/*

  * This software is licensed under the Apache License, Version 2.0

  * (the "License") agreement; 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 net.admin4j.ui.filters;

 import java.io.IOException;

 import java.io.StringWriter;

 import java.util.HashMap;

 import java.util.Map;

 import javax.servlet.Filter;

 import javax.servlet.FilterChain;

 import javax.servlet.FilterConfig;

 import javax.servlet.ServletException;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 import javax.servlet.http.HttpServletRequest;

 import net.admin4j.config.Admin4JConfiguration;

 import net.admin4j.deps.commons.lang3.StringUtils;

 import net.admin4j.timer.TaskTimer;

 import net.admin4j.timer.TaskTimerFactory;

 import net.admin4j.ui.filters.consolidator.DefaultHttpRequestConsolidator;

 import net.admin4j.ui.filters.consolidator.HttpRequestConsolidator;

 import net.admin4j.util.Admin4jRuntimeException;

 import net.admin4j.util.FreemarkerUtils;

 import net.admin4j.util.GuiUtils;

 import net.admin4j.util.HostUtils;

 import net.admin4j.util.ServletUtils;

 import freemarker.template.Configuration;

 import freemarker.template.Template;

 /**

  *

  * This filter allows you to enable performance monitoring. Notification will be

  * sent when a defined threshold limit is reached.

  *

  * <p>

  * Initialization parameters for this filter are as follows:

  * </p>

  * <li>notification.threshold.in.millis - Optional. If set, a notification will

  * be issued should a page take longer than the specified number of

  * milliseconds. For this option to work, values must be provided for notifier</li>

  * <li>notifier -- Optional. Handles admin notification. See documentation for

  * the Notifier you're using for any additional configuration requirements. For

  * example, 'net.admin4j.util.notify.EmailNotifier'.</li>

  *

  * @author D. Ashmore

  * @since 1.0

  */

 public class PerformanceMonitoringFilter extends BaseNotificationFilter

 implements Filter {

         private long notificationThresholdInMillis = Long.MAX_VALUE;

         private HttpRequestConsolidator consolidator = new DefaultHttpRequestConsolidator();

         public void destroy() {

         }

         public void doFilter(ServletRequest request, ServletResponse response,

                         FilterChain filterChain) throws IOException, ServletException {

                 TaskTimer perfMonitor = null;

                 HttpServletRequest httpRequest = null;

                 String serviceName = null;

                 long beginTime = System.currentTimeMillis();

                 try {

                         /*

                          * Under no circumstances should an Admin4J error 'mask' the

                          * underlying error for an application. Hence, all Admin4J work is

                          * surrounded by a try/catch making sure to throw the underlying

                          * exception up the chain.

                          */

                         try {

                                 httpRequest = (HttpServletRequest) request;

                                 serviceName = httpRequest.getRequestURI();

                                 perfMonitor = TaskTimerFactory.start(serviceName);

                         } catch (Throwable fubar) {

                                 logger.error("Error starting performance monitor.", fubar);

                         }

                         filterChain.doFilter(request, response);

                         try {

                                 long durationInMillis = System.currentTimeMillis() - beginTime;

                                 double durationInSeconds = durationInMillis / 1000;

                                 if (durationInMillis > notificationThresholdInMillis) {

                                         Configuration cfg = new Configuration();

                                         cfg.setClassForTemplateLoading(

                                                         ErrorNotificationFilter.class, "");

                                         Map<String, Object> variableMap = new HashMap<String, Object>();

                                         variableMap.put("request", httpRequest);

                                         variableMap.put("GuiUtils", new GuiUtils());

                                         variableMap.put("host", HostUtils.getHostName());

                                         variableMap.put("timeInSeconds", durationInSeconds);

                                         variableMap.put(

                                                         "sessionAttributeList",

                                                         ServletUtils.listSessionAttributes(httpRequest.getSession()));

                                         variableMap.put("requestAttributeList",

                                                         ServletUtils.listRequestAttributes(httpRequest));

                                         Template temp = null;

                                         if (this.notifier.supportsHtml()) {

                                                 temp = FreemarkerUtils.createConfiguredTemplate(

                                                                 this.getClass(),

                                                                 "slowPerformanceNotificationMessageHtml.ftl");

                                         }

                                         else {

                                                 temp = FreemarkerUtils.createConfiguredTemplate(

                                                                 this.getClass(),

                                                                 "slowPerformanceNotificationMessageText.ftl");

                                         }

                                         StringWriter message = new StringWriter();

                                         try {

                                                 temp.process(variableMap, message);

                                         } catch (Exception e) {

                                                 throw new Admin4jRuntimeException(e);

                                         }

                                         String subject = ServletUtils.getApplicationName(httpRequest)

                                                         + "@"

                                                         + HostUtils.getHostName()

                                                         + ": "

                                                         + httpRequest.getRequestURI()

                                                         + ": "

                                                         + "Response time over "

                                                         + notificationThresholdInMillis + " ms";

                                         this.notifier.notify(subject, message.toString());

                                 }

                         } catch (Throwable fubar) {

                                 logger.error("Error providing performance notification.", fubar);

                         }

                 } catch (ServletException se) {

                         throw se;

                 } catch (Throwable ex) {

                         throw new ServletException(ex);

                 } finally {

                         if (perfMonitor != null) {

                                 perfMonitor.stop();

                         }

                 }

         }

         /*

          * (non-Javadoc)

          *

          * @see

          * net.admin4j.ui.filters.BaseNotificationFilter#init(javax.servlet.FilterConfig

          * )

          */

         @Override

         public void init(FilterConfig config) throws ServletException {

                 super.init(config);

                 String notifyThresholdInMillisStr = config.getInitParameter("notification.threshold.in.millis");

                 if (!StringUtils.isEmpty(notifyThresholdInMillisStr)) {

                         try {

                                 this.notificationThresholdInMillis = Long.parseLong(notifyThresholdInMillisStr);

                         } catch (NumberFormatException e) {

                                 this.notificationThresholdInMillis = Long.MAX_VALUE;

                                 throw new Admin4jRuntimeException(

                                                 "notification.threshold.in.millis secification not numeric",

                                                 e).addContextValue("notification.threshold.in.millis",

                                                                 notifyThresholdInMillisStr);

                         }

                 }

                 else if (Admin4JConfiguration.getWebTransactionPerformanceNotificationThresholdInMillis() != null) {

                         this.notificationThresholdInMillis = Admin4JConfiguration.getWebTransactionPerformanceNotificationThresholdInMillis();

                 }

                 String requestConsolidatorClassStr = config.getInitParameter("uri.consolidator");

                 if (!StringUtils.isEmpty(requestConsolidatorClassStr)) {

                         try {

                                 consolidator = (HttpRequestConsolidator) Class.forName(

                                                 requestConsolidatorClassStr)

                                                 .newInstance();

                         } catch (Exception e) {

                                 throw new Admin4jRuntimeException(

                                                 "uri.consolidator cannot be instantiated", e).addContextValue(

                                                                 "uri.consolidator", requestConsolidatorClassStr);

                         }

                 }

                 else if (Admin4JConfiguration.getPerformanceRestUriConsolidator() != null) {

                         consolidator = Admin4JConfiguration.getPerformanceRestUriConsolidator();

                 }

         }

 }