Tomcat example source code file (CoordinationDemo.java)

This example Tomcat source code file (CoordinationDemo.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

coordinationdemo, exception, exception, io, member, multi_thread, status, string, string, stringbuffer, stringbuffer, stringtokenizer, system, thread, thread, util

The Tomcat CoordinationDemo.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.tribes.demos;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

import org.apache.catalina.tribes.ChannelInterceptor;
import org.apache.catalina.tribes.ChannelInterceptor.InterceptorEvent;
import org.apache.catalina.tribes.Member;
import org.apache.catalina.tribes.group.GroupChannel;
import org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor;
import org.apache.catalina.tribes.group.interceptors.NonBlockingCoordinator;
import org.apache.catalina.tribes.group.interceptors.TcpFailureDetector;
import org.apache.catalina.tribes.transport.ReceiverBase;
import org.apache.catalina.tribes.util.Arrays;



public class CoordinationDemo {
    static int CHANNEL_COUNT = 5;
    static int SCREEN_WIDTH = 120;
    static long SLEEP_TIME = 10;
    static int CLEAR_SCREEN = 30;
    static boolean MULTI_THREAD = false;
    static boolean[] VIEW_EVENTS = new boolean[255];
    StringBuffer statusLine = new StringBuffer();
    Status[] status = null;
    BufferedReader reader = null;
    /**
     * Construct and show the application.
     */
    public CoordinationDemo() {
    }
    
    public void init() {
        reader = new BufferedReader(new InputStreamReader(System.in));
        status = new Status[CHANNEL_COUNT];
    }
    
    
    public void clearScreen() {
        StringBuffer buf = new StringBuffer(700);
        for (int i=0; i<CLEAR_SCREEN; i++ ) buf.append("\n");
        System.out.println(buf);
    }

    public void printMenuOptions() {
        System.out.println("Commands:");
        System.out.println("\tstart [member id]");
        System.out.println("\tstop  [member id]");
        System.out.println("\tprint (refresh)");
        System.out.println("\tquit");
        System.out.print("Enter command:");
    }
    
    public synchronized void printScreen() {
        clearScreen();
        System.out.println(" ###."+getHeader());
        for ( int i=0; i<status.length; i++ ) {
            System.out.print(leftfill(String.valueOf(i+1)+".",5," "));
            if ( status[i] != null ) System.out.print(status[i].getStatusLine());
        }
        System.out.println("\n\n");
        System.out.println("Overall status:"+statusLine);
        printMenuOptions();
        
    }
    
    public String getHeader() {
        //member - 30
        //running- 10
        //coord - 30
        //view-id - 24
        //view count - 8

        StringBuffer buf = new StringBuffer();
        buf.append(leftfill("Member",30," "));
        buf.append(leftfill("Running",10," "));
        buf.append(leftfill("Coord",30," "));
        buf.append(leftfill("View-id(short)",24," "));
        buf.append(leftfill("Count",8," "));
        buf.append("\n");
        
        buf.append(rightfill("==="+new java.sql.Timestamp(System.currentTimeMillis()).toString(),SCREEN_WIDTH,"="));
        buf.append("\n");
        return buf.toString();
    }
    
    public String[] tokenize(String line) {
        StringTokenizer tz = new StringTokenizer(line," ");
        String[] result = new String[tz.countTokens()];
        for (int i=0; i<result.length; i++ ) result[i] = tz.nextToken();
        return result;
    }
    
    public void waitForInput() throws IOException {
        for ( int i=0; i<status.length; i++ ) status[i] = new Status(this);
        printScreen();
        String l = reader.readLine();
        String[] args = tokenize(l);
        while ( args.length >= 1 && (!"quit".equalsIgnoreCase(args[0]))) {
            if ("start".equalsIgnoreCase(args[0])) {
                cmdStart(args);
            } else if ("stop".equalsIgnoreCase(args[0])) {
                cmdStop(args);

