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参考文献：

myeclipse+jboss开发EJB3.0之实体Bean

MyEclipse+JBoss开发EJB3.0

ejb3.0中persistence.xml文件

EJB项目中Persistence.xml配置

 

一. 配置

       Jboss有一个默认的数据源DefaultDS，他使用Jboss内置的HSQLDB数据库。实际应用中你可能使用不同的数据库，如MySql、MsSqlServer、Oracle等。各种数据库的数据源配置模版你可以在[Jboss_home]\docs\examples\jca 目录中找到，默认名称为：数据库名+ -ds.xml 。不管你使用那种数据库都需要把他的驱动类Jar 包放置在[Jboss_home]\server\all\lib 目录下，放置后需要启动Jboss服务器。前一篇博客有提到相关内容： JBoss中配置数据源出现错误：“Failed
to register driver for: com.mysql.jdbc.Driver”的解决方法  
        下面介绍Mysql的数据源配置，数据源配置文件的取名格式必须为 xxx–ds.xml ,如:mysql-ds.xml ，mssqlserver-ds.xml，oracle-ds.xml 。 数据源文件配置好后需要放置在[jboss_home]/server/config-name/deploy目录下,我现在采用的配置名为：default,所以路径为[jboss_home]/server/default/deploy目录下面定义一个名为MySqlDS的Mysql数据源，连接数据库为ejb，数据库登录用户名为root，密码为root，数据库驱动类为com.mysql.jdbc.Driver。大家只需修改数据库名及登录用户名密码就可以直接使用。
mysql-ds.xml

 

 

<?xml version="1.0" encoding="UTF-8"?></p> <p><!-- $Id: mysql-ds.xml 41017 2006-02-07 14:26:14Z acoliver $ --><br /> <!-- Datasource config for MySQL using 3.0.9 available from:</p> <p>http://www.mysql.com/downloads/api-jdbc-stable.html</p> <p>--></p> <p><datasources><br /> <local-tx-datasource><br /> <jndi-name>MySqlDS</jndi-name><br /> <connection-url>jdbc:mysql://localhost:3306/ejb?useUnicode=true&characterEncoding=UTF-8</connection-url><br /> <driver-class>com.mysql.jdbc.Driver</driver-class><br /> <user-name>root</user-name><br /> <password>root</password><br /> <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter</exception-sorter-class-name><br /> <!-- should only be used on drivers after 3.22.1 with "ping" support<br /> <valid-connection-checker-class-name>org.jboss.resource.adapter.jdbc.vendor.MySQLValidConnectionChecker</valid-connection-checker-class-name><br /> --><br /> <!-- sql to call when connection is created<br /> <new-connection-sql>some arbitrary sql</new-connection-sql><br /> --><br /> <!-- sql to call on an existing pooled connection when it is obtained from pool - MySQLValidConnectionChecker is preferred for newer drivers<br /> <check-valid-connection-sql>some arbitrary sql</check-valid-connection-sql><br /> --></p> <p> <!-- corresponding type-mapping in the standardjbosscmp-jdbc.xml (optional) --><br /> <metadata><br /> <type-mapping>mySQL</type-mapping><br /> </metadata><br /> </local-tx-datasource><br /> </datasources>

二. 开发实体bean

开发前先介绍需要映射的数据库表：person

 

注意：在这里并没有在数据库中建表，表是在发布ejb这个jar包的时候创建的。
Person.java

 

package edu.sjtu.erp.ejbstudy.bean;</p> <p>import java.io.Serializable;<br /> import java.util.Date;</p> <p>import javax.persistence.Column;<br /> import javax.persistence.Entity;<br /> import javax.persistence.GeneratedValue;<br /> import javax.persistence.GenerationType;<br /> import javax.persistence.Id;<br /> import javax.persistence.Table;<br /> import javax.persistence.Temporal;<br /> import javax.persistence.TemporalType;</p> <p>@SuppressWarnings("serial")<br /> @Entity<br /> @Table(name = "Person")<br /> public class Person implements Serializable {</p> <p> private Integer personid;<br /> private String name;<br /> private boolean sex;<br /> private Short age;<br /> private Date birthday;</p> <p> @Id<br /> @GeneratedValue(strategy=GenerationType.AUTO)<br /> public Integer getPersonid() {<br /> return personid;<br /> }<br /> public void setPersonid(Integer personid) {<br /> this.personid = personid;<br /> }</p> <p> @Column(nullable=false,length=32)<br /> public String getName() {<br /> return name;<br /> }<br /> public void setName(String name) {<br /> this.name = name;<br /> }</p> <p> @Column(nullable=false)<br /> public boolean getSex() {<br /> return sex;<br /> }<br /> public void setSex(boolean sex) {<br /> this.sex = sex;<br /> }</p> <p> @Column(nullable=false)<br /> public Short getAge() {<br /> return age;<br /> }<br /> public void setAge(Short age) {<br /> this.age = age;<br /> }</p> <p> @Temporal(value=TemporalType.DATE)<br /> public Date getBirthday() {<br /> return birthday;<br /> }<br /> public void setBirthday(Date birthday) {<br /> this.birthday = birthday;<br /> }</p> <p>}<br />

