How do you invoke a Runnable using Spring Framework? - multithreading

Question

I have a service that needs to invoke a runnable class.
Here are the lines of code that are being used in my service.
#Autowired
private LinkBrc2MemberProfile brcTask;
// Background Task.
SimpleAsyncTaskExecutor sate = new SimpleAsyncTaskExecutor();
sate.createThread(new LinkBrc2MemberProfile(user));
Here is my Runnable class
#Service
public class LinkBrc2MemberProfile implements Runnable {
private final Logger log = LoggerFactory.getLogger(LinkBrc2MemberProfile.class);
#Autowired
private LoyaltyDao dao;
private Member member;
public LinkBrc2MemberProfile() {
super();
}
public LinkBrc2MemberProfile(Member member) {
this.member = member;
}
public void run() {
log.debug("*** Member User Name: " + member.getString("USER_NAME"));
String emailAddress = member.getString("USER_NAME");
Map<String, Object> map = dao.findBrcByEmailAddress( emailAddress );
log.debug("==========================================================");
if( ! map.isEmpty() ) {
try {
//a.CUSTOMER_ID, a.EMAIL_ADDRESS, b.card_no
String customerId = (String) map.get("CUSTOMER_ID");
String brcCardNumber = (String) map.get("CARD_NO");
log.debug("\ncustomerId: " + customerId + " brcCardNumber: " + brcCardNumber);
if(!brcCardNumber.equals("")) {
// Add the Be Rewarded Card.
HashMap<String, String> userAttributes = new HashMap<String, String>();
String brcNumber = member.getString("BREWARDED_CARD_NO");
if (brcNumber.equals("")) {
userAttributes.put("BREWARDED_CARD_NO", brcCardNumber);
try {
member.putAll(userAttributes);
} catch (Exception e) {
String errorMessage = "Unable to save user's BRC information due to: " + e.getMessage();
log.error("{}", errorMessage);
}
}
}
} catch (Exception e) {
log.error(e.getMessage());
e.printStackTrace();
}
}
}
I'm not seeing any errors in the log but at the same time it does not appear to be invoking the Runnable class. Am I missing an annotation somewhere? Are there any good examples that you can point me to, the only ones I have found use XML files to configure the runnable class I would like to use annotations. Thanks in Advance.
I've updated my service to do the following.
Please help, my DAO is NULL so it looks like my #Autowired in my Runnable class is not wiring it in.
I've added the following bean to my bean-config.xml file.
<bean id="brcType" class="com.ws.ocp.service.LinkBrc2MemberProfile" scope="prototype"/>
I removed my #Autowired annotation and added the following to my service class.
ClassPathResource rsrc = new ClassPathResource("bean-config.xml");
XmlBeanFactory factory = new XmlBeanFactory(rsrc);
LinkBrc2MemberProfile brcTask = (LinkBrc2MemberProfile) factory.getBean("brcType");
SimpleAsyncTaskExecutor sate = new SimpleAsyncTaskExecutor();
// Set Member attribute
brcTask.setMember(user);
// Executer
sate.execute(brcTask);
Why is my dao still null?

Answer 1

The runnable will throw a NullPointerException, since you create it yourself (using the new operator), instead of letting Spring create it. This obviously means that the autowired DAO attribute won't be autowired, which will lead to a NPE when calling dao.findBrcByEmailAddress(...).
You should get your Runnable instance from the bean factory (as a prototype), set its member attribute, and then submit it to the executor.

Answer 2

To answer your question of how to properly use a Prototype-Bean, this is my favorite way:
#Component
abstract class MyBean {
/* Factory method that will be installed by Spring */
#Lookup
protected abstract YourPrototypeBean createBean();
void someCode() {
YourPrototypeBean bean = createBean();
}
}
Since it's a factory method, you can create as many instances as you like.