Tomcat example source code file (StatusManagerServlet.java)

This example Tomcat source code file (StatusManagerServlet.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Tomcat tags/keywords

globalrequestprocessor, http, management, mbeanservernotification, object, objectinstance, objectinstance, objectname, objectname, request, requestprocessor, response, servlet, servletexception, string, string, threadpool, util, vector, vector

The Tomcat StatusManagerServlet.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.catalina.manager;


import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Set;
import java.util.Vector;

import javax.management.MBeanServer;
import javax.management.MBeanServerNotification;
import javax.management.Notification;
import javax.management.NotificationListener;
import javax.management.ObjectInstance;
import javax.management.ObjectName;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.catalina.util.ServerInfo;
import org.apache.catalina.util.StringManager;
import org.apache.tomcat.util.modeler.Registry;

/**
 * This servlet will display a complete status of the HTTP/1.1 connector.
 *
 * @author Remy Maucherat
 * @version $Revision: 467222 $ $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
 */

public class StatusManagerServlet
    extends HttpServlet implements NotificationListener {


    // ----------------------------------------------------- Instance Variables


    /**
     * The debugging detail level for this servlet.
     */
    private int debug = 0;


    /**
     * MBean server.
     */
    protected MBeanServer mBeanServer = null;


    /**
     * Vector of protocol handlers object names.
     */
    protected Vector protocolHandlers = new Vector();


    /**
     * Vector of thread pools object names.
     */
    protected Vector threadPools = new Vector();


    /**
     * Vector of request processors object names.
     */
    protected Vector requestProcessors = new Vector();


    /**
     * Vector of global request processors object names.
     */
    protected Vector globalRequestProcessors = new Vector();


    /**
     * The string manager for this package.
     */
    protected static StringManager sm =
        StringManager.getManager(Constants.Package);


    // --------------------------------------------------------- Public Methods


    /**
     * Initialize this servlet.
     */
    public void init() throws ServletException {

        // Retrieve the MBean server
        mBeanServer = Registry.getRegistry(null, null).getMBeanServer();

        // Set our properties from the initialization parameters
        String value = null;
        try {
            value = getServletConfig().getInitParameter("debug");
            debug = Integer.parseInt(value);
        } catch (Throwable t) {
            ;
        }

        try {

            // Query protocol handlers
            String onStr = "*:type=ProtocolHandler,*";
            ObjectName objectName = new ObjectName(onStr);
            Set set = mBeanServer.queryMBeans(objectName, null);
            Iterator iterator = set.iterator();
            while (iterator.hasNext()) {
                ObjectInstance oi = (ObjectInstance) iterator.next();
                protocolHandlers.addElement(oi.getObjectName());
            }

            // Query Thread Pools
            onStr = "*:type=ThreadPool,*";
            objectName = new ObjectName(onStr);
            set = mBeanServer.queryMBeans(objectName, null);
            iterator = set.iterator();
            while (iterator.hasNext()) {
                ObjectInstance oi = (ObjectInstance) iterator.next();
                threadPools.addElement(oi.getObjectName());
            }

            // Query Global Request Processors
            onStr = "*:type=GlobalRequestProcessor,*";
            objectName = new ObjectName(onStr);
            set = mBeanServer.queryMBeans(objectName, null);
            iterator = set.iterator();
            while (iterator.hasNext()) {
                ObjectInstance oi = (ObjectInstance) iterator.next();
                globalRequestProcessors.addElement(oi.getObjectName());
            }

            // Query Request Processors
            onStr = "*:type=RequestProcessor,*";
            objectName = new ObjectName(onStr);
            set = mBeanServer.queryMBeans(objectName, null);
            iterator = set.iterator();
            while (iterator.hasNext()) {
                ObjectInstance oi = (ObjectInstance) iterator.next();
                requestProcessors.addElement(oi.getObjectName());
            }

            // Register with MBean server
            onStr = "JMImplementation:type=MBeanServerDelegate";
            objectName = new ObjectName(onStr);
            mBeanServer.addNotificationListener(objectName, this, null, null);

        } catch (Exception e) {
            e.printStackTrace();
        }

    }


    /**
     * Finalize this servlet.
     */
    public void destroy() {

        ;       // No actions necessary

    }


    /**
     * Process a GET request for the specified resource.
     *
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet-specified error occurs
     */
    public void doGet(HttpServletRequest request,
                      HttpServletResponse response)
        throws IOException, ServletException {

        // mode is flag for HTML or XML output
        int mode = 0;
        // if ?XML=true, set the mode to XML
        if (request.getParameter("XML") != null 
            && request.getParameter("XML").equals("true")) {
            mode = 1;
        }
        StatusTransformer.setContentType(response, mode);

        PrintWriter writer = response.getWriter();

        boolean completeStatus = false;
        if ((request.getPathInfo() != null) 
            && (request.getPathInfo().equals("/all"))) {
            completeStatus = true;
        }
        // use StatusTransformer to output status
        StatusTransformer.writeHeader(writer,mode);