 

为了使用上面的实体Bean,我们定义一个Session Bean作为他的使用者。下面是Session Bean 的业务接，他定义了两个业务方法insertPerson和getPersonNameByID，insertPerson用作添加一个Person，getPersonNameByID 根据personid获取人员的姓名。

PersonDAO.java

 

package edu.sjtu.erp.ejbstudy.dao;</p> <p>import java.util.Date;</p> <p>public interface PersonDAO {<br /> public boolean insertPerson(String name,boolean sex,Short age,Date birthday);<br /> public String getPersonNameById(int personid);</p> <p>}<br /> 下面是Session Bean的实现 

 

 

package edu.sjtu.erp.ejbstudy.impl;<br /> import java.util.Date;<br /> import java.util.List;</p> <p>import javax.ejb.Remote;<br /> import javax.ejb.Stateless;<br /> import javax.persistence.EntityManager;<br /> import javax.persistence.PersistenceContext;<br /> import javax.persistence.Query;</p> <p>import edu.sjtu.erp.ejbstudy.bean.Person;<br /> import edu.sjtu.erp.ejbstudy.dao.PersonDAO;</p> <p>@Stateless<br /> @Remote(PersonDAO.class)<br /> public class PersonDAOBean implements PersonDAO {</p> <p> @PersistenceContext<br /> protected EntityManager em;</p> <p> @Override<br /> public boolean insertPerson(String name, boolean sex, Short age,<br /> Date birthday) {<br /> try{<br /> Person person=new Person();<br /> person.setName(name);<br /> person.setSex(sex);<br /> person.setAge(age);<br /> person.setBirthday(birthday);<br /> em.persist(person);</p> <p> }catch(Exception e){<br /> e.printStackTrace();<br /> return false;<br /> }<br /> // TODO Auto-generated method stub<br /> return true;<br /> }</p> <p> @Override<br /> public String getPersonNameById(int personid) {<br /> // TODO Auto-generated method stub<br /> Person person=em.find(Person.class, Integer.valueOf(personid));<br /> return person.getName();<br /> }</p> <p> public Person getPersonByID(int personid) {<br /> return em.find(Person.class, personid);<br /> } </p> <p> public boolean updatePerson(Person person) {<br /> try {<br /> em.merge(person);//更新数据用merge<br /> } catch (Exception e) {<br /> e.printStackTrace();<br /> return false;<br /> }<br /> return true;<br /> } </p> <p> public List getPersonList() {<br /> Query query = em.createQuery("from Person order by personid asc");<br /> List list = query.getResultList();<br /> return list;<br /> } </p> <p>}<br />         上面我们使用到了一个对象：EntityManager em，EntityManager 是由EJB容器自动地管理和配置的，不需要用户自己创建，他用作操作实体Bean。关于他的更多介绍请参考持久化实体管理器EntityManager。 上面em.find()方法用作查询主键ID 为personid的记录。em.persist()方法用作向数据库插入一条记录。
大家可能感觉奇怪，在类中并没有看到对EntityManager em进行赋值，后面却可以直接使用他。这是因为在实体Bean加载时，容器通过@PersistenceContext注释动态注入EntityManager 对象。
        如果persistence.xml文件中配置了多个不同的持久化内容。你需要指定持久化名称注入EntityManager 对象，可以通过@PersistenceContext注释的unitName属性进行指定，例：

 

 

@PersistenceContext(unitName="ejb")<br /> EntityManager em; 如果只有一个持久化内容配置，不需要明确指定。 

 

下面是persistence.xml文件的配置:

<?xml version="1.0" encoding="UTF-8" ?><br /> <persistence xmlns="http://java.sun.com/xml/ns/persistence"<br /> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"<br /> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence<br /> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0"><br /> <persistence-unit name="ejb"><br /> <jta-data-source>java:/MySqlDS</jta-data-source><br /> <properties><br /> <property name="hibernate.hbm2ddl.auto" value="create-drop"/><br /> <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" /><br /> <property name="hibernate.show_sql" value="true" /><br /> </properties><br /> </persistence-unit><br /> </persistence>