            }
            printScreen();
            l = reader.readLine();
            args = tokenize(l);
        }
        for ( int i=0; i<status.length; i++ ) status[i].stop();
    }

    private void cmdStop(String[] args) {
        if ( args.length == 1 ) {
            setSystemStatus("System shutting down...");
            Thread[] t = new Thread[CHANNEL_COUNT];
            for (int i = 0; i < status.length; i++) {
                final int j = i;
                t[j] = new Thread() {
                    public void run() {
                        status[j].stop();
                    }
                };
            }
            for (int i = 0; i < status.length; i++) if (MULTI_THREAD ) t[i].start(); else t[i].run();
            setSystemStatus("System stopped.");
        } else { 
            int index = -1;
            try { index = Integer.parseInt(args[1])-1;}catch ( Exception x ) {setSystemStatus("Invalid index:"+args[1]);}
            if ( index >= 0 ) {
                setSystemStatus("Stopping member:"+(index+1));
                status[index].stop();
                setSystemStatus("Member stopped:"+(index+1));
            }
        }
    }

    private void cmdStart(String[] args) {
        if ( args.length == 1 ) {
            setSystemStatus("System starting up...");
            Thread[] t = new Thread[CHANNEL_COUNT];
            for (int i = 0; i < status.length; i++) {
                final int j = i;
                t[j] = new Thread() {
                    public void run() {
                        status[j].start();
                    }
                };
            }
            for (int i = 0; i < status.length; i++) if (MULTI_THREAD ) t[i].start(); else t[i].run();
            setSystemStatus("System started.");
        } else { 
            int index = -1;
            try { index = Integer.parseInt(args[1])-1;}catch ( Exception x ) {setSystemStatus("Invalid index:"+args[1]);}
            if ( index >= 0 ) {
                setSystemStatus("Starting member:"+(index+1));
                status[index].start();
                setSystemStatus("Member started:"+(index+1));
            }
        }
    }

    public void setSystemStatus(String status) {
        statusLine.delete(0,statusLine.length());
        statusLine.append(status);
    }
    
    
    
    public static void setEvents(String events) {
        java.util.Arrays.fill(VIEW_EVENTS,false);
        StringTokenizer t = new StringTokenizer(events,",");
        while (t.hasMoreTokens() ) {
            int idx = Integer.parseInt(t.nextToken());
            VIEW_EVENTS[idx] = true;
        }
    }
    
    public static void run(String[] args,CoordinationDemo demo) throws Exception {
        usage();
        java.util.Arrays.fill(VIEW_EVENTS,true);

        for (int i=0; i<args.length; i++ ) {
            if ( "-c".equals(args[i]) )
                CHANNEL_COUNT = Integer.parseInt(args[++i]);
            else if ( "-t".equals(args[i]) )
                MULTI_THREAD = Boolean.parseBoolean(args[++i]);
            else if ( "-s".equals(args[i]) )
                SLEEP_TIME = Long.parseLong(args[++i]);
            else if ( "-sc".equals(args[i]) )
                CLEAR_SCREEN = Integer.parseInt(args[++i]);
            else if ( "-p".equals(args[i]) )
                setEvents(args[++i]);
            else if ( "-h".equals(args[i]) ) System.exit(0);
        }
        demo.init();
        demo.waitForInput();
    }    

    private static void usage() {
        System.out.println("Usage:");
        System.out.println("\tjava org.apache.catalina.tribes.demos.CoordinationDemo -c channel-count(int) -t multi-thread(true|false) -s sleep-time(ms) -sc clear-screen(int) -p view_events_csv(1,2,5,7)");
        System.out.println("Example:");
        System.out.println("\tjava o.a.c.t.d.CoordinationDemo -> starts demo single threaded start/stop with 5 channels");
        System.out.println("\tjava o.a.c.t.d.CoordinationDemo -c 10 -> starts demo single threaded start/stop with 10 channels");
        System.out.println("\tjava o.a.c.t.d.CoordinationDemo -c 7 -t true -s 1000 -sc 50-> starts demo multi threaded start/stop with 7 channels and 1 second sleep time between events and 50 lines to clear screen");
        System.out.println("\tjava o.a.c.t.d.CoordinationDemo -t true -p 12 -> starts demo multi threaded start/stop with 5 channels and only prints the EVT_CONF_RX event");
        System.out.println();
    }
    public static void main(String[] args) throws Exception {
        CoordinationDemo demo = new CoordinationDemo();
        run(args,demo);
    }
    
