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ActiveMQ example source code file (AbstractSubscription.java)

This example ActiveMQ source code file (AbstractSubscription.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

abstractsubscription, booleanexpression, booleanexpression, connectioncontext, consumerinfo, consumerinfo, copyonwritearraylist, exception, exception, invalidselectorexception, invalidselectorexception, io, ioexception, management, messageevaluationcontext, objectname, threading, threads, util

The ActiveMQ AbstractSubscription.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.region;

import java.io.IOException;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import javax.jms.InvalidSelectorException;
import javax.jms.JMSException;
import javax.management.ObjectName;
import org.apache.activemq.broker.Broker;
import org.apache.activemq.broker.ConnectionContext;
import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ConsumerId;
import org.apache.activemq.command.ConsumerInfo;
import org.apache.activemq.filter.BooleanExpression;
import org.apache.activemq.filter.DestinationFilter;
import org.apache.activemq.filter.LogicExpression;
import org.apache.activemq.filter.MessageEvaluationContext;
import org.apache.activemq.filter.NoLocalExpression;
import org.apache.activemq.selector.SelectorParser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public abstract class AbstractSubscription implements Subscription {

    private static final Logger LOG = LoggerFactory.getLogger(AbstractSubscription.class);
    protected Broker broker;
    protected ConnectionContext context;
    protected ConsumerInfo info;
    protected final DestinationFilter destinationFilter;
    protected final CopyOnWriteArrayList<Destination> destinations = new CopyOnWriteArrayList();
    private BooleanExpression selectorExpression;
    private ObjectName objectName;
    private int cursorMemoryHighWaterMark = 70;
    private boolean slowConsumer;


    public AbstractSubscription(Broker broker,ConnectionContext context, ConsumerInfo info) throws InvalidSelectorException {
        this.broker = broker;
        this.context = context;
        this.info = info;
        this.destinationFilter = DestinationFilter.parseFilter(info.getDestination());
        this.selectorExpression = parseSelector(info);
    }

    private static BooleanExpression parseSelector(ConsumerInfo info) throws InvalidSelectorException {
        BooleanExpression rc = null;
        if (info.getSelector() != null) {
            rc = SelectorParser.parse(info.getSelector());
        }
        if (info.isNoLocal()) {
            if (rc == null) {
                rc = new NoLocalExpression(info.getConsumerId().getConnectionId());
            } else {
                rc = LogicExpression.createAND(new NoLocalExpression(info.getConsumerId().getConnectionId()), rc);
            }
        }
        if (info.getAdditionalPredicate() != null) {
            if (rc == null) {
                rc = info.getAdditionalPredicate();
            } else {
                rc = LogicExpression.createAND(info.getAdditionalPredicate(), rc);
            }
        }
        return rc;
    }

    public boolean matches(MessageReference node, MessageEvaluationContext context) throws IOException {
        ConsumerId targetConsumerId = node.getTargetConsumerId();
        if (targetConsumerId != null) {
            if (!targetConsumerId.equals(info.getConsumerId())) {
                return false;
            }
        }
        try {
            return (selectorExpression == null || selectorExpression.matches(context)) && this.context.isAllowedToConsume(node);
        } catch (JMSException e) {
            LOG.info("Selector failed to evaluate: " + e.getMessage(), e);
            return false;
        }
    }

    public boolean matches(ActiveMQDestination destination) {
        return destinationFilter.matches(destination);
    }

    public void add(ConnectionContext context, Destination destination) throws Exception {
        destinations.add(destination);
    }

    public List<MessageReference> remove(ConnectionContext context, Destination destination) throws Exception {
        destinations.remove(destination);
        return Collections.EMPTY_LIST;
    }

    public ConsumerInfo getConsumerInfo() {
        return info;
    }

    public void gc() {
    }

    public boolean isSlave() {
        return broker.getBrokerService().isSlave();
    }

    public ConnectionContext getContext() {
        return context;
    }

    public ConsumerInfo getInfo() {
        return info;
    }

    public BooleanExpression getSelectorExpression() {
        return selectorExpression;
    }

    public String getSelector() {
        return info.getSelector();
    }

    public void setSelector(String selector) throws InvalidSelectorException {
        ConsumerInfo copy = info.copy();
        copy.setSelector(selector);
        BooleanExpression newSelector = parseSelector(copy);
        // its valid so lets actually update it now
        info.setSelector(selector);
        this.selectorExpression = newSelector;
    }

    public ObjectName getObjectName() {
        return objectName;
    }

    public void setObjectName(ObjectName objectName) {
        this.objectName = objectName;
    }

    public int getPrefetchSize() {
        return info.getPrefetchSize();
    }
    public void setPrefetchSize(int newSize) {
        info.setPrefetchSize(newSize);
    }

    public boolean isRecoveryRequired() {
        return true;
    }
    
    public boolean isSlowConsumer() {
        return slowConsumer;
    }
    
    public void setSlowConsumer(boolean val) {
        slowConsumer = val;
    }

    public boolean addRecoveredMessage(ConnectionContext context, MessageReference message) throws Exception {
        boolean result = false;
        MessageEvaluationContext msgContext = context.getMessageEvaluationContext();
        try {
            msgContext.setDestination(message.getRegionDestination().getActiveMQDestination());
            msgContext.setMessageReference(message);
            result = matches(message, msgContext);
            if (result) {
                doAddRecoveredMessage(message);
            }

        } finally {
            msgContext.clear();
        }
        return result;
    }

    public ActiveMQDestination getActiveMQDestination() {
        return info != null ? info.getDestination() : null;
    }
    
    public boolean isBrowser() {
        return info != null && info.isBrowser();
    }
    
    public int getInFlightUsage() {
        if (info.getPrefetchSize() > 0) {
        return (getInFlightSize() * 100)/info.getPrefetchSize();
        }
        return Integer.MAX_VALUE;
    }
    
    /**
     * Add a destination
     * @param destination
     */
    public void addDestination(Destination destination) {
        
    }
       
    
    /**
     * Remove a destination
     * @param destination
     */
    public void removeDestination(Destination destination) {
        
    }
    
    public int getCursorMemoryHighWaterMark(){
    	return this.cursorMemoryHighWaterMark;
    }

	public void setCursorMemoryHighWaterMark(int cursorMemoryHighWaterMark){
		this.cursorMemoryHighWaterMark=cursorMemoryHighWaterMark;
	}
    
    public int countBeforeFull() {
        return getDispatchedQueueSize() - info.getPrefetchSize();
    }

    public void unmatched(MessageReference node) throws IOException {
        // only durable topic subs have something to do here
    }

    protected void doAddRecoveredMessage(MessageReference message) throws Exception {
        add(message);
    }
}

Other ActiveMQ examples (source code examples)

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