三.打包项目并发布

 

1. 配置数据源文件mysql-ds.xml并放置在[jboss_home]/server/deploy/deploy 目录，把数据库驱动Jar 包mysql-connector-java-bin.jar放置在[Jboss_home]\server\default\lib 目录下，放置后需要重启Jboss服务器。如果数据源已经存在就不需要配置。
2. 配置persistence.xml文件，在文件中指定使用的源据源及各项参数。
3. 把实体类和persistence.xml文件打成Jar，persistence.xml 放在jar 文件的META-INF目录
打包方法：在eclipse中右键项目EJBStudy->export->java->jar file，然后选择要打包的内容，如下图所示：

将生成的EJBStudy.jar放到目录jboss-5.0.1.GA\server\default\deploy下。这个时候eclipse的console中会提示信息：

 

13:51:33,390 INFO [Ejb3DependenciesDeployer] Encountered deployment AbstractVFSDeploymentContext@1458635375{vfszip:/D:/Program%20Files%20(x86)/JavaEE/jboss-5.0.1.GA/server/default/deploy/EJBStudy.jar/}<br /> 13:51:33,391 INFO [Ejb3DependenciesDeployer] Encountered deployment AbstractVFSDeploymentContext@1458635375{vfszip:/D:/Program%20Files%20(x86)/JavaEE/jboss-5.0.1.GA/server/default/deploy/EJBStudy.jar/}<br /> 13:51:33,417 INFO [JBossASKernel] Created KernelDeployment for: EJBStudy.jar<br /> 13:51:33,417 INFO [JBossASKernel] installing bean: jboss.j2ee:jar=EJBStudy.jar,name=PersonDAOBean,service=EJB3<br /> 13:51:33,417 INFO [JBossASKernel] with dependencies:<br /> 13:51:33,417 INFO [JBossASKernel] and demands:<br /> 13:51:33,417 INFO [JBossASKernel] jboss.ejb:service=EJBTimerService<br /> 13:51:33,417 INFO [JBossASKernel] persistence.unit:unitName=#ejb<br /> 13:51:33,417 INFO [JBossASKernel] and supplies:<br /> 13:51:33,418 INFO [JBossASKernel] jndi:PersonDAOBean/remote-edu.sjtu.erp.ejbstudy.dao.PersonDAO<br /> 13:51:33,418 INFO [JBossASKernel] Class:edu.sjtu.erp.ejbstudy.dao.PersonDAO<br /> 13:51:33,418 INFO [JBossASKernel] jndi:PersonDAOBean/remote<br /> 13:51:33,418 INFO [JBossASKernel] Added bean(jboss.j2ee:jar=EJBStudy.jar,name=PersonDAOBean,service=EJB3) to KernelDeployment of: EJBStudy.jar<br /> 13:51:33,426 INFO [PersistenceUnitDeployment] Starting persistence unit persistence.unit:unitName=#ejb<br /> 13:51:33,428 WARN [Ejb3Configuration] Persistence provider caller does not implement the EJB3 spec correctly. PersistenceUnitInfo.getNewTempClassLoader() is null.<br /> 13:51:33,429 INFO [AnnotationBinder] Binding entity from annotated class: edu.sjtu.erp.ejbstudy.bean.Person<br /> 13:51:33,429 INFO [EntityBinder] Bind entity edu.sjtu.erp.ejbstudy.bean.Person on table Person<br /> 13:51:33,437 INFO [HibernateSearchEventListenerRegister] Unable to find org.hibernate.search.event.FullTextIndexEventListener on the classpath. Hibernate Search is not enabled.<br /> 13:51:33,438 INFO [ConnectionProviderFactory] Initializing connection provider: org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider<br /> 13:51:33,438 INFO [InjectedDataSourceConnectionProvider] Using provided datasource<br /> 13:51:33,438 INFO [SettingsFactory] RDBMS: MySQL, version: 5.5.16<br /> 13:51:33,438 INFO [SettingsFactory] JDBC driver: MySQL-AB JDBC Driver, version: mysql-connector-java-5.1.18 ( Revision: tonci.grgin@oracle.com-20110930151701-jfj14ddfq48ifkfq )<br /> 13:51:33,439 INFO [Dialect] Using dialect: org.hibernate.dialect.MySQLDialect<br /> 13:51:33,439 INFO [TransactionFactoryFactory] Transaction strategy: org.hibernate.ejb.transaction.JoinableCMTTransactionFactory<br /> 13:51:33,439 INFO [TransactionManagerLookupFactory] instantiating TransactionManagerLookup: org.hibernate.transaction.JBossTransactionManagerLookup<br /> 13:51:33,439 INFO [TransactionManagerLookupFactory] instantiated TransactionManagerLookup<br /> 13:51:33,439 INFO [SettingsFactory] Automatic flush during beforeCompletion(): disabled<br /> 13:51:33,439 INFO [SettingsFactory] Automatic session close at end of transaction: disabled<br /> 13:51:33,439 