SpringHttpConsoleServlet.java

/*
 *
 * Copyright (c) void.fm
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this list
 * of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice, this
 * list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 *
 * Neither the name void.fm nor the names of its contributors may be
 * used to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

package etm.contrib.integration.spring.web;

import etm.contrib.integration.web.HttpConsoleServlet;
import etm.core.monitor.EtmMonitor;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import javax.servlet.ServletException;

/**
 * A servlet that provides access to aggregated performance statistics for etm.contrib.integration.spring managed EtmMonitor instances similar to
 * a standalone {@link etm.contrib.console.HttpConsoleServer}. The servlet requires the existence of an Spring
 * WebApplicationContext that was created through a Spring <code>ContextLoaderListener</code> or
 * <code>ContextLoaderServlet</code> (<i>It should be possible to locate the WebApplicationContext with
 * WebApplicationContextUtils.getRequiredWebApplicationContext()</i>).
 * <p/>
 * Usually the servlet is able to locate the EtmMonitor automatically, however if you have more than one EtmMonitor
 * instance you need specify the monitor bean name as specified in your etm.contrib.integration.spring configuration. Therefore add the servlet
 * init parameter called <code>etmMonitorName</code> holding its name.
 * <p/>
 * Example:
 * <pre>
 * <servlet>
 *  <servlet-name>performanceMonitor</servlet-name>
 *  <servlet-class>etm.contrib.integration.etm.contrib.integration.spring.web.SpringHttpConsoleServlet</servlet-class>
 *  <init-param>
 *    <param-name>etmMonitorName</param-name>
 *    <param-value>myEtmMonitor</param-value>
 *  </init-param>
 * </servlet>
 * </pre>
 *
 * @author void.fm
 * @version $Revision$
 * @since 1.2.0
 */
public class SpringHttpConsoleServlet extends HttpConsoleServlet {

  
  protected EtmMonitor getEtmMonitor() throws ServletException {
    // retrieve name of EtmMonitor to use. may be null
    String etmMonitorName = servletConfig.getInitParameter(SpringEtmMonitorContextSupport.ETM_MONITOR_PARAMETER_NAME);
    WebApplicationContext ctx = WebApplicationContextUtils.getRequiredWebApplicationContext(servletConfig.getServletContext());
    return SpringEtmMonitorContextSupport.locateEtmMonitor(ctx, etmMonitorName);
  }
}