/*
* Copyright 2012-2017 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.boot.web.servlet;
import java.util.AbstractCollection;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.EventListener;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.servlet.Filter;
import javax.servlet.MultipartConfigElement;
import javax.servlet.Servlet;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.aop.scope.ScopedProxyUtils;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.core.annotation.AnnotationAwareOrderComparator;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
/**
* A collection {@link ServletContextInitializer}s obtained from a
* {@link ListableBeanFactory}. Includes all {@link ServletContextInitializer} beans and
* also adapts {@link Servlet}, {@link Filter} and certain {@link EventListener} beans.
* <p>
* Items are sorted so that adapted beans are top ({@link Servlet}, {@link Filter} then
* {@link EventListener}) and direct {@link ServletContextInitializer} beans are at the
* end. Further sorting is applied within these groups using the
* {@link AnnotationAwareOrderComparator}.
*
* @author Dave Syer
* @author Phillip Webb
* @since 1.4.0
*/
public class ServletContextInitializerBeans
extends AbstractCollection<ServletContextInitializer> {
private static final String DISPATCHER_SERVLET_NAME = "dispatcherServlet";
private static final Log logger = LogFactory
.getLog(ServletContextInitializerBeans.class);
/**
* Seen bean instances or bean names.
*/
private final Set<Object> seen = new HashSet<>();
private final MultiValueMap<Class<?>, ServletContextInitializer> initializers;
private List<ServletContextInitializer> sortedList;
public ServletContextInitializerBeans(ListableBeanFactory beanFactory) {
this.initializers = new LinkedMultiValueMap<>();
addServletContextInitializerBeans(beanFactory);
addAdaptableBeans(beanFactory);
List<ServletContextInitializer> sortedInitializers = new ArrayList<>();
for (Map.Entry<?, List<ServletContextInitializer>> entry : this.initializers
.entrySet()) {
AnnotationAwareOrderComparator.sort(entry.getValue());
sortedInitializers.addAll(entry.getValue());
}
this.sortedList = Collections.unmodifiableList(sortedInitializers);
}
private void addServletContextInitializerBeans(ListableBeanFactory beanFactory) {
for (Entry<String, ServletContextInitializer> initializerBean : getOrderedBeansOfType(
beanFactory, ServletContextInitializer.class)) {
addServletContextInitializerBean(initializerBean.getKey(),
initializerBean.getValue(), beanFactory);
}
}
private void addServletContextInitializerBean(String beanName,
ServletContextInitializer initializer, ListableBeanFactory beanFactory) {
if (initializer instanceof ServletRegistrationBean) {
Servlet source = ((ServletRegistrationBean<?>) initializer).getServlet();
addServletContextInitializerBean(Servlet.class, beanName, initializer,
beanFactory, source);
}
else if (initializer instanceof FilterRegistrationBean) {
Filter source = ((FilterRegistrationBean<?>) initializer).getFilter();
addServletContextInitializerBean(Filter.class, beanName, initializer,
beanFactory, source);
}
else if (initializer instanceof DelegatingFilterProxyRegistrationBean) {
String source = ((DelegatingFilterProxyRegistrationBean) initializer)
.getTargetBeanName();
addServletContextInitializerBean(Filter.class, beanName, initializer,
beanFactory, source);
}
else if (initializer instanceof ServletListenerRegistrationBean) {
EventListener source = ((ServletListenerRegistrationBean<?>) initializer)
.getListener();
addServletContextInitializerBean(EventListener.class, beanName, initializer,
beanFactory, source);
}
else {
addServletContextInitializerBean(ServletContextInitializer.class, beanName,
initializer, beanFactory, initializer);
}
}
private void addServletContextInitializerBean(Class<?> type, String beanName,
ServletContextInitializer initializer, ListableBeanFactory beanFactory,
Object source) {
this.initializers.add(type, initializer);
if (source != null) {
// Mark the underlying source as seen in case it wraps an existing bean
this.seen.add(source);
}
if (ServletContextInitializerBeans.logger.isDebugEnabled()) {
String resourceDescription = getResourceDescription(beanName, beanFactory);
int order = getOrder(initializer);
ServletContextInitializerBeans.logger.debug("Added existing "
+ type.getSimpleName() + " initializer bean '" + beanName
+ "'; order=" + order + ", resource=" + resourceDescription);
}
}
private String getResourceDescription(String beanName,
ListableBeanFactory beanFactory) {
if (beanFactory instanceof BeanDefinitionRegistry) {
BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
return registry.getBeanDefinition(beanName).getResourceDescription();
}
return "unknown";
}
@SuppressWarnings("unchecked")
private void addAdaptableBeans(ListableBeanFactory beanFactory) {
MultipartConfigElement multipartConfig = getMultipartConfig(beanFactory);
