EJB创建应用程序
要创建一个简单的EJB模块,我们将使用NetBeans“新建项目”向导。在下面的例子中,我们将创建一个名为Component的EJB模块项目。
创建项目
在NetBeans IDE中,选择文件>新建项目>(File > New Project >)。你会看到以下画面。
在项目类别中选择项目类型,Java EE中 ,项目类型为EJB模块 。单击下一步>(Next >)按钮。你会看到以下画面。
输入项目名称和位置。单击下一步>(Next >)按钮。你会看到以下画面。
选择下图中选项作为JBoss应用服务器 。单击Finish按钮。你会看到NetBeans中创建以下项目。
创建示例EJB
要创建一个简单的EJB,我们将使用NetBeans“新建”向导。在下面的例子中,我们将创建EjbComponent项目名为librarySessionBean的一个无状态的EJB类。
选择项目EjbComponent在项目资源管理器窗口,并在其上单击右键。选择New > Session Bean
,即可看到新的Bean向导会话。
输入会话bean名称和包名称。单击Finish按钮。你会看到NetBeans中创建以下EJB类。
LibrarySessionBean -无状态会话bean
LibrarySessionBeanLocal -本地接口的会话bean
我改变本地接口的远程接口,我们要访问我们的EJB在控制台基础的应用。远程/本地接口用于公开,一个EJB必须实现业务方法。
LibrarySessionBeanLocal被重命名为LibrarySessionBeanRemote和LibrarySessionBean实现LibrarySessionBeanRemote接口。
LibrarySessionBeanRemote
package com.tutorialspoint.stateless; import java.util.List; import javax.ejb.Remote; @Remote public interface LibrarySessionBeanRemote { void addBook(String bookName); List getBooks(); }
LibrarySessionBean
package com.tutorialspoint.stateless; import java.util.ArrayList; import java.util.List; import javax.ejb.Stateless; @Stateless public class LibrarySessionBean implements LibrarySessionBeanRemote { List<String> bookShelf; public LibrarySessionBean(){ bookShelf = new ArrayList<String>(); } public void addBook(String bookName) { bookShelf.add(bookName); } public List<String> getBooks() { return bookShelf; } }
建设项目
在项目资源管理器窗口中选择Ejb组件(Component)项目
右键点击它,打开上下文菜单。
选择清理并生成。
你会看到在NetBeans控制台输出以下输出。
ant -f C:EJBEjbComponent clean dist init: undeploy-clean: deps-clean: Deleting directory C:EJBEjbComponentuild Deleting directory C:EJBEjbComponentdist clean: init: deps-jar: Created dir: C:EJBEjbComponentuildclasses Copying 3 files to C:EJBEjbComponentuildclassesMETA-INF Created dir: C:EJBEjbComponentuildempty Created dir: C:EJBEjbComponentuildgenerated-sourcesap-source-output Compiling 2 source files to C:EJBEjbComponentuildclasses warning: [options] bootstrap class path not set in conjunction with -source 1.6 Note: C:EJBEjbComponentsrcjavacom utorialspointstateless LibraryPersistentBean.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 1 warning compile: library-inclusion-in-archive: Created dir: C:EJBEjbComponentdist Building jar: C:EJBEjbComponentdistEjbComponent.jar dist: BUILD SUCCESSFUL (total time: 3 seconds)
启动应用服务器
在服务窗口服务器下选择JBoss应用服务器
右键点击它,打开上下文菜单。
选择启动。
你会看到在NetBeans下JBoss应用服务器下面的输出,输出。
Calling C:jboss-5.1.0.GAin un.conf.bat ========================================================================= JBoss Bootstrap Environment JBOSS_HOME: C:jboss-5.1.0.GA JAVA: C:Program Files (x86)Javajdk1.6.0_21injava JAVA_OPTS: -Dprogram.name=run.bat -Xms128m -Xmx512m -server CLASSPATH: C:jboss-5.1.0.GAin un.jar ========================================================================= 16:25:50,062 INFO [ServerImpl] Starting JBoss (Microcontainer)... 16:25:50,062 INFO [ServerImpl] Release ID: JBoss [The Oracle] 5.1.0.GA (build: SVNTag=JBoss_5_1_0_GA date=200905221634) ... 16:26:40,420 INFO [TomcatDeployment] deploy, ctxPath=/admin-console 16:26:40,485 INFO [config] Initializing Mojarra (1.2_12-b01-FCS) for context '/admin-console' 16:26:42,362 INFO [TomcatDeployment] deploy, ctxPath=/ 16:26:42,406 INFO [TomcatDeployment] deploy, ctxPath=/jmx-console 16:26:42,471 INFO [Http11Protocol] Starting Coyote HTTP/1.1 on http-127.0.0.1-8080 16:26:42,487 INFO [AjpProtocol] Starting Coyote AJP/1.3 on ajp-127.0.0.1-8009 16:26:42,493 INFO [ServerImpl] JBoss (Microcontainer) [5.1.0.GA (build: SVNTag=JBoss_5_1_0_GA date=200905221634)] Started in 52s:427ms
