Question

I am relatively new to Camel and i’ve been struggling with a problem with a simple route that uses MyBatis to “feed” an ActiveMQ queue.

My route is as follows:

public class SearchItemProductionRouteRoute extends SpringRouteBuilder {
    @Override
    public void configure() throws Exception {
        from("timer://pollTheDatabase?delay=5000")
        .to("mybatis:selectSearchItem?statementType=SelectList&consumer.useIterator=true&consumer.onConsume=updateProcessingSearchItem")
        .to("bean:searchItemProcesser?method=process")
        .to("activemq:searchitemqueue");
    }
} 

The mybatis query is working fine. The query itself brings 4 records from the database. My need is that each row should become a message in the queue, but instead, i get 1 message with all the 4 rows in it.

The searchItemProcessor just prints de body of the message (thats how i know that the message contains all 4 records).

These are the queries that the above route uses:

<select id="selectSearchItem" resultMap="result" parameterType="java.util.HashMap">
    SELECT * FROM SEARCH_REQUEST_ITEM SRI WHERE SRI.STATUS = '1' 
</select>

<update id="updateProcessingSearchItem">
    UPDATE SEARCH_REQUEST_ITEM SET STATUS = 2,   
    UPDATEDIN=SYSDATE, UPDATEDBY='XDRBATCH' 
    WHERE ID = #{ID}
</update>

If anyone can shed some light over this i’ll be thankful!

EDIT:

Just found one workaround using the Splitter EIP. First i created this class:

public class XdrMessageSplitterBean {
    @SuppressWarnings({ "rawtypes", "unchecked" })
    public List<HashMap> splitBody(Object body) {
        return (List<HashMap>) body;
    }
}

Then add it to the route:

    public void configure() throws Exception {
        from("timer://pollTheDatabase?delay=5000")
        .to("mybatis:selectSearchItem?statementType=SelectList&consumer.useIterator=true&consumer.onConsume=updateProcessingSearchItem")
        .split().method("xdrMessageSplitterBean", "splitBody")
        .to("bean:searchItemProcesser?method=process")
        .to("activemq:searchitemqueue");
    }

The bean must be declared in the camel-context.xml file:

    <bean id="xdrMessageSplitterBean" name="xdrMessageSplitterBean"
    class="package.of.bean.XdrMessageSplitterBean" />

It works, but does not feel right. If anyone has any suggestion it will be very welcomed.

Answer 1

You can consume from mybatis directly, and specify the polling frequency. You dont need the timer for that. There is a delay option you can use to set = 5000 for 5 seconds frequency.

public void configure() throws Exception {
        from("mybatis:selectSearchItem?statementType=SelectList&consumer.useIterator=true&consumer.onConsume=updateProcessingSearchItem&delay=5000")
        .split().method("xdrMessageSplitterBean", "splitBody")
        .to("bean:searchItemProcesser?method=process")
        .to("activemq:searchitemqueue");
    }