Minor optimizations in factory method handling

Optimized getTypeForFactoryMethod's implementation for non-generic factory methods, and reduced calls to getResolvedFactoryMethod in order to avoid repeated synchronization. Derived from work around SPR-11034.

Author: jhoeller

spring-beans/src/main/java/org/springframework/beans/factory/annotation/QualifierAnnotationAutowireCandidateResolver.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.
@@ -233,8 +233,9 @@ protected boolean checkQualifier(
 		}
 		if (qualifier == null) {
 			Annotation targetAnnotation = null;
-			if (bd.getResolvedFactoryMethod() != null) {
-				targetAnnotation = AnnotationUtils.getAnnotation(bd.getResolvedFactoryMethod(), type);
+			Method resolvedFactoryMethod = bd.getResolvedFactoryMethod();
+			if (resolvedFactoryMethod != null) {
+				targetAnnotation = AnnotationUtils.getAnnotation(resolvedFactoryMethod, type);
 			}
 			if (targetAnnotation == null) {
 				// look for matching annotation on the target class

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractAutowireCapableBeanFactory.java

@@ -569,7 +569,7 @@ else if (!this.allowRawInjectionDespiteWrapping && hasDependentBean(beanName)) {
 	}
 
 	@Override
-	protected Class<?> predictBeanType(String beanName, RootBeanDefinition mbd, Class... typesToMatch) {
+	protected Class<?> predictBeanType(String beanName, RootBeanDefinition mbd, Class<?>... typesToMatch) {
 		Class<?> targetType = mbd.getTargetType();
 		if (targetType == null) {
 			targetType = (mbd.getFactoryMethodName() != null ? getTypeForFactoryMethod(beanName, mbd, typesToMatch) :
@@ -641,31 +641,38 @@ protected Class<?> getTypeForFactoryMethod(String beanName, RootBeanDefinition m
 			if (Modifier.isStatic(factoryMethod.getModifiers()) == isStatic &&
 					factoryMethod.getName().equals(mbd.getFactoryMethodName()) &&
 					factoryMethod.getParameterTypes().length >= minNrOfArgs) {
-				Class<?>[] paramTypes = factoryMethod.getParameterTypes();
-				String[] paramNames = null;
-				ParameterNameDiscoverer pnd = getParameterNameDiscoverer();
-				if (pnd != null) {
-					paramNames = pnd.getParameterNames(factoryMethod);
-				}
-				ConstructorArgumentValues cav = mbd.getConstructorArgumentValues();
-				Set<ConstructorArgumentValues.ValueHolder> usedValueHolders =
-						new HashSet<ConstructorArgumentValues.ValueHolder>(paramTypes.length);
-				Object[] args = new Object[paramTypes.length];
-				for (int i = 0; i < args.length; i++) {
-					ConstructorArgumentValues.ValueHolder valueHolder = cav.getArgumentValue(
-							i, paramTypes[i], (paramNames != null ? paramNames[i] : null), usedValueHolders);
-					if (valueHolder == null) {
-						valueHolder = cav.getGenericArgumentValue(null, null, usedValueHolders);
+				// No declared type variables to inspect, so just process the standard return type.
+				if (factoryMethod.getTypeParameters().length > 0) {
+					// Fully resolve parameter names and argument values.
+					Class<?>[] paramTypes = factoryMethod.getParameterTypes();
+					String[] paramNames = null;
+					ParameterNameDiscoverer pnd = getParameterNameDiscoverer();
+					if (pnd != null) {
+						paramNames = pnd.getParameterNames(factoryMethod);
 					}
-					if (valueHolder != null) {
-						args[i] = valueHolder.getValue();
-						usedValueHolders.add(valueHolder);
+					ConstructorArgumentValues cav = mbd.getConstructorArgumentValues();
+					Set<ConstructorArgumentValues.ValueHolder> usedValueHolders =
+							new HashSet<ConstructorArgumentValues.ValueHolder>(paramTypes.length);
+					Object[] args = new Object[paramTypes.length];
+					for (int i = 0; i < args.length; i++) {
+						ConstructorArgumentValues.ValueHolder valueHolder = cav.getArgumentValue(
+								i, paramTypes[i], (paramNames != null ? paramNames[i] : null), usedValueHolders);
+						if (valueHolder == null) {
+							valueHolder = cav.getGenericArgumentValue(null, null, usedValueHolders);
+						}
+						if (valueHolder != null) {
+							args[i] = valueHolder.getValue();
+							usedValueHolders.add(valueHolder);
+						}
+					}
+					Class<?> returnType = AutowireUtils.resolveReturnTypeForFactoryMethod(
+							factoryMethod, args, getBeanClassLoader());
+					if (returnType != null) {
+						returnTypes.add(returnType);
 					}
 				}
-				Class<?> returnType = AutowireUtils.resolveReturnTypeForFactoryMethod(
-						factoryMethod, args, getBeanClassLoader());
-				if (returnType != null) {
-					returnTypes.add(returnType);
+				else {
+					returnTypes.add(factoryMethod.getReturnType());
 				}
 			}
 		}

spring-beans/src/main/java/org/springframework/beans/factory/support/AutowireUtils.java