部署项目
在项目资源管理器窗口中选择Ejb组件(Component)项目
右键点击它,打开上下文菜单。
选择部署。
你会看到在NetBeans控制台输出以下输出。
ant -f C:EJBEjbComponent -DforceRedeploy=true -Ddirectory.deployment.supported=false -Dnb.wait.for.caches=true run init: deps-jar: compile: library-inclusion-in-archive: Building jar: C:EJBEjbComponentdistEjbComponent.jar dist-directory-deploy: pre-run-deploy: Checking data source definitions for missing JDBC drivers... Distributing C:EJBEjbComponentdistEjbComponent.jar to [org.jboss.deployment.spi.LocalhostTarget@1e4f84ee] Deploying C:EJBEjbComponentdistEjbComponent.jar Applicaton Deployed Operation start started Operation start completed post-run-deploy: run-deploy: run: BUILD SUCCESSFUL (total time: 2 seconds)
JBoss应用服务器的日志输出
16:30:00,963 INFO [DeployHandler] Begin start, [EjbComponent.jar] ... 16:30:01,233 INFO [Ejb3DependenciesDeployer] Encountered deployment AbstractVFSDeploymentContext@12038795{vfszip:/C:/jboss-5.1.0.GA/server/default/deploy/EjbComponent.jar/} ... 16:30:01,281 INFO [JBossASKernel] jndi:LibrarySessionBean/remote-com.tutorialspoint.stateless.LibrarySessionBeanRemote 16:30:01,281 INFO [JBossASKernel] Class:com.tutorialspoint.stateless.LibrarySessionBeanRemote 16:30:01,281 INFO [JBossASKernel] jndi:LibrarySessionBean/remote 16:30:01,281 INFO [JBossASKernel] Added bean(jboss.j2ee:jar=EjbComponent.jar,name= LibrarySessionBean,service=EJB3) to KernelDeployment of: EjbComponent.jar 16:30:01,282 INFO [JBossASKernel] installing bean: jboss.j2ee:jar=EjbComponent.jar,name=BookMessageHandler,service=EJB3 16:30:01,282 INFO [JBossASKernel] with dependencies: 16:30:01,282 INFO [JBossASKernel] and demands: 16:30:01,282 INFO [JBossASKernel] jboss.ejb:service=EJBTimerService ... 16:30:01,283 INFO [EJB3EndpointDeployer] Deploy AbstractBeanMetaData@5497cb{name=jboss.j2ee:jar=EjbComponent.jar, name=LibrarySessionBean, service=EJB3_endpoint bean=org.jboss.ejb3.endpoint.deployers.impl.EndpointImpl properties=[container] constructor=null autowireCandidate=true} ... 16:30:01,394 INFO [SessionSpecContainer] Starting jboss.j2ee:jar=EjbComponent.jar,name=LibrarySessionBean,service=EJB3 16:30:01,395 INFO [EJBContainer] STARTED EJB: com.tutorialspoint.stateless.LibrarySessionBean ejbName: LibrarySessionBean 16:30:01,401 INFO [JndiSessionRegistrarBase] Binding the following Entries in Global JNDI: LibrarySessionBean/remote - EJB3.x Default Remote Business Interface LibrarySessionBean/remote-com.tutorialspoint.stateless.LibrarySessionBeanRemote - EJB3.x Remote Business Interface 16:30:02,723 INFO [SessionSpecContainer] Starting jboss.j2ee:jar=EjbComponent.jar,name=LibrarySessionBean,service=EJB3 16:30:02,723 INFO [EJBContainer] STARTED EJB: com.tutorialspoint.stateless.LibrarySessionBean ejbName: LibrarySessionBean 16:30:02,731 INFO [JndiSessionRegistrarBase] Binding the following Entries in Global JNDI: LibrarySessionBean/remote - EJB3.x Default Remote Business Interface LibrarySessionBean/remote-com.tutorialspoint.stateless.LibrarySessionBeanRemote - EJB3.x Remote Business Interface
创建客户端访问EJB
在NetBeans IDE中,选择文件>新建项目>(File > New Project >)。
在类别中选择项目类型,Java ,项目类型为Java应用程序 。单击下一步>(Next >)按钮。
