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ActiveMQ example source code file (MasterConnector.java)

This example ActiveMQ source code file (MasterConnector.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 - ActiveMQ tags/keywords

atomicboolean, atomicboolean, brokerinfo, defaulttransportlistener, exception, exception, io, ioexception, masterconnector, masterconnector, net, network, servicestopper, slave, string, uri, uri, util

The ActiveMQ MasterConnector.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.activemq.broker.ft;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.activemq.Service;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.broker.BrokerServiceAware;
import org.apache.activemq.broker.TransportConnector;
import org.apache.activemq.command.BrokerInfo;
import org.apache.activemq.command.Command;
import org.apache.activemq.command.CommandTypes;
import org.apache.activemq.command.ConnectionId;
import org.apache.activemq.command.ConnectionInfo;
import org.apache.activemq.command.MessageDispatch;
import org.apache.activemq.command.ProducerInfo;
import org.apache.activemq.command.Response;
import org.apache.activemq.command.SessionInfo;
import org.apache.activemq.command.ShutdownInfo;
import org.apache.activemq.transport.DefaultTransportListener;
import org.apache.activemq.transport.Transport;
import org.apache.activemq.transport.TransportDisposedIOException;
import org.apache.activemq.transport.TransportFactory;
import org.apache.activemq.util.IdGenerator;
import org.apache.activemq.util.ServiceStopper;
import org.apache.activemq.util.ServiceSupport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Connects a Slave Broker to a Master when using <a
 * href="http://activemq.apache.org/masterslave.html">Master Slave</a> for High
 * Availability of messages.
 * 
 * @org.apache.xbean.XBean
 * 
 */
public class MasterConnector implements Service, BrokerServiceAware {

    private static final Logger LOG = LoggerFactory.getLogger(MasterConnector.class);
    private BrokerService broker;
    private URI remoteURI;
    private URI localURI;
    private Transport localBroker;
    private Transport remoteBroker;
    private TransportConnector connector;
    private AtomicBoolean started = new AtomicBoolean(false);
    private AtomicBoolean stoppedBeforeStart = new AtomicBoolean(false);
    private final IdGenerator idGenerator = new IdGenerator();
    private String userName;
    private String password;
    private ConnectionInfo connectionInfo;
    private SessionInfo sessionInfo;
    private ProducerInfo producerInfo;
    private final AtomicBoolean masterActive = new AtomicBoolean();
    private BrokerInfo brokerInfo;
    private boolean firstConnection=true;
    private boolean failedToStart;

    public MasterConnector() {
    }

    public MasterConnector(String remoteUri) throws URISyntaxException {
        remoteURI = new URI(remoteUri);
    }

    public void setBrokerService(BrokerService broker) {
        this.broker = broker;
        if (localURI == null) {
            localURI = broker.getVmConnectorURI();
        }
        if (connector == null) {
            List transportConnectors = broker.getTransportConnectors();
            if (!transportConnectors.isEmpty()) {
                connector = (TransportConnector)transportConnectors.get(0);
            }
        }
    }

    public boolean isSlave() {
        return masterActive.get();
    }

    protected void restartBridge() throws Exception {
        localBroker.oneway(connectionInfo);
        remoteBroker.oneway(connectionInfo);
        localBroker.oneway(sessionInfo);
        remoteBroker.oneway(sessionInfo);
        remoteBroker.oneway(producerInfo);
        remoteBroker.oneway(brokerInfo);
    }
    
    public void start() throws Exception {
        if (!started.compareAndSet(false, true)) {
            return;
        }
        if (remoteURI == null) {
            throw new IllegalArgumentException("You must specify a remoteURI");
        }
        localBroker = TransportFactory.connect(localURI);
        remoteBroker = TransportFactory.connect(remoteURI);
        LOG.info("Starting a slave connection between " + localBroker + " and " + remoteBroker);
        localBroker.setTransportListener(new DefaultTransportListener() {

            public void onCommand(Object command) {
            }

            public void onException(IOException error) {
                if (started.get()) {
                    serviceLocalException(error);
                }
            }
        });
        remoteBroker.setTransportListener(new DefaultTransportListener() {

            public void onCommand(Object o) {
                Command command = (Command)o;
                if (started.get()) {
                    serviceRemoteCommand(command);
                }
            }

            public void onException(IOException error) {
                if (started.get()) {
                    serviceRemoteException(error);
                }
            }
            
            public void transportResumed() {
            	try{
            		if(!firstConnection){
	            		localBroker = TransportFactory.connect(localURI);
	            		localBroker.setTransportListener(new DefaultTransportListener() {
	
	                        public void onCommand(Object command) {
	                        }
	
	                        public void onException(IOException error) {
	                            if (started.get()) {
	                                serviceLocalException(error);
	                            }
	                        }
	                    });
	            		localBroker.start();
	            		restartBridge();
	            		LOG.info("Slave connection between " + localBroker + " and " + remoteBroker + " has been reestablished.");
            		}else{
            			firstConnection=false;
            		}
            	}catch(IOException e){
            		LOG.error("MasterConnector failed to send BrokerInfo in transportResumed:", e);
            	}catch(Exception e){
            		LOG.error("MasterConnector failed to restart localBroker in transportResumed:", e);
            	}
            	