    public static String leftfill(String value, int length, String ch) {
        return fill(value,length,ch,true);
    }
    
    public static String rightfill(String value, int length, String ch) {
        return fill(value,length,ch,false);
    }    

    public static String fill(String value, int length, String ch, boolean left) {
        StringBuffer buf = new StringBuffer();
        if ( !left ) buf.append(value.trim());
        for (int i=value.trim().length(); i<length; i++ ) buf.append(ch);
        if ( left ) buf.append(value.trim());
        return buf.toString();
    }
    
    
    public static class Status {
        public CoordinationDemo parent;
        public GroupChannel channel;
        NonBlockingCoordinator interceptor = null;
        public String status;
        public Exception error;
        public String startstatus = "new";
        
        public Status(CoordinationDemo parent) {
            this.parent = parent;
        }
        
        public String getStatusLine() {
            //member - 30
            //running- 10
            //coord - 30
            //view-id - 24
            //view count - 8
            StringBuffer buf = new StringBuffer();
            String local = "";
            String coord = "";
            String viewId = "";
            String count = "0";
            if ( channel != null ) {
                Member lm = channel.getLocalMember(false);
                local = lm!=null?lm.getName():"";
                coord = interceptor!=null && interceptor.getCoordinator()!=null?interceptor.getCoordinator().getName():"";
                viewId = getByteString(interceptor.getViewId()!=null?interceptor.getViewId().getBytes():new byte[0]);
                count = String.valueOf(interceptor.getView().length);
            }
            buf.append(leftfill(local,30," "));
            buf.append(leftfill(startstatus, 10, " "));
            buf.append(leftfill(coord, 30, " "));
            buf.append(leftfill(viewId, 24, " "));
            buf.append(leftfill(count, 8, " "));
            buf.append("\n");
            buf.append("Status:"+status);
            buf.append("\n");
            return buf.toString();
        }
        
        public String getByteString(byte[] b) {
            if ( b == null ) return "{}";
            return Arrays.toString(b,0,Math.min(b.length,4));
        }
        
        public void start() {
            try {
                if ( channel == null ) {
                    channel = createChannel();
                    startstatus = "starting";
                    channel.start(channel.DEFAULT);
                    startstatus = "running";
                } else {
                    status = "Channel already started.";
                }
            } catch ( Exception x ) {
                synchronized (System.err) {
                    System.err.println("Start failed:");
                    StackTraceElement[] els = x.getStackTrace();
                    for (int i = 0; i < els.length; i++) System.err.println(els[i].toString());
                }
                status = "Start failed:"+x.getMessage();
                error = x;
                startstatus = "failed";
                try { channel.stop(GroupChannel.DEFAULT);}catch(Exception ignore){}
                channel = null;
                interceptor = null;
            }
        }
        
        public void stop() {
            try {
                if ( channel != null ) {
                    channel.stop(channel.DEFAULT);
                    status = "Channel Stopped";
                } else {
                    status = "Channel Already Stopped";
                }
            }catch ( Exception x )  {
                synchronized (System.err) {
                    System.err.println("Stop failed:");
                    StackTraceElement[] els = x.getStackTrace();
                    for (int i = 0; i < els.length; i++) System.err.println(els[i].toString());
                }

                status = "Stop failed:"+x.getMessage();
                error = x;
            }finally {
                startstatus = "stopped";
                channel = null;
                interceptor = null;
            }
        }
        
        public GroupChannel createChannel() {
            channel = new GroupChannel();
            ((ReceiverBase)channel.getChannelReceiver()).setAutoBind(100);
            interceptor = new NonBlockingCoordinator() {
                public void fireInterceptorEvent(InterceptorEvent event) {
                    status = event.getEventTypeDesc();
                    int type = event.getEventType();
                    boolean display = VIEW_EVENTS[type];
                    if ( display ) parent.printScreen();
                    try { Thread.sleep(SLEEP_TIME); }catch ( Exception x){}
                }
            };
            channel.addInterceptor(interceptor);
            channel.addInterceptor(new TcpFailureDetector());
            channel.addInterceptor(new MessageDispatch15Interceptor());
            return channel;
        }
    }
}