/*
* 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.wicket.spring.injection.annot;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.wicket.injection.IFieldValueFactory;
import org.apache.wicket.proxy.LazyInitProxyFactory;
import org.apache.wicket.spring.ISpringContextLocator;
import org.apache.wicket.spring.SpringBeanLocator;
import org.apache.wicket.util.lang.Generics;
import org.apache.wicket.util.string.Strings;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
/**
* {@link IFieldValueFactory} that uses {@link LazyInitProxyFactory} to create proxies for Spring
* dependencies based on the {@link SpringBean} annotation applied to a field. This class is usually
* used by the {@link AnnotSpringInjector} to inject objects with lazy init proxies. However, this
* class can be used on its own to create proxies for any field decorated with a {@link SpringBean}
* annotation.
* <p>
* Example:
*
* <pre>
* IFieldValueFactory factory = new AnnotProxyFieldValueFactory(contextLocator);
* field = obj.getClass().getDeclaredField("dependency");
* IDependency dependency = (IDependency)factory.getFieldValue(field, obj);
* </pre>
*
* In the example above the
*
* <code>dependency</code> object returned is a lazy init proxy that will look up the actual
* IDependency bean from spring context upon first access to one of the methods.
* <p>
* This class will also cache any produced proxies so that the same proxy is always returned for the
* same spring dependency. This helps cut down on session size beacause proxies for the same
* dependency will not be serialized twice.
*
* @see LazyInitProxyFactory
* @see SpringBean
* @see SpringBeanLocator
*
* @author Igor Vaynberg (ivaynberg)
* @author Istvan Devai
*
*/
public class AnnotProxyFieldValueFactory implements IFieldValueFactory
{
private final ISpringContextLocator contextLocator;
private final ConcurrentHashMap<SpringBeanLocator, Object> cache = Generics
.newConcurrentHashMap();
private final ConcurrentHashMap<Class< ? >, String> beanNameCache = Generics
.newConcurrentHashMap();
private final boolean wrapInProxies;
/**
* @param contextLocator
* spring context locator
*/
public AnnotProxyFieldValueFactory(ISpringContextLocator contextLocator)
{
this(contextLocator, true);
}
/**
* @param contextLocator
* spring context locator
* @param wrapInProxies
* whether or not wicket should wrap dependencies with specialized proxies that can
* be safely serialized. in most cases this should be set to true.
*/
public AnnotProxyFieldValueFactory(ISpringContextLocator contextLocator, boolean wrapInProxies)
{
if (contextLocator == null)
{
throw new IllegalArgumentException("[contextLocator] argument cannot be null");
}
this.contextLocator = contextLocator;
this.wrapInProxies = wrapInProxies;
}
/**
* @see org.apache.wicket.injection.IFieldValueFactory#getFieldValue(java.lang.reflect.Field,
* java.lang.Object)
*/
public Object getFieldValue(Field field, Object fieldOwner)
{
if (field.isAnnotationPresent(SpringBean.class))
{
SpringBeanLocator locator = new SpringBeanLocator(getBeanName(field), field.getType(),
contextLocator);
// only check the cache if the bean is a singleton
if (cache.containsKey(locator))
{
return cache.get(locator);
}
final Object target;
if (wrapInProxies)
{
target = LazyInitProxyFactory.createProxy(field.getType(), locator);
}
else
{
target = locator.locateProxyTarget();
}
// only put the proxy into the cache if the bean is a singleton
if (locator.isSingletonBean())
{
cache.put(locator, target);
}
return target;
}
return null;
}
/**
*
* @param field
* @return bean name
*/
private String getBeanName(Field field)
{
SpringBean annot = field.getAnnotation(SpringBean.class);
String name = annot.name();
if (Strings.isEmpty(name))
{
name = beanNameCache.get(field.getType());
if (name == null)
{
name = getBeanNameOfClass(contextLocator.getSpringContext(), field.getType());
beanNameCache.put(field.getType(), name);
}
}
return name;
}
/**
* Returns the name of the Bean as registered to Spring. Throws IllegalState exception if none
* or more than one beans are found.
*
* @param ctx
* spring application context
* @param clazz
* bean class
* @throws IllegalStateException
* @return spring name of the bean
*/
private final String getBeanNameOfClass(ApplicationContext ctx, Class< ? > clazz)
{
// get the list of all possible matching beans
List<String> names = new ArrayList<String>(Arrays.asList(BeanFactoryUtils
.beanNamesForTypeIncludingAncestors(ctx, clazz)));
// filter out beans that are not condidates for autowiring
Iterator<String> it = names.iterator();
while (it.hasNext())
{
final String possibility = it.next();
if (BeanFactoryUtils.isFactoryDereference(possibility) ||
possibility.startsWith("scopedTarget."))
{
it.remove();
}
}
if (names.isEmpty())
{
throw new IllegalStateException("bean of type [" + clazz.getName() + "] not found");
}
else if (names.size() > 1)
{
if (ctx instanceof AbstractApplicationContext)
{
List<String> primaries = new ArrayList<String>();
for (String name : names)
{
BeanDefinition beanDef = getBeanDefinition(((AbstractApplicationContext)ctx)
.getBeanFactory(), name);
if (beanDef instanceof AbstractBeanDefinition)
{
if (((AbstractBeanDefinition)beanDef).isPrimary())
{
primaries.add(name);
}
}
}
if (primaries.size() == 1)
{
return primaries.get(0);
}
}
StringBuilder msg = new StringBuilder();
msg.append("More than one bean of type [");
msg.append(clazz.getName());
msg.append("] found, you have to specify the name of the bean ");
msg.append("(@SpringBean(name=\"foo\")) in order to resolve this conflict. ");
msg.append("Matched beans: ");
msg.append(Strings.join(",", names.toArray(new String[0])));
throw new IllegalStateException(msg.toString());
}
else
{
return names.get(0);
}
}
private BeanDefinition getBeanDefinition(ConfigurableListableBeanFactory beanFactory,
String name)
{
if (beanFactory.containsBeanDefinition(name))
{
return beanFactory.getBeanDefinition(name);
}
else
{
BeanFactory parent = beanFactory.getParentBeanFactory();
if (parent != null && parent instanceof ConfigurableListableBeanFactory)
{
return getBeanDefinition((ConfigurableListableBeanFactory)parent, name);
}
else
{
return null;
}
}
}
/**
* @see org.apache.wicket.injection.IFieldValueFactory#supportsField(java.lang.reflect.Field)
*/
public boolean supportsField(Field field)
{
return field.isAnnotationPresent(SpringBean.class);
}
}