INFO [SettingsFactory] JDBC batch size: 15<br /> 13:51:33,439 INFO [SettingsFactory] JDBC batch updates for versioned data: disabled<br /> 13:51:33,439 INFO [SettingsFactory] Scrollable result sets: enabled<br /> 13:51:33,439 INFO [SettingsFactory] JDBC3 getGeneratedKeys(): enabled<br /> 13:51:33,439 INFO [SettingsFactory] Connection release mode: auto<br /> 13:51:33,439 INFO [SettingsFactory] Maximum outer join fetch depth: 2<br /> 13:51:33,439 INFO [SettingsFactory] Default batch fetch size: 1<br /> 13:51:33,439 INFO [SettingsFactory] Generate SQL with comments: disabled<br /> 13:51:33,439 INFO [SettingsFactory] Order SQL updates by primary key: disabled<br /> 13:51:33,440 INFO [SettingsFactory] Order SQL inserts for batching: disabled<br /> 13:51:33,440 INFO [SettingsFactory] Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory<br /> 13:51:33,440 INFO [ASTQueryTranslatorFactory] Using ASTQueryTranslatorFactory<br /> 13:51:33,440 INFO [SettingsFactory] Query language substitutions: {}<br /> 13:51:33,440 INFO [SettingsFactory] JPA-QL strict compliance: enabled<br /> 13:51:33,440 INFO [SettingsFactory] Second-level cache: enabled<br /> 13:51:33,440 INFO [SettingsFactory] Query cache: disabled<br /> 13:51:33,440 INFO [SettingsFactory] Cache region factory : org.hibernate.cache.impl.bridge.RegionFactoryCacheProviderBridge<br /> 13:51:33,440 INFO [RegionFactoryCacheProviderBridge] Cache provider: org.hibernate.cache.HashtableCacheProvider<br /> 13:51:33,440 INFO [SettingsFactory] Optimize cache for minimal puts: disabled<br /> 13:51:33,440 INFO [SettingsFactory] Cache region prefix: persistence.unit:unitName=#ejb<br /> 13:51:33,440 INFO [SettingsFactory] Structured second-level cache entries: disabled<br /> 13:51:33,440 INFO [SettingsFactory] Echoing all SQL to stdout<br /> 13:51:33,440 INFO [SettingsFactory] Statistics: disabled<br /> 13:51:33,440 INFO [SettingsFactory] Deleted entity synthetic identifier rollback: disabled<br /> 13:51:33,440 INFO [SettingsFactory] Default entity-mode: pojo<br /> 13:51:33,440 INFO [SettingsFactory] Named query checking : enabled<br /> 13:51:33,443 INFO [SessionFactoryImpl] building session factory<br /> 13:51:33,447 INFO [SessionFactoryObjectFactory] Factory name: persistence.unit:unitName=#ejb<br /> 13:51:33,447 INFO [NamingHelper] JNDI InitialContext properties:{java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory, java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces}<br /> 13:51:33,457 INFO [SessionFactoryObjectFactory] Bound factory to JNDI name: persistence.unit:unitName=#ejb<br /> 13:51:33,457 WARN [SessionFactoryObjectFactory] InitialContext did not implement EventContext<br /> 13:51:33,459 INFO [SchemaExport] Running hbm2ddl schema export<br /> 13:51:33,459 INFO [SchemaExport] exporting generated schema to database<br /> 13:51:33,532 INFO [SchemaExport] schema export complete<br /> 13:51:33,534 INFO [NamingHelper] JNDI InitialContext properties:{java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory, java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces}<br /> 13:51:33,550 INFO [SessionSpecContainer] Starting jboss.j2ee:jar=EJBStudy.jar,name=PersonDAOBean,service=EJB3<br /> 13:51:33,551 INFO [EJBContainer] STARTED EJB: edu.sjtu.erp.ejbstudy.impl.PersonDAOBean ejbName: PersonDAOBean<br /> 13:51:33,558 INFO [JndiSessionRegistrarBase] Binding the following Entries in Global JNDI:</p> <p> PersonDAOBean/remote - EJB3.x Default Remote Business Interface<br /> PersonDAOBean/remote-edu.sjtu.erp.ejbstudy.dao.PersonDAO - EJB3.x Remote Business Interface<br /> 我们在mysql数据库中也会看到ejb数据中创建了一张person表。