@@ -193,17 +193,7 @@ public static Class<?> resolveReturnTypeForFactoryMethod(Method method, Object[]
 		TypeVariable<Method>[] declaredTypeVariables = method.getTypeParameters();
 		Type genericReturnType = method.getGenericReturnType();
 		Type[] methodArgumentTypes = method.getGenericParameterTypes();
-
-		// No declared type variables to inspect, so just return the standard return type.
-		if (declaredTypeVariables.length == 0) {
-			return method.getReturnType();
-		}
-
-		// The supplied argument list is too short for the method's signature, so
-		// return null, since such a method invocation would fail.
-		if (args.length < methodArgumentTypes.length) {
-			return null;
-		}
+		Assert.isTrue(args.length == methodArgumentTypes.length, "Argument array does not match parameter count");
 
 		// Ensure that the type variable (e.g., T) is declared directly on the method
 		// itself (e.g., via <T>), not on the enclosing class or interface.

spring-beans/src/test/java/org/springframework/beans/factory/support/AutowireUtilsTests.java

@@ -49,9 +49,6 @@ public void genericMethodReturnTypes() {
 
 		Method createNamedProxyWithDifferentTypes = ReflectionUtils.findMethod(MyTypeWithMethods.class, "createNamedProxy",
 				new Class[] { String.class, Object.class });
-		// one argument to few
-		assertNull(
-				AutowireUtils.resolveReturnTypeForFactoryMethod(createNamedProxyWithDifferentTypes, new Object[]{"enigma"}, getClass().getClassLoader()));
 		assertEquals(Long.class,
 				AutowireUtils.resolveReturnTypeForFactoryMethod(createNamedProxyWithDifferentTypes, new Object[] { "enigma", 99L }, getClass().getClassLoader()));
 

spring-beans/src/test/java/org/springframework/beans/factory/support/BeanFactoryGenericsTests.java

@@ -654,17 +654,13 @@ public void testSetBean() throws Exception {
 	/**
 	 * Tests support for parameterized static {@code factory-method} declarations such as
 	 * Mockito's {@code mock()} method which has the following signature.
-	 * 
 	 * <pre>
 	 * {@code
 	 * public static <T> T mock(Class<T> classToMock)
 	 * }
 	 * </pre>
-	 * 
 	 * <p>
 	 * See SPR-9493
-	 * 
-	 * @since 3.2
 	 */
 	@Test
 	public void parameterizedStaticFactoryMethod() {
@@ -701,7 +697,6 @@ public void parameterizedInstanceFactoryMethod() {
 		rbd.setFactoryBeanName("mocksControl");
 		rbd.setFactoryMethodName("createMock");
 		rbd.getConstructorArgumentValues().addGenericArgumentValue(Runnable.class);
-
 		bf.registerBeanDefinition("mock", rbd);
 
 		Map<String, Runnable> beans = bf.getBeansOfType(Runnable.class);
@@ -719,7 +714,6 @@ public void parameterizedInstanceFactoryMethodWithNonResolvedClassName() {
 		rbd.setFactoryBeanName("mocksControl");
 		rbd.setFactoryMethodName("createMock");
 		rbd.getConstructorArgumentValues().addGenericArgumentValue(Runnable.class.getName());
-
 		bf.registerBeanDefinition("mock", rbd);
 
 		Map<String, Runnable> beans = bf.getBeansOfType(Runnable.class);
@@ -737,7 +731,6 @@ public void parameterizedInstanceFactoryMethodWithIndexedArgument() {
 		rbd.setFactoryBeanName("mocksControl");
 		rbd.setFactoryMethodName("createMock");
 		rbd.getConstructorArgumentValues().addIndexedArgumentValue(0, Runnable.class);
-
 		bf.registerBeanDefinition("mock", rbd);
 
 		Map<String, Runnable> beans = bf.getBeansOfType(Runnable.class);
@@ -788,21 +781,18 @@ public void setUrlNames(Set<URI> urlNames) throws MalformedURLException {
 		}
 	}
 
+
 	/**
 	 * Pseudo-implementation of EasyMock's {@code MocksControl} class.
 	 */
 	public static class MocksControl {
 
 		@SuppressWarnings("unchecked")
 		public <T> T createMock(Class<T> toMock) {
-
-			return (T) Proxy.newProxyInstance(
-					BeanFactoryGenericsTests.class.getClassLoader(),
-					new Class[] { toMock }, new InvocationHandler() {
-
+			return (T) Proxy.newProxyInstance(BeanFactoryGenericsTests.class.getClassLoader(), new Class<?>[] {toMock},
+					new InvocationHandler() {
 						@Override
-						public Object invoke(Object proxy, Method method, Object[] args)
-								throws Throwable {
+						public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
 							throw new UnsupportedOperationException("mocked!");
 						}
 					});