Tomcat example source code file (McastService.java)

This example Tomcat source code file (McastService.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

exception, exception, illegalargumentexception, io, ioexception, mcastservice, mcastservice, member, member, memberimpl, membershipservice,membershiplistener, properties, string, string, unable, util

The Tomcat McastService.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.membership;

import java.util.Properties;

import org.apache.catalina.tribes.Member;
import org.apache.catalina.tribes.MembershipListener;
import org.apache.catalina.tribes.MembershipService;
import org.apache.catalina.tribes.util.StringManager;
import org.apache.catalina.tribes.util.UUIDGenerator;
import java.io.IOException;

/**
 * A <b>membership implementation using simple multicast.
 * This is the representation of a multicast membership service.
 * This class is responsible for maintaining a list of active cluster nodes in the cluster.
 * If a node fails to send out a heartbeat, the node will be dismissed.
 *
 * @author Filip Hanik
 * @version $Revision: 567472 $, $Date: 2007-08-19 23:12:31 +0200 (dim., 19 août 2007) $
 */


public class McastService implements MembershipService,MembershipListener {

    private static org.apache.juli.logging.Log log =
        org.apache.juli.logging.LogFactory.getLog( McastService.class );

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

    /**
     * The descriptive information about this implementation.
     */
    private static final String info = "McastService/2.1";

    /**
     * The implementation specific properties
     */
    protected Properties properties = new Properties();
    /**
     * A handle to the actual low level implementation
     */
    protected McastServiceImpl impl;
    /**
     * A membership listener delegate (should be the cluster :)
     */
    protected MembershipListener listener;
    /**
     * The local member
     */
    protected MemberImpl localMember ;
    private int mcastSoTimeout;
    private int mcastTTL;
    
    protected byte[] payload;
    
    protected byte[] domain;

    /**
     * Create a membership service.
     */
    public McastService() {
        //default values
        properties.setProperty("mcastPort","45564");
        properties.setProperty("mcastAddress","228.0.0.4");
        properties.setProperty("memberDropTime","3000");
        properties.setProperty("mcastFrequency","500");

    }

    /**
     * Return descriptive information about this implementation and the
     * corresponding version number, in the format
     * <code><description>/<version>.
     */
    public String getInfo() {
        return (info);
    }
    
    /**
     *
     * @param properties
     * <BR/>All are required

     * 1. mcastPort - the port to listen to<BR>
     * 2. mcastAddress - the mcast group address<BR>
     * 4. bindAddress - the bind address if any - only one that can be null<BR>
     * 5. memberDropTime - the time a member is gone before it is considered gone.<BR>
     * 6. mcastFrequency - the frequency of sending messages<BR>
     * 7. tcpListenPort - the port this member listens to<BR>
     * 8. tcpListenHost - the bind address of this member<BR>
     * @exception java.lang.IllegalArgumentException if a property is missing.
     */
    public void setProperties(Properties properties) {
        hasProperty(properties,"mcastPort");
        hasProperty(properties,"mcastAddress");
        hasProperty(properties,"memberDropTime");
        hasProperty(properties,"mcastFrequency");
        hasProperty(properties,"tcpListenPort");
        hasProperty(properties,"tcpListenHost");
        this.properties = properties;
    }

    /**
     * Return the properties, see setProperties
     */
    public Properties getProperties() {
        return properties;
    }

    /**
     * Return the local member name
     */
    public String getLocalMemberName() {
        return localMember.toString() ;
    }
 
    /**
     * Return the local member
     */
    public Member getLocalMember(boolean alive) {
        if ( alive && localMember != null && impl != null) localMember.setMemberAliveTime(System.currentTimeMillis()-impl.getServiceStartTime());
        return localMember;
    }
    