        // Body Header Section
        Object[] args = new Object[2];
        args[0] = request.getContextPath();
        if (completeStatus) {
            args[1] = sm.getString("statusServlet.complete");
        } else {
            args[1] = sm.getString("statusServlet.title");
        }
        // use StatusTransformer to output status
        StatusTransformer.writeBody(writer,args,mode);

        // Manager Section
        args = new Object[9];
        args[0] = sm.getString("htmlManagerServlet.manager");
        args[1] = response.encodeURL(request.getContextPath() + "/html/list");
        args[2] = sm.getString("htmlManagerServlet.list");
        args[3] = response.encodeURL
            (request.getContextPath() + "/" +
             sm.getString("htmlManagerServlet.helpHtmlManagerFile"));
        args[4] = sm.getString("htmlManagerServlet.helpHtmlManager");
        args[5] = response.encodeURL
            (request.getContextPath() + "/" +
             sm.getString("htmlManagerServlet.helpManagerFile"));
        args[6] = sm.getString("htmlManagerServlet.helpManager");
        if (completeStatus) {
            args[7] = response.encodeURL
                (request.getContextPath() + "/status");
            args[8] = sm.getString("statusServlet.title");
        } else {
            args[7] = response.encodeURL
                (request.getContextPath() + "/status/all");
            args[8] = sm.getString("statusServlet.complete");
        }
        // use StatusTransformer to output status
        StatusTransformer.writeManager(writer,args,mode);

        // Server Header Section
        args = new Object[7];
        args[0] = sm.getString("htmlManagerServlet.serverTitle");
        args[1] = sm.getString("htmlManagerServlet.serverVersion");
        args[2] = sm.getString("htmlManagerServlet.serverJVMVersion");
        args[3] = sm.getString("htmlManagerServlet.serverJVMVendor");
        args[4] = sm.getString("htmlManagerServlet.serverOSName");
        args[5] = sm.getString("htmlManagerServlet.serverOSVersion");
        args[6] = sm.getString("htmlManagerServlet.serverOSArch");
        // use StatusTransformer to output status
        StatusTransformer.writePageHeading(writer,args,mode);

        // Server Row Section
        args = new Object[6];
        args[0] = ServerInfo.getServerInfo();
        args[1] = System.getProperty("java.runtime.version");
        args[2] = System.getProperty("java.vm.vendor");
        args[3] = System.getProperty("os.name");
        args[4] = System.getProperty("os.version");
        args[5] = System.getProperty("os.arch");
        // use StatusTransformer to output status
        StatusTransformer.writeServerInfo(writer, args, mode);

        try {

            // Display operating system statistics using APR if available
            StatusTransformer.writeOSState(writer,mode);

            // Display virtual machine statistics
            StatusTransformer.writeVMState(writer,mode);

            Enumeration enumeration = threadPools.elements();
            while (enumeration.hasMoreElements()) {
                ObjectName objectName = (ObjectName) enumeration.nextElement();
                String name = objectName.getKeyProperty("name");
                // use StatusTransformer to output status
                StatusTransformer.writeConnectorState
                    (writer, objectName,
                     name, mBeanServer, globalRequestProcessors,
                     requestProcessors, mode);
            }

            if ((request.getPathInfo() != null) 
                && (request.getPathInfo().equals("/all"))) {
                // Note: Retrieving the full status is much slower
                // use StatusTransformer to output status
                StatusTransformer.writeDetailedState
                    (writer, mBeanServer, mode);
            }

        } catch (Exception e) {
            throw new ServletException(e);
        }

        // use StatusTransformer to output status
        StatusTransformer.writeFooter(writer, mode);

    }

    // ------------------------------------------- NotificationListener Methods


    public void handleNotification(Notification notification,
                                   java.lang.Object handback) {

        if (notification instanceof MBeanServerNotification) {
            ObjectName objectName = 
                ((MBeanServerNotification) notification).getMBeanName();
            if (notification.getType().equals
                (MBeanServerNotification.REGISTRATION_NOTIFICATION)) {
                String type = objectName.getKeyProperty("type");
                if (type != null) {
                    if (type.equals("ProtocolHandler")) {
                        protocolHandlers.addElement(objectName);
                    } else if (type.equals("ThreadPool")) {
                        threadPools.addElement(objectName);
                    } else if (type.equals("GlobalRequestProcessor")) {
                        globalRequestProcessors.addElement(objectName);
                    } else if (type.equals("RequestProcessor")) {
                        requestProcessors.addElement(objectName);
                    }
                }
            } else if (notification.getType().equals
                       (MBeanServerNotification.UNREGISTRATION_NOTIFICATION)) {
                String type = objectName.getKeyProperty("type");
                if (type != null) {
                    if (type.equals("ProtocolHandler")) {
                        protocolHandlers.removeElement(objectName);
                    } else if (type.equals("ThreadPool")) {
                        threadPools.removeElement(objectName);
                    } else if (type.equals("GlobalRequestProcessor")) {
                        globalRequestProcessors.removeElement(objectName);
                    } else if (type.equals("RequestProcessor")) {
                        requestProcessors.removeElement(objectName);
                    }
                }
                String j2eeType = objectName.getKeyProperty("j2eeType");
                if (j2eeType != null) {
                    
                }
            }
        }

    }


}