Class<?> resolveReturnTypeArgument(Method method, Class<?> generic
 	 * @param genericIfc the generic interface or superclass to resolve the type argument from
 	 * @return the resolved type of the argument, or {@code null} if not resolvable
 	 */
-	public static Class<?> resolveTypeArgument(Class clazz, Class genericIfc) {
+	public static Class<?> resolveTypeArgument(Class<?> clazz, Class<?> genericIfc) {
 		Class[] typeArgs = resolveTypeArguments(clazz, genericIfc);
 		if (typeArgs == null) {
 			return null;
@@ -248,11 +249,11 @@ public static Class<?> resolveTypeArgument(Class clazz, Class genericIfc) {
 	 * @return the resolved type of each argument, with the array size matching the
 	 * number of actual type arguments, or {@code null} if not resolvable
 	 */
-	public static Class[] resolveTypeArguments(Class clazz, Class genericIfc) {
+	public static Class[] resolveTypeArguments(Class<?> clazz, Class<?> genericIfc) {
 		return doResolveTypeArguments(clazz, clazz, genericIfc);
 	}
 
-	private static Class[] doResolveTypeArguments(Class ownerClass, Class classToIntrospect, Class genericIfc) {
+	private static Class[] doResolveTypeArguments(Class<?> ownerClass, Class<?> classToIntrospect, Class<?> genericIfc) {
 		while (classToIntrospect != null) {
 			if (genericIfc.isInterface()) {
 				Type[] ifcs = classToIntrospect.getGenericInterfaces();
@@ -264,18 +265,23 @@ private static Class[] doResolveTypeArguments(Class ownerClass, Class classToInt
 				}
 			}
 			else {
-				Class[] result = doResolveTypeArguments(
-						ownerClass, classToIntrospect.getGenericSuperclass(), genericIfc);
-				if (result != null) {
-					return result;
+				try {
+					Class[] result = doResolveTypeArguments(ownerClass, classToIntrospect.getGenericSuperclass(), genericIfc);
+					if (result != null) {
+						return result;
+					}
+				}
+				catch (MalformedParameterizedTypeException ex) {
+					// from getGenericSuperclass() - return null to skip further superclass traversal
+					return null;
 				}
 			}
 			classToIntrospect = classToIntrospect.getSuperclass();
 		}
 		return null;
 	}
 
-	private static Class[] doResolveTypeArguments(Class ownerClass, Type ifc, Class genericIfc) {
+	private static Class[] doResolveTypeArguments(Class<?> ownerClass, Type ifc, Class<?> genericIfc) {
 		if (ifc instanceof ParameterizedType) {
 			ParameterizedType paramIfc = (ParameterizedType) ifc;
 			Type rawType = paramIfc.getRawType();
@@ -301,7 +307,7 @@ else if (ifc != null && genericIfc.isAssignableFrom((Class) ifc)) {
 	/**
 	 * Extract a class instance from given Type.
 	 */
-	private static Class extractClass(Class ownerClass, Type arg) {
+	private static Class<?> extractClass(Class<?> ownerClass, Type arg) {
 		if (arg instanceof ParameterizedType) {
 			return extractClass(ownerClass, ((ParameterizedType) arg).getRawType());
 		}
@@ -368,7 +374,7 @@ static Type getRawType(Type genericType, Map<TypeVariable, Type> typeVariableMap
 	 * {@link Class concrete classes} for the specified {@link Class}. Searches
 	 * all super types, enclosing types and interfaces.
 	 */
-	public static Map<TypeVariable, Type> getTypeVariableMap(Class clazz) {
+	public static Map<TypeVariable, Type> getTypeVariableMap(Class<?> clazz) {
 		Map<TypeVariable, Type> typeVariableMap = typeVariableCache.get(clazz);
 
 		if (typeVariableMap == null) {
@@ -377,28 +383,37 @@ public static Map<TypeVariable, Type> getTypeVariableMap(Class clazz) {
 			// interfaces
 			extractTypeVariablesFromGenericInterfaces(clazz.getGenericInterfaces(), typeVariableMap);
 
-			// super class
-			Type genericType = clazz.getGenericSuperclass();
-			Class type = clazz.getSuperclass();
-			while (type != null && !Object.class.equals(type)) {
-				if (genericType instanceof ParameterizedType) {
-					ParameterizedType pt = (ParameterizedType) genericType;
-					populateTypeMapFromParameterizedType(pt, typeVariableMap);
+			try {
+				// super class
+				Class<?> type = clazz;
+				while (type.getSuperclass() != null && !Object.class.equals(type.getSuperclass())) {
+					Type genericType = type.getGenericSuperclass();
+					if (genericType instanceof ParameterizedType) {
+						ParameterizedType pt = (ParameterizedType) genericType;
+						populateTypeMapFromParameterizedType(pt, typeVariableMap);
+					}
+					extractTypeVariablesFromGenericInterfaces(type.getSuperclass().getGenericInterfaces(), typeVariableMap);
+					type = type.getSuperclass();
 				}
-				extractTypeVariablesFromGenericInterfaces(type.getGenericInterfaces(), typeVariableMap);
-				genericType = type.getGenericSuperclass();
-				type = type.getSuperclass();
+			}
+			catch (MalformedParameterizedTypeException ex) {
+				// from getGenericSuperclass() - ignore and continue with member class check
 			}
 
