有状态会话Bean实验指导.doc

开发EJB2.X的有状态会话Bean步骤1：新建名为CountBean的J2EE1.4工程。设置工程的源程序目录为src，目的目录output为bin。步骤2：在新建向导中，选择JBoss-IDE | EJB Components | Session Bean创建会话Bean。步骤3：设置Session Bean的各种参数，点击Finish 按钮，即可看到生成的EJB类框架代码。其中各参数解释如下：Source folder：源程序所在目录；Package：源程序的包名；Name：Session Bean类的类名；Superclass和Interfaces：取默认值即可；Select the type of the EJB：选择EJB的类型；Select the access of the EJB：选择EJB的接口类型，会话Bean通常是Remote接口；Which method stubs would you like to create? ：EJB类要实现的方法，应选择Inherited abstract methods 和ejbCreate( ) method生命周期方法。步骤4：在Package Explorer中，利用EJB类的右键菜单添加商务方法。步骤5：设置Business方法的参数。完整的CountBean.java代码如下：package count;import java.rmi.RemoteException;import javax.ejb.EJBException;import javax.ejb.SessionBean;import javax.ejb.SessionContext;import javax.ejb.CreateException;public class CountBean implements SessionBean public int val;public void setSessionContext(SessionContext ctx)throws EJBException,RemoteException / TODO Auto-generated method stub System.out.println(setSessionContext();public void ejbRemove() throws EJBException, RemoteException / TODO Auto-generated method stub System.out.println(ejbRemove();public void ejbActivate() throws EJBException, RemoteException / TODO Auto-generated method stub System.out.println(ejbActivate();public void ejbPassivate() throws EJBException, RemoteException / TODO Auto-generated method stub System.out.println(ejbPassivate);public void ejbCreate(int val) throws CreateException / TODO Auto-generated method stubthis.val=val;System.out.println(ejbCreate();public int count() / TODO Auto-generated method stubSystem.out.println(count();return +val;步骤6：分别建立对应于Remote接口和Home接口的java接口文件。Remote接口代码如下：package count;import javax.ejb.EJBObject;import java.rmi.RemoteException;public interface Count extends EJBObjectpublic int count() throws RemoteException;Home接口的代码如下：package count;import javax.ejb.EJBHome;import javax.ejb.CreateException;import java.rmi.RemoteException;public interface CountHome extends EJBHomepublic Count create(int val)throws CreateException,RemoteException;结构如下：步骤7：在工程下建立Count子目录，作为没有打包的EJB模块。在Count子目录下，再新建count目录。步骤8：把bin目录中自动编译生成的class文件导入到count子目录下。步骤9：在Count子目录下建立META-INF子目录，并建立ejb-jar.xml 和jboss.xml 配置文件。ejb-jar.xml代码如下：Countcount.CountHomecount.Countcount.CountBeanStatefulContainerjboss.xml代码如下： Count Count 步骤10：在项目CountBean下建立一个ant的XML文件packaging-build.xml。在packaging-build.xml的右键菜单上执行ant命令，打包生成jar文件。packaging-build.xml代码如下：压缩完成提示信息如下：目录结构如下图：步骤11：启动jboss服务器，显示界面如下：把打包生成的Count.jar文件拷贝到C:jboss-4.0.4.GAserverdefaultdeploy路径下（不同机器，安装路径不同），jboss服务器如果成功部署该Count组件，则显示如下所示信息：步骤12：在新建向导中，利用向导JBoss-IDE | EJB Test Client 建立EJB客户机程序。步骤13：设置EJB客户机的各种参数。客户机代码如下：package count;import junit.framework.TestCase;import java.util.Hashtable;import javax.rmi.PortableRemoteObject;import javax.naming.Context;import javax.naming.InitialContext;public class TestCount extends TestCase public TestCount() super();protected count.CountHome home;protected Context getInitialContext() throws Exception Hashtable props = new Hashtable();props.put(Context.INITIAL_CONTEXT_FACTORY,erfaces.NamingContextFactory);props.put(Context.URL_PKG_PREFIXES,org.jboss.naming:erfaces);props.put(Context.PROVIDER_URL, jnp:/localhost:1099);Context ctx = new InitialContext(props);return ctx;protected count.CountHome getHome() throws Exception Context ctx = this.getInitialContext();Object o = ctx.lookup(Count);count.CountHome intf = (count.CountHome) PortableRemoteObject.narrow(o,count.CountHome.class);return intf;protected void setUp() throws Exception this.home = this.getHome();public void testCount() try Count count=new Count5; int countVal=0; System.out.println(Instantiating Beans .); for(int i=0;i5;i+) counti=this.home.create(countVal); countVal=counti.count(); System.out.println(countVal); Thread.sleep(500); System.out.println(Calling count() on Beans .); for(int i=0;i5;i+) countVal=counti.count(); System.out.println(countVal); Thread.sleep(500); for(int i=0;i5;i+) counti.remove(); catch(Exception e) e.printStackTrace(); 步骤14：运行客户机程序TestCount.java。出现错误信息是因为设置Contex的类没有找到。因为根据JBoss文档，Client目录的类库是专门为运行客户机程序设立的。简单的解决办法就是添加JBoss的Client目录下的所有类库到工程的路径中。步骤15：在工程的右键