mcastservice.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 * 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</b> 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: 467222 $, $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
 */


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>&lt;description&gt;/&lt;version&gt;</code>.
     */
    public String getInfo() {
        return (info);
    }
    
    /**
     *
     * @param properties
     * <BR/>All are required<BR />
     * 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));
    }

    /**
     * @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();
    }