    /**
     * Sets the local member properties for broadcasting
     */
    public void setLocalMemberProperties(String listenHost, int listenPort) {
        properties.setProperty("tcpListenHost",listenHost);
        properties.setProperty("tcpListenPort",String.valueOf(listenPort));
        try {
            if (localMember != null) {
                localMember.setHostname(listenHost);
                localMember.setPort(listenPort);
            } else {
                localMember = new MemberImpl(listenHost, listenPort, 0);
                localMember.setUniqueId(UUIDGenerator.randomUUID(true));
                localMember.setPayload(getPayload());
                localMember.setDomain(getDomain());
            }
            localMember.getData(true, true);
        }catch ( IOException x ) {
            throw new IllegalArgumentException(x);
        }
    }
    
    public void setAddress(String addr) {
        properties.setProperty("mcastAddress", addr);
    }
    
    /**
     * @deprecated use setAddress
     * @param addr String
     */
    public void setMcastAddr(String addr) {
        setAddress(addr);
    }
    
    public String getAddress() {
        return properties.getProperty("mcastAddress");
    }
    
    /**
     * @deprecated use getAddress
     * @return String
     */
    public String getMcastAddr() {
        return getAddress();
    }

    public void setMcastBindAddress(String bindaddr) {
        setBind(bindaddr);
    }
    
    public void setBind(String bindaddr) {
        properties.setProperty("mcastBindAddress", bindaddr);
    }
    /**
     * @deprecated use getBind
     * @return String
     */
    public String getMcastBindAddress() {
        return getBind();
    }

    public String getBind() {
        return properties.getProperty("mcastBindAddress");
    }

    /**
     * @deprecated use setPort
     * @param port int
     */
    public void setMcastPort(int port) {
        setPort(port);
    }

    public void setPort(int port) {
        properties.setProperty("mcastPort", String.valueOf(port));
    }
    
    public void setRecoveryCounter(int recoveryCounter) {
        properties.setProperty("recoveryCounter", String.valueOf(recoveryCounter));
    }

    public void setRecoveryEnabled(boolean recoveryEnabled) {
        properties.setProperty("recoveryEnabled", String.valueOf(recoveryEnabled));
    }

    public void setRecoverySleepTime(long recoverySleepTime) {
        properties.setProperty("recoverySleepTime", String.valueOf(recoverySleepTime));
    }


    /**
     * @deprecated use getPort()
     * @return int
     */
    public int getMcastPort() {
        return getPort();
    }
    public int getPort() {
        String p = properties.getProperty("mcastPort");
        return new Integer(p).intValue();
    }
    
    /**
     * @deprecated use setFrequency
     * @param time long
     */
    public void setMcastFrequency(long time) {
        setFrequency(time);
    }
    
    public void setFrequency(long time) {
        properties.setProperty("mcastFrequency", String.valueOf(time));
    }

    /**
     * @deprecated use getFrequency
     * @return long
     */
    public long getMcastFrequency() {
        return getFrequency();
    }

    public long getFrequency() {
        String p = properties.getProperty("mcastFrequency");
        return new Long(p).longValue();
    }

    public void setMcastDropTime(long time) {
        setDropTime(time);
    }
    public void setDropTime(long time) {
        properties.setProperty("memberDropTime", String.valueOf(time));
    }
    
    /**
     * @deprecated use getDropTime
     * @return long
     */
    public long getMcastDropTime() {
        return getDropTime();
    }

    public long getDropTime() {
        String p = properties.getProperty("memberDropTime");
        return new Long(p).longValue();
    }

    /**
     * Check if a required property is available.
     * @param properties The set of properties
     * @param name The property to check for
     */
    protected void hasProperty(Properties properties, String name){
        if ( properties.getProperty(name)==null) throw new IllegalArgumentException("McastService:Required property \""+name+"\" is missing.");
    }

