Avoiding duplicated messages on JMS/ActiveMQ

Question

Is there a way to suppress duplicated messages on a queue defined on ActiveMQ server?

I tried to define manually JMSMessageID, (message.setJMSMessageID(\"uniqueid\")

Answer 1

There is a way to make ActiveMQ to filter duplicates based on a JMS property. it involves writing an Activemq Plugin. A basic broker filter that sends duplicate messages to the deadletter queue would be like this

import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.activemq.broker.Broker;
import org.apache.activemq.command.Message;
import org.apache.activemq.command.ActiveMQMessage;
import org.apache.activemq.broker.BrokerFilter;
import org.apache.activemq.broker.ConnectionContext;
import org.apache.activemq.command.ConnectionInfo;
import org.apache.activemq.broker.ProducerBrokerExchange;

public class DuplicateFilterBroker extends BrokerFilter {
    String messagePropertyName;
    boolean switchValue;

    public DuplicateFilterBroker(Broker next, String messagePropertyName) {
        super(next);
        this.messagePropertyName = messagePropertyName;
    }

    public boolean hasDuplicate(String propertyValue){
        switchValue = propertyValue;
        return switchValue;
    }

    public void send(ProducerBrokerExchange producerExchange, Message msg) throws Exception { 
        ActiveMQMessage amqmsg = (ActiveMQMessage)msg; 
        Object msgObj = msg.getMessage(); 
        if (msgObj instanceof javax.jms.Message) { 
            javax.jms.Message jmsMsg = (javax.jms.Message) msgObj; 
            if (!hasDuplicate(jmsMsg.getStringProperty(messagePropertyName))) {
                super.send(producerExchange, msg);
            }
            else {
               sendToDeadLetterQueue(producerExchange.getConnectionContext(), msg);
            } 
        }
    }  
}