-			// enclosing class
-			type = clazz;
-			while (type.isMemberClass()) {
-				genericType = type.getGenericSuperclass();
-				if (genericType instanceof ParameterizedType) {
-					ParameterizedType pt = (ParameterizedType) genericType;
-					populateTypeMapFromParameterizedType(pt, typeVariableMap);
+			try {
+				// enclosing class
+				Class<?> type = clazz;
+				while (type.isMemberClass()) {
+					Type genericType = type.getGenericSuperclass();
+					if (genericType instanceof ParameterizedType) {
+						ParameterizedType pt = (ParameterizedType) genericType;
+						populateTypeMapFromParameterizedType(pt, typeVariableMap);
+					}
+					type = type.getEnclosingClass();
 				}
-				type = type.getEnclosingClass();
+			}
+			catch (MalformedParameterizedTypeException ex) {
+				// from getGenericSuperclass() - ignore and preserve previously accumulated type variables
 			}
 
 			typeVariableCache.put(clazz, typeVariableMap);

spring-core/src/main/java/org/springframework/core/ParameterizedTypeReference.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -24,7 +24,7 @@
 /**
  * The purpose of this class is to enable capturing and passing a generic
  * {@link Type}. In order to capture the generic type and retain it at runtime,
- * you need to create a sub-class as follows:
+ * you need to create a subclass as follows:
  *
  * <pre class="code">
  * ParameterizedTypeReference&lt;List&lt;String&gt;&gt; typeRef = new ParameterizedTypeReference&lt;List&lt;String&gt;&gt;() {};
@@ -37,54 +37,31 @@
  * @author Arjen Poutsma
  * @author Rossen Stoyanchev
  * @since 3.2
- *
  * @see <a href="http://gafter.blogspot.nl/2006/12/super-type-tokens.html">Neal Gafter on Super Type Tokens</a>
  */
 public abstract class ParameterizedTypeReference<T> {
 
 	private final Type type;
 
-	protected ParameterizedTypeReference() {
-		Class<?> parameterizedTypeReferenceSubClass = findParameterizedTypeReferenceSubClass(getClass());
 
-		Type type = parameterizedTypeReferenceSubClass.getGenericSuperclass();
+	protected ParameterizedTypeReference() {
+		Class<?> parameterizedTypeReferenceSubclass = findParameterizedTypeReferenceSubclass(getClass());
+		Type type = parameterizedTypeReferenceSubclass.getGenericSuperclass();
 		Assert.isInstanceOf(ParameterizedType.class, type);
-
 		ParameterizedType parameterizedType = (ParameterizedType) type;
 		Assert.isTrue(parameterizedType.getActualTypeArguments().length == 1);
-
 		this.type = parameterizedType.getActualTypeArguments()[0];
 	}
 
-	private static Class<?> findParameterizedTypeReferenceSubClass(Class<?> child) {
-
-		Class<?> parent = child.getSuperclass();
-
-		if (Object.class.equals(parent)) {
-			throw new IllegalStateException("Expected ParameterizedTypeReference superclass");
-		}
-		else if (ParameterizedTypeReference.class.equals(parent)) {
-			return child;
-		}
-		else {
-			return findParameterizedTypeReferenceSubClass(parent);
-		}
-	}
 
 	public Type getType() {
 		return this.type;
 	}
 
 	@Override
-	public boolean equals(Object o) {
-		if (this == o) {
-			return true;
-		}
-		if (o instanceof ParameterizedTypeReference) {
-			ParameterizedTypeReference<?> other = (ParameterizedTypeReference<?>) o;
-			return this.type.equals(other.type);
-		}
-		return false;
+	public boolean equals(Object obj) {
+		return (this == obj || (obj instanceof ParameterizedTypeReference &&
+				this.type.equals(((ParameterizedTypeReference) obj).type)));
 	}
 
 	@Override
@@ -96,4 +73,19 @@ public int hashCode() {
 	public String toString() {
 		return "ParameterizedTypeReference<" + this.type + ">";
 	}
+
+
+	private static Class<?> findParameterizedTypeReferenceSubclass(Class<?> child) {
+		Class<?> parent = child.getSuperclass();
+		if (Object.class.equals(parent)) {
+			throw new IllegalStateException("Expected ParameterizedTypeReference superclass");
+		}
+		else if (ParameterizedTypeReference.class.equals(parent)) {
+			return child;
+		}
+		else {
+			return findParameterizedTypeReferenceSubclass(parent);
+		}
+	}
+
 }

spring-core/src/test/java/org/springframework/core/ParameterizedTypeReferenceTest.java renamed to spring-core/src/test/java/org/springframework/core/ParameterizedTypeReferenceTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -20,16 +20,17 @@
 import java.util.List;
 import java.util.Map;
 
-import static org.junit.Assert.assertEquals;
 import org.junit.Test;
 
+import static org.junit.Assert.*;
+
 /**
  * Test fixture for {@link ParameterizedTypeReference}.
  *
  * @author Arjen Poutsma
  * @author Rossen Stoyanchev
  */
-public class ParameterizedTypeReferenceTest {
+public class ParameterizedTypeReferenceTests {
 
 	@Test
 	public void map() throws NoSuchMethodException {
@@ -58,4 +59,5 @@ public static Map<Object, String> mapMethod() {
 	public static List<String> listMethod() {
 		return null;
 	}
+
 }