/*
* Copyright 2012-2013 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.autoconfigure.websocket;
import javax.servlet.Servlet;
import org.apache.catalina.Context;
import org.apache.catalina.startup.Tomcat;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanUtils;
import org.springframework.boot.autoconfigure.AutoConfigureBefore;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.web.EmbeddedServletContainerAutoConfiguration;
import org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainer;
import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer;
import org.springframework.boot.context.embedded.tomcat.TomcatContextCustomizer;
import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
import org.springframework.boot.context.web.NonEmbeddedServletContainerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.web.socket.WebSocketHandler;
/**
* Auto configuration for websocket server in embedded Tomcat. If
* <code>spring-websocket</code> is detected on the classpath then we add a listener that
* installs the Tomcat Websocket initializer. In a non-embedded container it should
* already be there.
*
* @author Dave Syer
* @author Phillip Webb
*/
@Configuration
@ConditionalOnClass(name = "org.apache.tomcat.websocket.server.WsSci", value = {
Servlet.class, Tomcat.class, WebSocketHandler.class })
@AutoConfigureBefore(EmbeddedServletContainerAutoConfiguration.class)
public class WebSocketAutoConfiguration {
private static final String TOMCAT_7_LISTENER_TYPE = "org.apache.catalina.deploy.ApplicationListener";
private static final String TOMCAT_8_LISTENER_TYPE = "org.apache.tomcat.util.descriptor.web.ApplicationListener";
private static final String WS_LISTENER = "org.apache.tomcat.websocket.server.WsContextListener";
private static Log logger = LogFactory.getLog(WebSocketAutoConfiguration.class);
@Bean
@ConditionalOnMissingBean(name = "websocketContainerCustomizer")
public EmbeddedServletContainerCustomizer websocketContainerCustomizer() {
return new EmbeddedServletContainerCustomizer() {
@Override
public void customize(ConfigurableEmbeddedServletContainer container) {
if (container instanceof NonEmbeddedServletContainerFactory) {
logger.info("NonEmbeddedServletContainerFactory detected. Websockets "
+ "support should be native so this normally is not a problem.");
return;
}
Assert.state(container instanceof TomcatEmbeddedServletContainerFactory,
"Websockets are currently only supported in Tomcat (found "
+ container.getClass() + "). ");
TomcatEmbeddedServletContainerFactory tomcatContainer = (TomcatEmbeddedServletContainerFactory) container;
tomcatContainer.addContextCustomizers(new TomcatContextCustomizer() {
@Override
public void customize(Context context) {
addListener(context, findListenerType());
}
});
}
};
}
private static Class<?> findListenerType() {
if (ClassUtils.isPresent(TOMCAT_7_LISTENER_TYPE, null)) {
return ClassUtils.resolveClassName(TOMCAT_7_LISTENER_TYPE, null);
}
if (ClassUtils.isPresent(TOMCAT_8_LISTENER_TYPE, null)) {
return ClassUtils.resolveClassName(TOMCAT_8_LISTENER_TYPE, null);
}
// With Tomcat 8.0.8 ApplicationListener is not required
return null;
}
/**
* Instead of registering the WsSci directly as a ServletContainerInitializer, we use
* the ApplicationListener provided by Tomcat. Unfortunately the ApplicationListener
* class moved packages in Tomcat 8 and been deleted in 8.0.8 so we have to use
* reflection.
* @param context the current context
* @param listenerType the type of listener to add
*/
private static void addListener(Context context, Class<?> listenerType) {
if (listenerType == null) {
ReflectionUtils.invokeMethod(ClassUtils.getMethod(context.getClass(),
"addApplicationListener", String.class), context, WS_LISTENER);
}
else {
Object instance = BeanUtils.instantiateClass(
ClassUtils.getConstructorIfAvailable(listenerType, String.class,
boolean.class), WS_LISTENER, false);
ReflectionUtils.invokeMethod(ClassUtils.getMethod(context.getClass(),
"addApplicationListener", listenerType), context, instance);
}
}
}