CamelJdbcColumnNames header missed - spring

Question

I try to use the jdbc component from camel. I found the documentation here: http://camel.apache.org/jdbc.html.
It works well as the result is available from the database but there is no header in the queued answer called CamelJdbcColumnNames as mentioned in the documentation.All i can see is CamelJdbcRowCount. My camel version is 2.15.1.Do i have to turn a switch to enable this?
Here is an extract of my spring-config.xml:
<bean id="ds" class="org.springframework.jdbc.datasource.SimpleDriverDataSource">
<property name="driverClass" value="oracle.jdbc.driver.OracleDriver"/>
<property name="url" value="jdbc:oracle:thin:#myhost:1521:mydbsid"/>
<property name="username" value="myuser"/>
<property name="password" value="mypass"/>
</bean>
<route id="route db">
<from uri="file://data/inbox" />
<to uri="jdbc:ds" />
<to uri="jms:sqlret" />
</route>
EDIT:
To exclude the jms i added a Processor. With this i want to debug the message header. This is a new extract of my spring-config.xml:
<bean id="jdbccheck" class="mypackage.JdbcCheck"></bean>
<route id="route db">
<from uri="file://data/inbox" />
<to uri="jdbc:ds" />
<process ref="jdbccheck"/>
<to uri="jms:sqlret" />
</route>
The Processor code:
public class JdbcCheck implements Processor {
private static final Logger LOG = Logger.getLogger(JdbcCheck.class.getName());
#Override
public void process(Exchange exchange) throws Exception {
LOG.info(exchange.getIn().getHeaders().toString());
}
}
The log message:
{breadcrumbId=ID-chris-HP-50597-1429955241877-0-1, CamelFileAbsolute=false, CamelFileAbsolutePath=C:\daten\chris\source\netbeans\GbLuna\data\inbox2\in.sql, CamelFileContentType=null, CamelFileLastModified=1429953640254, CamelFileLength=36, CamelFileName=in.sql, CamelFileNameConsumed=in.sql, CamelFileNameOnly=in.sql, CamelFileParent=data\inbox2, CamelFilePath=data\inbox2\in.sql, CamelFileRelativePath=in.sql, CamelJdbcRowCount=837}
The last var-/value pair is CamelJdbcRowCount=837 which seems to me that it works somehow. But for further processing i want to deal with the column names. So: how to get CamelJdbcColumnNames?

Answer 1

Ah okay got it now, its because you send the data to a JMS endpoint. And JMS specification only support a number of data types for JMS headers/properties. And that is usually String, numbers and primitive types.
You can read more about this on the Camel JMS documentation page, and from the JMS spec/javadoc.
The column names header is stores as a header of Java collection type and that is not supported by JMS.
http://camel.apache.org/jms
If you enable the Camel tracer you should be able to see the header before the message is routed to the JMS endpoint: http://camel.apache.org/tracer