    /**
     * Start broadcasting and listening to membership pings
     * @throws java.lang.Exception if a IO error occurs
     */
    public void start() throws java.lang.Exception {
        start(MembershipService.MBR_RX);
        start(MembershipService.MBR_TX);
    }
    
    public void start(int level) throws java.lang.Exception {
        hasProperty(properties,"mcastPort");
        hasProperty(properties,"mcastAddress");
        hasProperty(properties,"memberDropTime");
        hasProperty(properties,"mcastFrequency");
        hasProperty(properties,"tcpListenPort");
        hasProperty(properties,"tcpListenHost");

        if ( impl != null ) {
            impl.start(level);
            return;
        }
        String host = getProperties().getProperty("tcpListenHost");
        int port = Integer.parseInt(getProperties().getProperty("tcpListenPort"));
        
        if ( localMember == null ) {
            localMember = new MemberImpl(host, port, 100);
            localMember.setUniqueId(UUIDGenerator.randomUUID(true));
        } else {
            localMember.setHostname(host);
            localMember.setPort(port);
            localMember.setMemberAliveTime(100);
        }
        if ( this.payload != null ) localMember.setPayload(payload);
        if ( this.domain != null ) localMember.setDomain(domain);
        localMember.setServiceStartTime(System.currentTimeMillis());
        java.net.InetAddress bind = null;
        if ( properties.getProperty("mcastBindAddress")!= null ) {
            bind = java.net.InetAddress.getByName(properties.getProperty("mcastBindAddress"));
        }
        int ttl = -1;
        int soTimeout = -1;
        if ( properties.getProperty("mcastTTL") != null ) {
            try {
                ttl = Integer.parseInt(properties.getProperty("mcastTTL"));
            } catch ( Exception x ) {
                log.error("Unable to parse mcastTTL="+properties.getProperty("mcastTTL"),x);
            }
        }
        if ( properties.getProperty("mcastSoTimeout") != null ) {
            try {
                soTimeout = Integer.parseInt(properties.getProperty("mcastSoTimeout"));
            } catch ( Exception x ) {
                log.error("Unable to parse mcastSoTimeout="+properties.getProperty("mcastSoTimeout"),x);
            }
        }

        impl = new McastServiceImpl((MemberImpl)localMember,Long.parseLong(properties.getProperty("mcastFrequency")),
                                    Long.parseLong(properties.getProperty("memberDropTime")),
                                    Integer.parseInt(properties.getProperty("mcastPort")),
                                    bind,
                                    java.net.InetAddress.getByName(properties.getProperty("mcastAddress")),
                                    ttl,
                                    soTimeout,
                                    this);
        String value = properties.getProperty("recoveryEnabled","true");
        boolean recEnabled = Boolean.valueOf(value).booleanValue() ;
        impl.setRecoveryEnabled(recEnabled);        
        int recCnt = Integer.parseInt(properties.getProperty("recoveryCounter","10"));
        impl.setRecoveryCounter(recCnt);
        long recSlpTime = Long.parseLong(properties.getProperty("recoverySleepTime","5000"));
        impl.setRecoverySleepTime(recSlpTime);
        
        
        impl.start(level);
		

    }

 
    /**
     * Stop broadcasting and listening to membership pings
     */
    public void stop(int svc) {
        try  {
            if ( impl != null && impl.stop(svc) ) impl = null;
        } catch ( Exception x)  {
            log.error("Unable to stop the mcast service, level:"+svc+".",x);
        }
    }


    /**
     * Return all the members by name
     */
    public String[] getMembersByName() {
        Member[] currentMembers = getMembers();
        String [] membernames ;
        if(currentMembers != null) {
            membernames = new String[currentMembers.length];
            for (int i = 0; i < currentMembers.length; i++) {
                membernames[i] = currentMembers[i].toString() ;
            }
        } else
            membernames = new String[0] ;
        return membernames ;
    }
 
    /**
     * Return the member by name
     */
    public Member findMemberByName(String name) {
        Member[] currentMembers = getMembers();
        for (int i = 0; i < currentMembers.length; i++) {
            if (name.equals(currentMembers[i].toString()))
                return currentMembers[i];
        }
        return null;
    }

