| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.axis2.classloader; |
| |
| import java.beans.BeanInfo; |
| import java.beans.IntrospectionException; |
| import java.beans.Introspector; |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| /** |
| * {@link BeanInfo} cache that stores introspection results by bean class and stop class. This goes |
| * beyond the caching provided by the JRE, which only caches the results of |
| * {@link Introspector#getBeanInfo(Class)}, but not the results of |
| * {@link Introspector#getBeanInfo(Class, Class)} (with non null stop class). |
| * <p> |
| * To avoid class loader leaks, this class should not be used as a singleton if the introspected |
| * classes are loaded from class loaders that are children of the class loader which holds the |
| * reference to the cache. In such scenarios, use {@link #getCachedBeanInfo(Class, Class)}. |
| */ |
| public final class BeanInfoCache { |
| private static final class CacheKey { |
| private final Class<?> beanClass; |
| private final Class<?> stopClass; |
| |
| CacheKey(Class<?> beanClass, Class<?> stopClass) { |
| this.beanClass = beanClass; |
| this.stopClass = stopClass; |
| } |
| |
| @Override |
| public int hashCode() { |
| return 31*beanClass.hashCode() + (stopClass == null ? 0 : stopClass.hashCode()); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj instanceof CacheKey) { |
| CacheKey other = (CacheKey)obj; |
| return beanClass == other.beanClass && stopClass == other.stopClass; |
| } else { |
| return false; |
| } |
| } |
| } |
| |
| private static final Log log = LogFactory.getLog(BeanInfoCache.class); |
| |
| /** |
| * Local cache instance for Javabeans that are loaded from the same class loader as this class. |
| */ |
| private static final BeanInfoCache localCache = new BeanInfoCache(); |
| |
| private final Map<CacheKey,BeanInfo> cache = new ConcurrentHashMap<CacheKey,BeanInfo>(); |
| |
| /** |
| * Introspect on a Java bean and return a cached {@link BeanInfo} object. |
| * |
| * @param beanClass |
| * The bean class to be analyzed. |
| * @param stopClass |
| * The base class at which to stop the analysis; may be <code>null</code>. |
| * @return A {@link BeanInfo} object describing the target bean. |
| * @exception IntrospectionException |
| * if an exception occurs during introspection. |
| * @see Introspector#getBeanInfo(Class, Class) |
| */ |
| public BeanInfo getBeanInfo(Class<?> beanClass, Class<?> stopClass) throws IntrospectionException { |
| CacheKey key = new CacheKey(beanClass, stopClass); |
| BeanInfo beanInfo = cache.get(key); |
| if (beanInfo == null) { |
| beanInfo = Introspector.getBeanInfo(beanClass, stopClass); |
| cache.put(key, beanInfo); |
| } |
| return beanInfo; |
| } |
| |
| /** |
| * Locate an appropriate {@link BeanInfoCache} and return a cached {@link BeanInfo} object. |
| * This method ensures that caching the {@link BeanInfo} object will not result in a class |
| * loader leak. |
| * |
| * @param beanClass |
| * The bean class to be analyzed. |
| * @param stopClass |
| * The base class at which to stop the analysis; may be <code>null</code>. |
| * @return A {@link BeanInfo} object describing the target bean. |
| * @exception IntrospectionException |
| * if an exception occurs during introspection. |
| */ |
| public static BeanInfo getCachedBeanInfo(Class<?> beanClass, Class<?> stopClass) throws IntrospectionException { |
| ClassLoader classLoader = beanClass.getClassLoader(); |
| BeanInfoCache cache; |
| if (classLoader instanceof BeanInfoCachingClassLoader) { |
| cache = ((BeanInfoCachingClassLoader)classLoader).getBeanInfoCache(); |
| } else if (classLoader == BeanInfoCache.class.getClassLoader()) { |
| cache = localCache; |
| } else { |
| cache = null; |
| } |
| if (cache != null) { |
| return cache.getBeanInfo(beanClass, stopClass); |
| } else { |
| if (log.isWarnEnabled()) { |
| log.warn("Unable to locate a BeanInfo cache for " + beanClass + " (stopClass=" + stopClass |
| + "). This will negatively affect performance!"); |
| } |
| return Introspector.getBeanInfo(beanClass, stopClass); |
| } |
| } |
| } |