Introduce strategy for BeanInfo creation

Before this commit, the CachedIntrospectionResults was hard-coded to
create ExtendedBeanInfos for bean classes. The ExtendedBeanInfo support
the JavaBeans property contract only.

This commit introduces the BeanInfoFactory, a strategy for creating
BeanInfos. Through this strategy, it is possible to support
beans that do not necessarily implement the JavaBeans contract (i.e.
have a different getter or setter style).

BeanInfoFactories are are instantiated by the
CachedIntrospectionResults, which looks for
'META-INF/spring.beanInfoFactories' files on the class path. These files
contain one or more BeanInfoFactory class names. When a BeanInfo is to
be created, the CachedIntrospectionResults will iterate through the
factories, asking it to create a BeanInfo for the given bean class. If
none of the factories support it, an ExtendedBeanInfo is created as a
default.

This commit also contains a change to Property, allowing BeanWrapperImpl
to specify the property name at construction time (as opposed to using
Property#resolveName(), which supports the JavaBeans contract only).

Issue: SPR-9677

spring-beans/src/test/java/org/springframework/beans/CachedIntrospectionResultsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -16,21 +16,24 @@
 
 package org.springframework.beans;
 
-import static org.junit.Assert.*;
+import java.beans.BeanInfo;
 
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 import org.junit.Test;
-import org.springframework.core.OverridingClassLoader;
-
 import test.beans.TestBean;
 
+import org.springframework.core.OverridingClassLoader;
+
 /**
  * @author Juergen Hoeller
  * @author Chris Beams
+ * @author Arjen Poutsma
  */
 public final class CachedIntrospectionResultsTests {
 
 	@Test
-	public void testAcceptClassLoader() throws Exception {
+	public void acceptClassLoader() throws Exception {
 		BeanWrapper bw = new BeanWrapperImpl(TestBean.class);
 		assertTrue(bw.isWritableProperty("name"));
 		assertTrue(bw.isWritableProperty("age"));
@@ -50,4 +53,12 @@ public final class CachedIntrospectionResultsTests {
 		assertTrue(CachedIntrospectionResults.classCache.containsKey(TestBean.class));
 	}
 
+	@Test
+	public void customBeanInfoFactory() throws Exception {
+		CachedIntrospectionResults results = CachedIntrospectionResults.forClass(CachedIntrospectionResultsTests.class);
+		BeanInfo beanInfo = results.getBeanInfo();
+
+		assertTrue("Invalid BeanInfo instance", beanInfo instanceof DummyBeanInfoFactory.DummyBeanInfo);
+	}
+
 }

spring-beans/src/test/java/org/springframework/beans/DummyBeanInfoFactory.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2002-2012 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;
+
+import java.beans.BeanInfo;
+import java.beans.PropertyDescriptor;
+import java.beans.SimpleBeanInfo;
+
+public class DummyBeanInfoFactory implements BeanInfoFactory {
+
+	public boolean supports(Class<?> beanClass) {
+		return CachedIntrospectionResultsTests.class.equals(beanClass);
+	}
+
+	public BeanInfo getBeanInfo(Class<?> beanClass) {
+		return new DummyBeanInfo();
+	}
+
+	public static class DummyBeanInfo extends SimpleBeanInfo {
+
+		@Override
+		public PropertyDescriptor[] getPropertyDescriptors() {
+			return new PropertyDescriptor[0];
+		}
+	}
+
+}