GenericTypeResolver works for nested parameterized types and for generic superclasses as well (SPR-7389)

org.springframework.core/src/test/java/org/springframework/core/GenericTypeResolverTests.java

@@ -0,0 +1,69 @@
+/*
+ * 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.
+ */
+
+package org.springframework.core;
+
+import java.util.Collection;
+
+import static org.junit.Assert.*;
+import org.junit.Test;
+
+/**
+ * @author Juergen Hoeller
+ */
+public class GenericTypeResolverTests {
+
+	@Test
+	public void testSimpleInterfaceType() {
+		assertEquals(String.class, GenericTypeResolver.resolveTypeArgument(MySimpleInterfaceType.class, MyInterfaceType.class));
+	}
+
+	@Test
+	public void testSimpleCollectionInterfaceType() {
+		assertEquals(Collection.class, GenericTypeResolver.resolveTypeArgument(MyCollectionInterfaceType.class, MyInterfaceType.class));
+	}
+
+	@Test
+	public void testSimpleSuperclassType() {
+		assertEquals(String.class, GenericTypeResolver.resolveTypeArgument(MySimpleSuperclassType.class, MySuperclassType.class));
+	}
+
+	@Test
+	public void testSimpleCollectionSuperclassType() {
+		assertEquals(Collection.class, GenericTypeResolver.resolveTypeArgument(MyCollectionSuperclassType.class, MySuperclassType.class));
+	}
+
+
+	public interface MyInterfaceType<T> {
+	}
+
+	public class MySimpleInterfaceType implements MyInterfaceType<String> {
+	}
+
+	public class MyCollectionInterfaceType implements MyInterfaceType<Collection<String>> {
+	}
+
+
+	public abstract class MySuperclassType<T> {
+	}
+
+	public class MySimpleSuperclassType extends MySuperclassType<String> {
+	}
+
+	public class MyCollectionSuperclassType extends MySuperclassType<Collection<String>> {
+	}
+
+}