输入项目名称和位置。单击Finish>按钮。我们选择的名称为EjbTester。
右键点击Project Explorer窗口中的项目名称。选择属性(properties) 。
在早先创建EJB组件项目中添加使用编译选项的添加项目按钮。
使用编译选项中添加JAR /文件夹按钮添加的JBoss库。 Jboss的库可以位于<JBoss安装文件夹>>客户端文件夹。
在EjbTester中创建文件名为jndi.properties的项目。
jndi.properties
java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces java.naming.provider.url=localhost
其下创建包com.tutorialspoint.test和EJBTester.java类。
EJBTester.java
package com.tutorialspoint.test; import com.tutorialspoint.stateless.LibrarySessionBeanRemote; import java.io.BufferedReader; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStreamReader; import java.util.List; import java.util.Properties; import javax.naming.InitialContext; import javax.naming.NamingException; public class EJBTester { BufferedReader brConsoleReader = null; Properties props; InitialContext ctx; { props = new Properties(); try { props.load(new FileInputStream("jndi.properties")); } catch (IOException ex) { ex.printStackTrace(); } try { ctx = new InitialContext(props); } catch (NamingException ex) { ex.printStackTrace(); } brConsoleReader = new BufferedReader(new InputStreamReader(System.in)); } public static void main(String[] args) { EJBTester ejbTester = new EJBTester(); ejbTester.testStatelessEjb(); } private void showGUI(){ System.out.println("**********************"); System.out.println("Welcome to Book Store"); System.out.println("**********************"); System.out.print("Options 1. Add Book 2. Exit Enter Choice: "); } private void testStatelessEjb(){ try { int choice = 1; LibrarySessionBeanRemote libraryBean = (LibrarySessionBeanRemote)ctx.lookup("LibrarySessionBean/remote"); while (choice != 2) { String bookName; showGUI(); String strChoice = brConsoleReader.readLine(); choice = Integer.parseInt(strChoice); if (choice == 1) { System.out.print("Enter book name: "); bookName = brConsoleReader.readLine(); libraryBean.addBook(bookName); }else if (choice == 2) { break; } } List<String> booksList = libraryBean.getBooks(); System.out.println("Book(s) entered so far: " + booksList.size()); for (int i = 0; i < booksList.size(); ++i) { System.out.println((i+1)+". " + booksList.get(i)); } LibrarySessionBeanRemote libraryBean1 = (LibrarySessionBeanRemote)ctx.lookup("LibrarySessionBean/remote"); List<String> booksList1 = libraryBean1.getBooks(); System.out.println( "***Using second lookup to get library stateless object***"); System.out.println( "Book(s) entered so far: " + booksList1.size()); for (int i = 0; i < booksList1.size(); ++i) { System.out.println((i+1)+". " + booksList1.get(i)); } } catch (Exception e) { System.out.println(e.getMessage()); e.printStackTrace(); }finally { try { if(brConsoleReader !=null){ brConsoleReader.close(); } } catch (IOException ex) { System.out.println(ex.getMessage()); } } } }
运行客户端访问EJB
在项目资源管理器中找到EJBTester.java。右键单击EJBTester类并选择运行文件 。
验证Netbeans控制台下面的输出。
run: ********************** Welcome to Book Store ********************** Options 1. Add Book 2. Exit Enter Choice: 1 Enter book name: Learn Java ********************** Welcome to Book Store ********************** Options 1. Add Book 2. Exit Enter Choice: 2 Book(s) entered so far: 1 1. Learn Java ***Using second lookup to get library stateless object*** Book(s) entered so far: 0 BUILD SUCCESSFUL (total time: 13 seconds)
在下面的章节中,我们将讨论这个完整的EJB应用程序的多个方面。
更多建议: