org.camunda.bpm.application.impl.ServletProcessApplicationDeployer Maven / Gradle / Ivy
/*
* Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH
* under one or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information regarding copyright
* ownership. Camunda licenses this file to you under the Apache License,
* Version 2.0; 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.camunda.bpm.application.impl;
import java.util.HashSet;
import java.util.Set;
import javax.servlet.ServletContainerInitializer;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextListener;
import javax.servlet.ServletException;
import javax.servlet.annotation.HandlesTypes;
import org.camunda.bpm.application.AbstractProcessApplication;
import org.camunda.bpm.application.ProcessApplication;
import org.camunda.bpm.engine.impl.ProcessEngineLogger;
/**
* This class is an implementation of {@link ServletContainerInitializer} and
* is notified whenever a subclass of {@link ServletProcessApplication} annotated
* with the {@link ProcessApplication} annotation is deployed. In such an event,
* we automatically add the class as {@link ServletContextListener} to the
* {@link ServletContext}.
*
* NOTE: Only works with Servlet 3.0 or better.
*
* @author Daniel Meyer
*
*/
@HandlesTypes(ProcessApplication.class)
public class ServletProcessApplicationDeployer implements ServletContainerInitializer {
private static ProcessApplicationLogger LOG = ProcessEngineLogger.PROCESS_APPLICATION_LOGGER;
public void onStartup(Set> c, ServletContext ctx) throws ServletException {
if(c == null || c.isEmpty()) {
// skip deployments that do not carry a PA
return;
}
if (c.contains(ProcessApplication.class)) {
// this is a workaround for a bug in WebSphere-8.5 who
// ships the annotation itself as part of the discovered classes.
// copy into a fresh Set as we don't know if the original Set is mutable or immutable.
c = new HashSet>(c);
// and now remove the annotation itself.
c.remove(ProcessApplication.class);
}
String contextPath = ctx.getContextPath();
if(c.size() > 1) {
// a deployment must only contain a single PA
throw LOG.multiplePasException(c, contextPath);
} else if(c.size() == 1) {
Class paClass = c.iterator().next();
// validate whether it is a legal Process Application
if(!AbstractProcessApplication.class.isAssignableFrom(paClass)) {
throw LOG.paWrongTypeException(paClass);
}
// add it as listener if it's a ServletProcessApplication
if(ServletProcessApplication.class.isAssignableFrom(paClass)) {
LOG.detectedPa(paClass);
ctx.addListener(paClass.getName());
}
}
else {
LOG.servletDeployerNoPaFound(contextPath);
}
}
}