org.impalaframework.web.integration.BaseLockingProxyServlet Maven / Gradle / Ivy
/*
* Copyright 2007-2010 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.impalaframework.web.integration;
import java.io.IOException;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.impalaframework.facade.ModuleManagementFacade;
import org.impalaframework.module.spi.FrameworkLockHolder;
import org.impalaframework.web.spring.helper.ImpalaServletUtils;
import org.impalaframework.web.utils.WebPathUtils;
/**
* Base {@link HttpServlet} which provides locking support for subclasses
* through a final implementation of
* {@link #service(HttpServletRequest, HttpServletResponse)} which wraps call to
* {@link #doService(HttpServletRequest, HttpServletResponse, ServletContext)}
* with a read lock obtained from {@link FrameworkLockHolder}
*
* @author Phil Zoio
*/
public abstract class BaseLockingProxyServlet extends HttpServlet {
private static final Log logger = LogFactory.getLog(BaseLockingProxyServlet.class);
private static final long serialVersionUID = 1L;
private FrameworkLockHolder frameworkLockHolder;
public BaseLockingProxyServlet() {
super();
}
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
ModuleManagementFacade moduleManagementFacade = ImpalaServletUtils.getModuleManagementFacade(config.getServletContext());
this.frameworkLockHolder = moduleManagementFacade.getFrameworkLockHolder();
}
@Override
public final void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
this.frameworkLockHolder.readLock();
WebPathUtils.maybeLogRequest(request, logger);
ServletContext context = getServletContext();
doService(request, response, context);
} finally {
this.frameworkLockHolder.readUnlock();
}
}
protected abstract void doService(HttpServletRequest request, HttpServletResponse response,
ServletContext context)
throws ServletException, IOException;
}