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。