            }
        });
        try {
            localBroker.start();
            remoteBroker.start();
            startBridge();
            masterActive.set(true);
        } catch (Exception e) {
            masterActive.set(false);
            if(!stoppedBeforeStart.get()){
            	LOG.error("Failed to start network bridge: " + e, e);
            }else{
            	LOG.info("Slave stopped before connected to the master.");
            }
            setFailedToStart(true);
        }    
    }

    protected void startBridge() throws Exception {
        connectionInfo = new ConnectionInfo();
        connectionInfo.setConnectionId(new ConnectionId(idGenerator.generateId()));
        connectionInfo.setClientId(idGenerator.generateId());
        connectionInfo.setUserName(userName);
        connectionInfo.setPassword(password);
        connectionInfo.setBrokerMasterConnector(true);
        sessionInfo = new SessionInfo(connectionInfo, 1);
        producerInfo = new ProducerInfo(sessionInfo, 1);
        producerInfo.setResponseRequired(false);
        if (connector != null) {
            brokerInfo = connector.getBrokerInfo();
        } else {
            brokerInfo = new BrokerInfo();
        }
        brokerInfo.setBrokerName(broker.getBrokerName());
        brokerInfo.setPeerBrokerInfos(broker.getBroker().getPeerBrokerInfos());
        brokerInfo.setSlaveBroker(true);
        brokerInfo.setPassiveSlave(broker.isPassiveSlave());
        restartBridge();
        LOG.info("Slave connection between " + localBroker + " and " + remoteBroker + " has been established.");
    }

    public void stop() throws Exception {
        if (!started.compareAndSet(true, false)||!masterActive.get()) {
            return;
        }
        masterActive.set(false);
        try {
            // if (connectionInfo!=null){
            // localBroker.request(connectionInfo.createRemoveCommand());
            // }
            // localBroker.setTransportListener(null);
            // remoteBroker.setTransportListener(null);
            remoteBroker.oneway(new ShutdownInfo());
            localBroker.oneway(new ShutdownInfo());
        } catch (IOException e) {
            LOG.debug("Caught exception stopping", e);
        } finally {
            ServiceStopper ss = new ServiceStopper();
            ss.stop(localBroker);
            ss.stop(remoteBroker);
            ss.throwFirstException();
        }
    }
    
    public void stopBeforeConnected()throws Exception{
        masterActive.set(false);
        started.set(false);
        stoppedBeforeStart.set(true);
        ServiceStopper ss = new ServiceStopper();
        ss.stop(localBroker);
        ss.stop(remoteBroker);
    }

    protected void serviceRemoteException(IOException error) {
        LOG.error("Network connection between " + localBroker + " and " + remoteBroker + " shutdown: " + error.getMessage(), error);
        shutDown();
    }

    protected void serviceRemoteCommand(Command command) {
        try {
            if (command.isMessageDispatch()) {
                MessageDispatch md = (MessageDispatch)command;
                command = md.getMessage();
            }
            if (command.getDataStructureType() == CommandTypes.SHUTDOWN_INFO) {
                LOG.warn("The Master has shutdown");
                shutDown();
            } else {
                boolean responseRequired = command.isResponseRequired();
                int commandId = command.getCommandId();
                if (responseRequired) {
                    Response response = (Response)localBroker.request(command);
                    response.setCorrelationId(commandId);
                    remoteBroker.oneway(response);
                } else {
                    localBroker.oneway(command);
                }
            }
        } catch (IOException e) {
            serviceRemoteException(e);
        }
    }

    protected void serviceLocalException(Throwable error) {
    	if (!(error instanceof TransportDisposedIOException) || localBroker.isDisposed()){
	        LOG.info("Network connection between " + localBroker + " and " + remoteBroker + " shutdown: " + error.getMessage(), error);
	        ServiceSupport.dispose(this);
    	}else{
    		LOG.info(error.getMessage());
    	}
    }

    /**
     * @return Returns the localURI.
     */
    public URI getLocalURI() {
        return localURI;
    }

    /**
     * @param localURI The localURI to set.
     */
    public void setLocalURI(URI localURI) {
        this.localURI = localURI;
    }

    /**
     * @return Returns the remoteURI.
     */
    public URI getRemoteURI() {
        return remoteURI;
    }

    /**
     * @param remoteURI The remoteURI to set.
     */
    public void setRemoteURI(URI remoteURI) {
        this.remoteURI = remoteURI;
    }

    /**
     * @return Returns the password.
     */
    public String getPassword() {
        return password;
    }

    /**
     * @param password The password to set.
     */
    public void setPassword(String password) {
        this.password = password;
    }

    /**
     * @return Returns the userName.
     */
    public String getUserName() {
        return userName;
    }

    /**
     * @param userName The userName to set.
     */
    public void setUserName(String userName) {
        this.userName = userName;
    }

    private void shutDown() {
        masterActive.set(false);
        broker.masterFailed();
        ServiceSupport.dispose(this);
    }

	public boolean isStoppedBeforeStart() {
		return stoppedBeforeStart.get();
	}

    /**
     * Get the failedToStart
     * @return the failedToStart
     */
    public boolean isFailedToStart() {
        return this.failedToStart;
    }

    /**
     * Set the failedToStart
     * @param failedToStart the failedToStart to set
     */
    public void setFailedToStart(boolean failedToStart) {
        this.failedToStart = failedToStart;
    }

}

Other ActiveMQ examples (source code examples)

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