Fixed type prediction for generic factory methods

We're consistently resolving class names now, and the entire algorithm moved from GenericTypeResolver to the internal AutowireUtils helper in the bean factory package.

Issue: SPR-10411

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

@@ -0,0 +1,195 @@
+/*
+ * 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.
+ * 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.beans.factory.support;
+
+import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Test;
+
+import org.springframework.util.ReflectionUtils;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Juergen Hoeller
+ * @author Sam Brannen
+ */
+public class AutowireUtilsTests {
+
+	@Test
+	public void genericMethodReturnTypes() {
+		Method notParameterized = ReflectionUtils.findMethod(MyTypeWithMethods.class, "notParameterized", new Class[]{});
+		assertEquals(String.class,
+				AutowireUtils.resolveReturnTypeForFactoryMethod(notParameterized, new Object[]{}, getClass().getClassLoader()));
+
+		Method notParameterizedWithArguments = ReflectionUtils.findMethod(MyTypeWithMethods.class, "notParameterizedWithArguments",
+				new Class[] { Integer.class, Boolean.class });
+		assertEquals(String.class,
+				AutowireUtils.resolveReturnTypeForFactoryMethod(notParameterizedWithArguments, new Object[] { 99, true }, getClass().getClassLoader()));
+
+		Method createProxy = ReflectionUtils.findMethod(MyTypeWithMethods.class, "createProxy", new Class[] { Object.class });
+		assertEquals(String.class,
+				AutowireUtils.resolveReturnTypeForFactoryMethod(createProxy, new Object[] { "foo" }, getClass().getClassLoader()));
+
+		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()));
+
+		Method createNamedProxyWithDuplicateTypes = ReflectionUtils.findMethod(MyTypeWithMethods.class, "createNamedProxy",
+				new Class[] { String.class, Object.class });
+		assertEquals(String.class,
+				AutowireUtils.resolveReturnTypeForFactoryMethod(createNamedProxyWithDuplicateTypes, new Object[] { "enigma", "foo" }, getClass().getClassLoader()));
+
+		Method createMock = ReflectionUtils.findMethod(MyTypeWithMethods.class, "createMock", new Class[] { Class.class });
+		assertEquals(Runnable.class,
+				AutowireUtils.resolveReturnTypeForFactoryMethod(createMock, new Object[] { Runnable.class }, getClass().getClassLoader()));
+		assertEquals(Runnable.class,
+				AutowireUtils.resolveReturnTypeForFactoryMethod(createMock, new Object[] { Runnable.class.getName() }, getClass().getClassLoader()));
+
+		Method createNamedMock = ReflectionUtils.findMethod(MyTypeWithMethods.class, "createNamedMock", new Class[] { String.class,
+				Class.class });
+		assertEquals(Runnable.class,
+				AutowireUtils.resolveReturnTypeForFactoryMethod(createNamedMock, new Object[] { "foo", Runnable.class }, getClass().getClassLoader()));
+
+		Method createVMock = ReflectionUtils.findMethod(MyTypeWithMethods.class, "createVMock",
+				new Class[] { Object.class, Class.class });
+		assertEquals(Runnable.class,
+				AutowireUtils.resolveReturnTypeForFactoryMethod(createVMock, new Object[] { "foo", Runnable.class }, getClass().getClassLoader()));
+
+		// Ideally we would expect String.class instead of Object.class, but
+		// resolveReturnTypeForFactoryMethod() does not currently support this form of
+		// look-up.
+		Method extractValueFrom = ReflectionUtils.findMethod(MyTypeWithMethods.class, "extractValueFrom",
+				new Class[] { MyInterfaceType.class });
+		assertEquals(Object.class,
+				AutowireUtils.resolveReturnTypeForFactoryMethod(extractValueFrom, new Object[] { new MySimpleInterfaceType() }, getClass().getClassLoader()));
+
+		// Ideally we would expect Boolean.class instead of Object.class, but this
+		// information is not available at run-time due to type erasure.
+		Map<Integer, Boolean> map = new HashMap<Integer, Boolean>();
+		map.put(0, false);
+		map.put(1, true);
+		Method extractMagicValue = ReflectionUtils.findMethod(MyTypeWithMethods.class, "extractMagicValue", new Class[] { Map.class });
+		assertEquals(Object.class, AutowireUtils.resolveReturnTypeForFactoryMethod(extractMagicValue, new Object[] { map }, getClass().getClassLoader()));
+	}
+
+
+	public interface MyInterfaceType<T> {
+	}
+
+	public class MySimpleInterfaceType implements MyInterfaceType<String> {
+	}
+
+	public static class MyTypeWithMethods<T> {
+
+		public MyInterfaceType<Integer> integer() {
+			return null;
+		}
+
+		public MySimpleInterfaceType string() {
+			return null;
+		}
+
+		public Object object() {
+			return null;
+		}
+
+		@SuppressWarnings("rawtypes")
+		public MyInterfaceType raw() {
+			return null;
+		}
+
+		public String notParameterized() {
+			return null;
+		}
+
+		public String notParameterizedWithArguments(Integer x, Boolean b) {
+			return null;
+		}
+
+		/**
+		 * Simulates a factory method that wraps the supplied object in a proxy of the
+		 * same type.
+		 */
+		public static <T> T createProxy(T object) {
+			return null;
+		}
+
+		/**
+		 * Similar to {@link #createProxy(Object)} but adds an additional argument before
+		 * the argument of type {@code T}. Note that they may potentially be of the same
+		 * time when invoked!
+		 */
+		public static <T> T createNamedProxy(String name, T object) {
+			return null;
+		}
+
+		/**
+		 * Simulates factory methods found in libraries such as Mockito and EasyMock.
+		 */
+		public static <MOCK> MOCK createMock(Class<MOCK> toMock) {
+			return null;
+		}
+
+		/**
+		 * Similar to {@link #createMock(Class)} but adds an additional method argument
+		 * before the parameterized argument.
+		 */
+		public static <T> T createNamedMock(String name, Class<T> toMock) {
+			return null;
+		}
+
+		/**
+		 * Similar to {@link #createNamedMock(String, Class)} but adds an additional
+		 * parameterized type.
+		 */
+		public static <V extends Object, T> T createVMock(V name, Class<T> toMock) {
+			return null;
+		}
+
+		/**
+		 * Extract some value of the type supported by the interface (i.e., by a concrete,
+		 * non-generic implementation of the interface).
+		 */
+		public static <T> T extractValueFrom(MyInterfaceType<T> myInterfaceType) {
+			return null;
+		}
+
+		/**
+		 * Extract some magic value from the supplied map.
+		 */
+		public static <K, V> V extractMagicValue(Map<K, V> map) {
+			return null;
+		}
+
+		public void readIntegerInputMessage(MyInterfaceType<Integer> message) {
+		}
+
+		public void readIntegerArrayInputMessage(MyInterfaceType<Integer>[] message) {
+		}
+
+		public void readGenericArrayInputMessage(T[] message) {
+		}
+	}
+
+}