    /**
     * has members?
     */
    public boolean hasMembers() {
       if ( impl == null || impl.membership == null ) return false;
       return impl.membership.hasMembers();
    }
    
    public Member getMember(Member mbr) {
        if ( impl == null || impl.membership == null ) return null;
        return impl.membership.getMember(mbr);
    }

    /**
     * Return all the members
     */
    protected static final Member[]EMPTY_MEMBERS = new Member[0];
    public Member[] getMembers() {
        if ( impl == null || impl.membership == null ) return EMPTY_MEMBERS;
        return impl.membership.getMembers();
    }
    /**
     * Add a membership listener, this version only supports one listener per service,
     * so calling this method twice will result in only the second listener being active.
     * @param listener The listener
     */
    public void setMembershipListener(MembershipListener listener) {
        this.listener = listener;
    }
    /**
     * Remove the membership listener
     */
    public void removeMembershipListener(){
        listener = null;
    }

    public void memberAdded(Member member) {
        if ( listener!=null ) listener.memberAdded(member);
    }

    /**
     * Callback from the impl when a new member has been received
     * @param member The member
     */
    public void memberDisappeared(Member member)
    {
        if ( listener!=null ) listener.memberDisappeared(member);
    }

    /**
     * @deprecated use getSoTimeout
     * @return int
     */
    public int getMcastSoTimeout() {
        return getSoTimeout();
    }
    
    public int getSoTimeout() {
        return mcastSoTimeout;
    }
    
    /**
     * @deprecated use setSoTimeout
     * @param mcastSoTimeout int
     */
    public void setMcastSoTimeout(int mcastSoTimeout) {
        setSoTimeout(mcastSoTimeout);
    }
    
    public void setSoTimeout(int mcastSoTimeout) {
        this.mcastSoTimeout = mcastSoTimeout;
        properties.setProperty("mcastSoTimeout", String.valueOf(mcastSoTimeout));
    }
    
    /**
     * @deprecated use getTtl
     * @return int
     */
    public int getMcastTTL() {
        return getTtl();
    }
    
    public int getTtl() {
        return mcastTTL;
    }

    public byte[] getPayload() {
        return payload;
    }
    
    public byte[] getDomain() {
        return domain;
    }
    
    /**
     * @deprecated use setTtl
     * @param mcastTTL int
     */
    public void setMcastTTL(int mcastTTL) {
        setTtl(mcastTTL);
    }

    public void setTtl(int mcastTTL) {
        this.mcastTTL = mcastTTL;
        properties.setProperty("mcastTTL", String.valueOf(mcastTTL));
    }

    public void setPayload(byte[] payload) {
        this.payload = payload;
        if ( localMember != null ) {
            localMember.setPayload(payload);
            localMember.getData(true,true);
            try {
                if (impl != null) impl.send(false);
            }catch ( Exception x ) {
                log.error("Unable to send payload update.",x);
            }
        }
    }
    
    public void setDomain(byte[] domain) {
        this.domain = domain;
        if ( localMember != null ) {
            localMember.setDomain(domain);
            localMember.getData(true,true);
            try {
                if (impl != null) impl.send(false);
            }catch ( Exception x ) {
                log.error("Unable to send domain update.",x);
            }
        }
    }

    /**
     * Simple test program
     * @param args Command-line arguments
     * @throws Exception If an error occurs
     */
    public static void main(String args[]) throws Exception {
		if(log.isInfoEnabled())
            log.info("Usage McastService hostname tcpport");
        McastService service = new McastService();
        java.util.Properties p = new java.util.Properties();
        p.setProperty("mcastPort","5555");
        p.setProperty("mcastAddress","224.10.10.10");
        p.setProperty("mcastClusterDomain","catalina");
        p.setProperty("bindAddress","localhost");
        p.setProperty("memberDropTime","3000");
        p.setProperty("mcastFrequency","500");
        p.setProperty("tcpListenPort","4000");
        p.setProperty("tcpListenHost","127.0.0.1");
        service.setProperties(p);
        service.start();
        Thread.sleep(60*1000*60);
    }
}