四.测试

创建一个EJB客户端来测试，代码如下

package edu.sjtu.erplab.ejb.test;</p> <p>import java.text.ParseException;<br /> import java.text.SimpleDateFormat;<br /> import java.util.Properties;</p> <p>import javax.naming.InitialContext;<br /> import javax.naming.NamingException;</p> <p>import edu.sjtu.erp.ejbstudy.dao.PersonDAO;</p> <p>public class EJBClient {</p> <p> /**<br /> * @param args<br /> * @throws ParseException<br /> */<br /> public static void main(String[] args) throws ParseException {<br /> // TODO Auto-generated method stub<br /> Properties props=new Properties();<br /> //坑爹的写成：org.jnp.interface.NamingContextFactory<br /> props.setProperty("java.naming.factory.initial", "org.jnp.interfaces.NamingContextFactory");<br /> props.setProperty("java.naming.provider.url", "localhost:1099");<br /> props.setProperty("java.naming.factory.url.pkgs", "org.jboss.naming");<br /> try<br /> {<br /> InitialContext ctx=new InitialContext(props);<br /> //InitialContext ctx=new InitialContext();</p> <p> PersonDAO persondao = (PersonDAO) ctx.lookup("PersonDAOBean/remote");<br /> SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");<br /> persondao.insertPerson("xuwei", true, (short)22,formatter.parse("1985-10-17"));//添加一个人<br /> System.out.println(persondao.getPersonNameById(1)); //取personid为1的人 </p> <p> }catch(NamingException e){<br /> System.out.println(e.getMessage());<br /> }<br /> }</p> <p>}<br /> 不明白为什么会有如下这么多警告，不过数据已经正确插入表person中

13:54:55,200 WARN [InterceptorsFactory] EJBTHREE-1246: Do not use InterceptorsFactory with a ManagedObjectAdvisor, InterceptorRegistry should be used via the bean container<br /> 13:54:55,200 WARN [InterceptorsFactory] EJBTHREE-1246: Do not use InterceptorsFactory with a ManagedObjectAdvisor, InterceptorRegistry should be used via the bean container<br /> 13:54:55,200 WARN [InterceptorRegistry] applicable interceptors is non-existent for public edu.sjtu.erp.ejbstudy.bean.Person edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.getPersonByID(int)<br /> 13:54:55,203 WARN [InterceptorRegistry] applicable interceptors is non-existent for public boolean edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.insertPerson(java.lang.String,boolean,java.lang.Short,java.util.Date)<br /> 13:54:55,205 WARN [InterceptorRegistry] applicable interceptors is non-existent for public boolean edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.updatePerson(edu.sjtu.erp.ejbstudy.bean.Person)<br /> 13:54:55,208 WARN [InterceptorRegistry] applicable interceptors is non-existent for public java.lang.String edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.getPersonNameById(int)<br /> 13:54:55,210 WARN [InterceptorRegistry] applicable interceptors is non-existent for public java.util.List edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.getPersonList()<br /> 13:54:55,213 WARN [InterceptorRegistry] applicable interceptors is non-existent for public edu.sjtu.erp.ejbstudy.bean.Person edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.getPersonByID(int)<br /> 13:54:55,216 WARN [InterceptorRegistry] applicable interceptors is non-existent for public boolean edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.insertPerson(java.lang.String,boolean,java.lang.Short,java.util.Date)<br /> 13:54:55,218 WARN [InterceptorRegistry] applicable interceptors is non-existent for public boolean edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.updatePerson(edu.sjtu.erp.ejbstudy.bean.Person)<br /> 13:54:55,221 WARN [InterceptorRegistry] applicable interceptors is non-existent for public java.lang.String edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.getPersonNameById(int)<br /> 13:54:55,223 WARN [InterceptorRegistry] applicable interceptors is non-existent for public java.util.List edu.sjtu.erp.ejbstudy.impl.PersonDAOBean.getPersonList()<br /> 13:54:55,227 INFO [STDOUT] Hibernate: insert into Person (age, birthday, name, sex) values (?, ?, ?, ?)<br /> 13:54:55,301 INFO [STDOUT] Hibernate: select person0_.personid as personid72_0_, person0_.age as age72_0_, person0_.birthday as birthday72_0_, person0_.name as name72_0_, person0_.sex as sex72_0_ from Person person0_ where person0_.personid=?<br />