Introducing Spring Framework

Chapter 11 ■ Integrating Your Spring Application with External Systems
import com.apress.isf.java.model.Document;
import com.apress.isf.java.utils.XmlUtils;
import com.apress.isf.spring.data.DocumentDAO;
@Component
public class JMSConsumer implements MessageListener{
}
@Autowired
DocumentDAO documentDAO;
@Override
public void onMessage(Message message) {
TextMessage textMessage = (TextMessage)message;
try{
Document document = XmlUtils.fromXML(textMessage.getText(), Document.class);
documentDAO.save(document);
}catch(JMSException ex){
ex.printStackTrace();
}
}
Let’s analyze what you are doing in Listing 11-2. First, you are implementing the javax.jms.MessageListener.
The JMS API exposes this interface where you need to implement the onMessage method; this method accepts a
javax.jms.Message that will contain the message. Also, you are using a small Utility class, which will help to convert
the XML into a document object and be saved into the database using the DocumentDAO implementation. Next, take a
look at Listing 11-3, which shows the Utility class that is used in the consumer.
Listing 11-3. XmlUtils.java
package com.apress.isf.java.utils;
import com.thoughtworks.xstream.XStream;
public class XmlUtils {
public static String toXML(T object){
XStream xstream = new XStream();
xstream.alias(object.getClass().getSimpleName().toLowerCase(), object.getClass());
return xstream.toXML(object);
}
}
@SuppressWarnings({ "unchecked"})
public static T fromXML(String xml, Class _class){
XStream xstream = new XStream();
xstream.alias(_class.getSimpleName().toLowerCase(), _class);
return (T)xstream.fromXML(xml);
}
151