Extract SimpleBeanInfo adaptation into internal SimpleBeanInfoFactory

See gh-29320

Author: jhoeller

spring-beans/src/main/java/org/springframework/beans/CachedIntrospectionResults.java

@@ -19,12 +19,10 @@
 import java.beans.BeanInfo;
 import java.beans.IntrospectionException;
 import java.beans.PropertyDescriptor;
-import java.beans.SimpleBeanInfo;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.net.URL;
 import java.security.ProtectionDomain;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
@@ -79,12 +77,11 @@
  */
 public final class CachedIntrospectionResults {
 
-	private static final PropertyDescriptor[] EMPTY_PROPERTY_DESCRIPTOR_ARRAY = {};
-
-
 	private static final List<BeanInfoFactory> beanInfoFactories = SpringFactoriesLoader.loadFactories(
 			BeanInfoFactory.class, CachedIntrospectionResults.class.getClassLoader());
 
+	private static final SimpleBeanInfoFactory simpleBeanInfoFactory = new SimpleBeanInfoFactory();
+
 	private static final Log logger = LogFactory.getLog(CachedIntrospectionResults.class);
 
 	/**
@@ -228,14 +225,7 @@ private static BeanInfo getBeanInfo(Class<?> beanClass) throws IntrospectionExce
 				return beanInfo;
 			}
 		}
-
-		Collection<PropertyDescriptor> pds = PropertyDescriptorUtils.determineBasicProperties(beanClass);
-		return new SimpleBeanInfo() {
-			@Override
-			public PropertyDescriptor[] getPropertyDescriptors() {
-				return pds.toArray(EMPTY_PROPERTY_DESCRIPTOR_ARRAY);
-			}
-		};
+		return simpleBeanInfoFactory.getBeanInfo(beanClass);
 	}
 
 
@@ -405,7 +395,7 @@ PropertyDescriptor getPropertyDescriptor(String name) {
 	}
 
 	PropertyDescriptor[] getPropertyDescriptors() {
-		return this.propertyDescriptors.values().toArray(EMPTY_PROPERTY_DESCRIPTOR_ARRAY);
+		return this.propertyDescriptors.values().toArray(PropertyDescriptorUtils.EMPTY_PROPERTY_DESCRIPTOR_ARRAY);
 	}
 
 	private PropertyDescriptor buildGenericTypeAwarePropertyDescriptor(Class<?> beanClass, PropertyDescriptor pd) {

spring-beans/src/main/java/org/springframework/beans/PropertyDescriptorUtils.java

@@ -36,6 +36,9 @@
  */
 abstract class PropertyDescriptorUtils {
 
+	public static final PropertyDescriptor[] EMPTY_PROPERTY_DESCRIPTOR_ARRAY = {};
+
+
 	/**
 	 * Simple introspection algorithm for basic set/get/is accessor methods,
 	 * building corresponding JavaBeans property descriptors for them.
@@ -46,6 +49,7 @@ abstract class PropertyDescriptorUtils {
 	 * @return a collection of property descriptors
 	 * @throws IntrospectionException from introspecting the given bean class
 	 * @since 6.0
+	 * @see SimpleBeanInfoFactory
 	 * @see java.beans.Introspector#getBeanInfo(Class)
 	 */
 	public static Collection<PropertyDescriptor> determineBasicProperties(Class<?> beanClass) throws IntrospectionException {

spring-beans/src/main/java/org/springframework/beans/SimpleBeanInfoFactory.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2002-2022 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
+ *
+ *      https://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.IntrospectionException;
+import java.beans.PropertyDescriptor;
+import java.beans.SimpleBeanInfo;
+import java.util.Collection;
+
+import org.springframework.core.Ordered;
+import org.springframework.lang.NonNull;
+
+/**
+ * {@link BeanInfoFactory} implementation that bypasses the standard {@link java.beans.Introspector}
+ * for faster introspection, reduced to basic property determination (as commonly needed in Spring).
+ *
+ * <p>Used by default in 6.0 through direct invocation from {@link CachedIntrospectionResults}.
+ * Potentially configured via a {@code META-INF/spring.factories} file with the following content,
+ * overriding other custom {@code org.springframework.beans.BeanInfoFactory} declarations:
+ * {@code org.springframework.beans.BeanInfoFactory=org.springframework.beans.SimpleBeanInfoFactory}
+ *
+ * <p>Ordered at {@code Ordered.LOWEST_PRECEDENCE - 1} to override {@link ExtendedBeanInfoFactory}
+ * (registered by default in 5.3) if necessary while still allowing other user-defined
+ * {@link BeanInfoFactory} types to take precedence.
+ *
+ * @author Juergen Hoeller
+ * @since 6.0
+ * @see ExtendedBeanInfoFactory
+ * @see CachedIntrospectionResults
+ */
+class SimpleBeanInfoFactory implements BeanInfoFactory, Ordered {
+
+	@Override
+	@NonNull
+	public BeanInfo getBeanInfo(Class<?> beanClass) throws IntrospectionException {
+		Collection<PropertyDescriptor> pds = PropertyDescriptorUtils.determineBasicProperties(beanClass);
+		return new SimpleBeanInfo() {
+			@Override
+			public PropertyDescriptor[] getPropertyDescriptors() {
+				return pds.toArray(PropertyDescriptorUtils.EMPTY_PROPERTY_DESCRIPTOR_ARRAY);
+			}
+		};
+	}
+
+	@Override
+	public int getOrder() {
+		return Ordered.LOWEST_PRECEDENCE - 1;
+	}
+
+}