addAsRegistrationBean(beanFactory, Servlet.class,
new ServletRegistrationBeanAdapter(multipartConfig));
addAsRegistrationBean(beanFactory, Filter.class,
new FilterRegistrationBeanAdapter());
for (Class<?> listenerType : ServletListenerRegistrationBean
.getSupportedTypes()) {
addAsRegistrationBean(beanFactory, EventListener.class,
(Class<EventListener>) listenerType,
new ServletListenerRegistrationBeanAdapter());
}
}
private MultipartConfigElement getMultipartConfig(ListableBeanFactory beanFactory) {
List<Entry<String, MultipartConfigElement>> beans = getOrderedBeansOfType(
beanFactory, MultipartConfigElement.class);
return (beans.isEmpty() ? null : beans.get(0).getValue());
}
private <T> void addAsRegistrationBean(ListableBeanFactory beanFactory, Class<T> type,
RegistrationBeanAdapter<T> adapter) {
addAsRegistrationBean(beanFactory, type, type, adapter);
}
private <T, B extends T> void addAsRegistrationBean(ListableBeanFactory beanFactory,
Class<T> type, Class<B> beanType, RegistrationBeanAdapter<T> adapter) {
List<Map.Entry<String, B>> beans = getOrderedBeansOfType(beanFactory, beanType,
this.seen);
for (Entry<String, B> bean : beans) {
if (this.seen.add(bean.getValue())) {
int order = getOrder(bean.getValue());
String beanName = bean.getKey();
// One that we haven't already seen
RegistrationBean registration = adapter.createRegistrationBean(beanName,
bean.getValue(), beans.size());
registration.setName(beanName);
registration.setOrder(order);
this.initializers.add(type, registration);
if (ServletContextInitializerBeans.logger.isDebugEnabled()) {
ServletContextInitializerBeans.logger.debug(
"Created " + type.getSimpleName() + " initializer for bean '"
+ beanName + "'; order=" + order + ", resource="
+ getResourceDescription(beanName, beanFactory));
}
}
}
}
private int getOrder(Object value) {
return new AnnotationAwareOrderComparator() {
@Override
public int getOrder(Object obj) {
return super.getOrder(obj);
}
}.getOrder(value);
}
private <T> List<Entry<String, T>> getOrderedBeansOfType(
ListableBeanFactory beanFactory, Class<T> type) {
return getOrderedBeansOfType(beanFactory, type, Collections.emptySet());
}
private <T> List<Entry<String, T>> getOrderedBeansOfType(
ListableBeanFactory beanFactory, Class<T> type, Set<?> excludes) {
List<Entry<String, T>> beans = new ArrayList<>();
Comparator<Entry<String, T>> comparator = new Comparator<Entry<String, T>>() {
@Override
public int compare(Entry<String, T> o1, Entry<String, T> o2) {
return AnnotationAwareOrderComparator.INSTANCE.compare(o1.getValue(),
o2.getValue());
}
};
String[] names = beanFactory.getBeanNamesForType(type, true, false);
Map<String, T> map = new LinkedHashMap<>();
for (String name : names) {
if (!excludes.contains(name) && !ScopedProxyUtils.isScopedTarget(name)) {
T bean = beanFactory.getBean(name, type);
if (!excludes.contains(bean)) {
map.put(name, bean);
}
}
}
beans.addAll(map.entrySet());
Collections.sort(beans, comparator);
return beans;
}
@Override
public Iterator<ServletContextInitializer> iterator() {
return this.sortedList.iterator();
}
@Override
public int size() {
return this.sortedList.size();
}
/**
* Adapter to convert a given Bean type into a {@link RegistrationBean} (and hence a
* {@link ServletContextInitializer}.
*/
private interface RegistrationBeanAdapter<T> {
RegistrationBean createRegistrationBean(String name, T source,
int totalNumberOfSourceBeans);
}
/**
* {@link RegistrationBeanAdapter} for {@link Servlet} beans.
*/
private static class ServletRegistrationBeanAdapter
implements RegistrationBeanAdapter<Servlet> {
private final MultipartConfigElement multipartConfig;
ServletRegistrationBeanAdapter(MultipartConfigElement multipartConfig) {
this.multipartConfig = multipartConfig;
}
@Override
public RegistrationBean createRegistrationBean(String name, Servlet source,
int totalNumberOfSourceBeans) {
String url = (totalNumberOfSourceBeans == 1 ? "/" : "/" + name + "/");
if (name.equals(DISPATCHER_SERVLET_NAME)) {
url = "/"; // always map the main dispatcherServlet to "/"
}
ServletRegistrationBean<Servlet> bean = new ServletRegistrationBean<>(source,
url);
bean.setMultipartConfig(this.multipartConfig);
return bean;
}
}
/**
* {@link RegistrationBeanAdapter} for {@link Filter} beans.
*/
private static class FilterRegistrationBeanAdapter
implements RegistrationBeanAdapter<Filter> {
@Override
public RegistrationBean createRegistrationBean(String name, Filter source,
int totalNumberOfSourceBeans) {
return new FilterRegistrationBean<>(source);
}
}
/**
* {@link RegistrationBeanAdapter} for certain {@link EventListener} beans.
*/
private static class ServletListenerRegistrationBeanAdapter
implements RegistrationBeanAdapter<EventListener> {
@Override
public RegistrationBean createRegistrationBean(String name, EventListener source,
int totalNumberOfSourceBeans) {
return new ServletListenerRegistrationBean<>(source);
}
}
}