Writing Enterprise Applications with Java™ 2 SDK, Enterprise Edition phần 5 pdf

LESSON 3 COOPERATING ENTERPRISE BEANS

46 SEPTEMBER 27, 2000

Change the Session Bean

In this lesson and as shown in Figure 14, the entity bean is a client of the session bean. This

means the entity bean gets its data from the session bean instead of from BonusServlet as it

did in Lesson 2 A Simple Entity Bean (page 27). So, the calcBonus method in the session

bean is modified to take the social security number as a parameter and create the entity bean.

Figure 14 Beans Working Together

CalcHome

The CalcHome interface is unchanged. It has the same create method that returns an

instance of the remote interface.

package Beans;

import java.rmi.RemoteException;

import javax.ejb.CreateException;

import javax.ejb.EJBHome;

public interface CalcHome extends EJBHome {

public Calc create()

throws CreateException, RemoteException;

}

Session Bean

(Application Server)

calcBonus method

getRecord method

Database

HTML Form

Browser

bonus.html

Servlet

(Web Server)

BonusServlet.class

Entity Bean