CODEWITHSUNDEEP
databasemule
BreenDeen
BreenDeen

Reputation: 760

Mule DB Component returning ResultsetIterator or List<Map<String,Object>

The data type returned by the Mule enricher when wrapped display very strange behaviour. It returns a ResultSetIterator in some situations and List at other times. I have the exact same configuration in a flow being the only difference i.e. here it is a sub-flow. Does the return type behave differently when the database component in an enricher is in a subflow than if in a flow?

<sub-flow name="process.customer">
    <enricher target="#[variable:customers]"
        doc:name="Customer Enrichment">
        <db:select config-ref="MySQLConfig"
                doc:name="Customer Query"
                fetchSize="3000" streaming="true">
                <db:parameterized-query><![CDATA[
                SELECT * FROM CUSTOMER WHERE STATUS='ACTIVE'
                ]]></db:parameterized-query>
            </db:select>
    </enricher>
    <custom-transformer class="com.gdc.transformer.CustomerTransformer" />
    <vm:outbound-endpoint exchange-pattern="one-way"

    public class CustomerTransformer extends AabstractMessageTransformer{

       @Override
        public Object transformMessage(MuleMessage message, String 
         outputEncoding) throws TransformerException {
            //Throws ClassCastException i.e. cannot cast ResultSetIterator to 
            // LinkedList       
           List<Map<String,Object>> r=     
              message.getInvocationProperty("customers"));
         ....

       }
    }

Upvotes: 0

Views: 241

Answers (2)

vijay dhanakodi
vijay dhanakodi

Reputation: 175

Breen,

If you want your output as List if Maps then disable Streaming=false else you need your output as iterable object then make the attribute as true.

Upvotes: 0

Clinton Murdoch
Clinton Murdoch

Reputation: 453

When using streaming="true" on the db:select component, you will get a ResultSetIterator. In this case you also have fetchSize="3000", so it will attempt to select 3000 records at a time. With streaming="false", you will get a List with all of the applicable records loaded in one go.

Upvotes: 0

Related Questions