如何使用EJB3.0

1. import javax.ejb.Stateless.*;

2. 
   

3. /**

4. * A simple stateless session bean implementing the incrementValue() method of the * CalculateEJB interface.

5. */

6. 
   

7. @Stateless(name="CalculateEJB")

8. public class CalculateEJBBean

9. implements CalculateEJB

10. {

11. int value = 0;

12. public String incrementValue()

13. {

14. value++;

15. return "value incremented by 1";

16. }

17. }

1. import javax.persistence.*;

2. import java.util.ArrayList;

3. import java.util.Collection;

4. 
   

5. @Entity

6. @Table(name = "EMPLOYEES")

7. public class Employee implements java.io.Serializable

8. {

9. private int empId;

10. private String eName;

11. private double sal;

12. 
    

13. @Id

14. @Column(name="EMPNO", primaryKey=true)

15. public int getEmpId()

16. {

17. return empId;

18. }

19. 
    

20. public void setEmpId(int empId)

21. {

22. this.empId = empId;

23. }

24. 
    

25. public String getEname()

26. {

27. return eName;

28. }

29. 
    

30. public void setEname(String eName)

31. {

32. this.eName = eName;

33. }

34. 
    

35. public double getSal()

36. {

37. return sal;

38. }

39. 
    

40. public void setSal(double sal)

41. {

42. this.sal = sal;

43. }

44. 
    

45. public String toString()

46. {

47. StringBuffer buf = new StringBuffer();

48. buf.append("Class:")

49. .append(this.getClass().getName()).append(" :: ").append(" empId:").append(getEmpId()).append(" ename:").append(getEname()).append("sal:").append(getSal());

50. return buf.toString();

51. }

52. }

1. import javax.ejb.MessageDriven;

2. import javax.ejb.ActivationConfigProperty;

3. import javax.ejb.Inject;

4. import javax.jms.*;

5. import java.util.*;

6. import javax.ejb.TimedObject;

7. import javax.ejb.Timer;

8. import javax.ejb.TimerService;

9. @MessageDriven(

10. activationConfig = {

11. @ActivationConfigProperty(propertyName="connectionFactoryJndiName", propertyValue="jms/TopicConnectionFactory"),

12. @ActivationConfigProperty(propertyName="destinationName", propertyValue="jms/myTopic"),

13. @ActivationConfigProperty(propertyName="destinationType", propertyValue="javax.jms.Topic"),

14. @ActivationConfigProperty(propertyName="messageSelector", propertyValue="RECIPIENT = 'MDB'")

15. }

16. )

17. 
    

18. /**

19. * A simple Message-Driven Bean that listens to the configured JMS Queue or Topic and gets notified

20. via an * invocation of it's onMessage() method when a message has been posted to the Queue or Topic. The bean

21. * prints the contents of the message.

22. */

23. 
    

24. public class MessageLogger implements MessageListener, TimedObject

25. {

26. 
    

27. @Inject javax.ejb.MessageDrivenContext mc;

28. 
    

29. public void onMessage(Message message)

30. {

31. System.out.println("onMessage() - " + message);

32. try

33. {

34. String subject = message.getStringProperty("subject");

35. String inmessage = message.getStringProperty("message");

36. System.out.println("Message received\n\tDate: " + new java.util.Date() + "\n\tSubject: " + subject + "\n\tMessage: " + inmessage + "\n");

37. System.out.println("Creating Timer a single event timer");

38. TimerService ts = mc.getTimerService();

39. Timer timer = ts.createTimer(30000, subject);

40. System.out.println("Timer created by MDB at: " + new Date(System.currentTimeMillis()) +" with info: "+subject);

41. }

42. catch (Throwable ex)

43. {

44. ex.printStackTrace();

45. }

46. }

47. 
    

48. public void ejbTimeout(Timer timer)

49. {

50. System.out.println("EJB 3.0: Timer with MDB");

51. System.out.println("ejbTimeout() called at: " + new Date(System.currentTimeMillis()));

52. return;

53. }

54. }

import javax.naming.Context;  import javax.naming.InitialContext;   /**  * A simple bean client which calls methods on a stateless session bean.  */   public class CalculateejbClient  {  public static void main(String [] args)  {  Context context = new InitialContext();  CalculateEJB myejb =  (CalculateEJB)context.lookup("java:comp/env/ejb/CalculateEJB");  myejb.incrementValue();  }  }