6.2. Provider Marshalers
Overview
Providers use an implementation of the
org.apache.servicemix.jms.endpoints.JmsProviderMarshaler interface to convert normalized messages into JMS messages. The marshaler also converts the incoming reply from a JMS message into a normalized message. The JMS binding component comes with two provider marshaler implementations:
DefaultProviderMarshaler- The
DefaultProviderMarshalerclass provides the marshaler used by generic provider endpoints. JmsSoapProviderMarshaler- The
JmsSoapProviderMarshalerclass provides the marshaler used by SOAP provider endpoints.NoteThe default SOAP marshaler does not support the full range of SOAP messages nor does it support marshaling map based messages into JMS messages.
When the default provider marshalers do not suffice for your application, you can provide a custom implementation of the
JmsProviderMarshaler interface.
Implementing the marshaler
To create a custom provider marshaler, you implement the
org.apache.servicemix.jms.endpoints.JmsProviderMarshaler interface. The JmsProviderMarshaler interface, shown in Example 6.4, “The Provider Marshaler Interface”, has two methods you need to implement:
Example 6.4. The Provider Marshaler Interface
public interface JmsProviderMarshaler
{
Message createMessage(MessageExchange exchange, NormalizedMessage in, Session session) throws Exception;
void populateMessage(Message message, MessageExchange exchange, NormalizedMessage normalizedMessage) throws Exception;
}createMessage()- The
createMessage()method uses information from the Red Hat JBoss Fuse core to generate a JMS message. Its parameters include the message exchange, the normalized message that is received by the provider, and the active JMS session. populateMessage()- The
populateMessage()method takes a JMS message and adds it to a message exchange for use by the Red Hat JBoss Fuse core.
Example 6.5, “Provider Marshaler Implementation” shows a simple provider marshaler implementation.
Example 6.5. Provider Marshaler Implementation
package com.widgetVendor.example;
import javax.jbi.messaging.MessageExchange;
import javax.jbi.messaging.NormalizedMessage;
import javax.jms.Message;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.xml.transform.Source;
import org.apache.servicemix.jbi.jaxp.SourceTransformer;
import org.apache.servicemix.jbi.jaxp.StringSource;
import org.apache.servicemix.jms.endpoints.JmsProviderMarshaler;
public class widgetProviderMarshaler implements JmsProviderMarshaler
{
private SourceTransformer transformer = new SourceTransformer();
public Message createMessage(MessageExchange exchange, NormalizedMessage in, Session session) throws Exception
{
TextMessage text = session.createTextMessage();
text.setText(transformer.contentToString(in));
return text;
}
public void populateMessage(Message message, MessageExchange exchange, NormalizedMessage normalizedMessage) throws Exception
{
TextMessage textMessage = (TextMessage) message;
Source source = new StringSource(textMessage.getText());
normalizedMessage.setContent(source);
}
}Configuring the provider
You configure a provider to use a custom marshaler using its
marshaler attribute. The marshaler attribute's value is a reference to a bean element specifying the class of your custom marshaler implementation.
Example 6.6, “Configuring a Provider to Use a Customer Marshaler” shows configuration for a provider that uses a custom marshaler.
Example 6.6. Configuring a Provider to Use a Customer Marshaler
<beans xmlns:jms="http://servicemix.apache.org/jms/1.0"
... >
...
<jms:soap-provider wsdl="classpath:widgets.wsdl"
destinationName="widgetQueue"
connectionFactory="#connectionFactory"
marshaler="#myProviderMarshaler" />
<bean id="myProviderMarshaler" class="com.widgetVendor.example.widgetProviderMarshaler" />
...
</beans>Note
You can also configure a provider to use a custom marshaler by adding a child
marshaler element to the provider's configuration. The marshaler element simply wraps the bean element that configures the marshaler.
