EJB 3.0 学习笔记—

EJB 3.0 学习笔记——Entity Bean（转）

在EJB 3.0 学习笔记——准备工作中只是简单的搭好了EJB3.0开发的基本环境，之

后就可以开发最简单的Session Bean了，我感兴趣的还是Entity Bean，所以接下来

我想先试验一下Entity Bean。

一、在JBoss中配置好Data Source
我使用的是MySQL数据库，所以首先将MySQL的JDBC驱动复制到
jboss-4.0.3SP1\server\all\lib目录，然后将jboss-4.0.3SP1\docs\examples\jca

下的mysql-ds.xml作出适当修改后复制到jboss-4.0.3SP1\server\all\deploy目录

下，这是我修改后的mysql-ds.xml文件：

<?xml version="1.0" encoding="UTF-8"?>

<datasources>
<local-tx-datasource>
    <jndi-name>MySqlDS</jndi-name>
    <connection-url>jdbc:mysql://localhost:3306/test</connection-url>
    <driver-class>com.mysql.jdbc.Driver</driver-class>
    <user-name>test</user-name>
    <password></password>
    <exception-sorter-class-

name>org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter</excepti

on-sorter-class-name>
    
    <!-- sql to call on an existing pooled connection when it is obtained

from pool
<check-valid-connection-sql>some arbitrary sql</check-valid-

connection-sql>
-->

<!-- corresponding type-mapping in the standardjbosscmp-jdbc.xml

(optional) -->
    <metadata>
       <type-mapping>mySQL</type-mapping>
    </metadata>
</local-tx-datasource>
</datasources>
这样之后，JBoss下的MySQL Data Source配置完成。

二、创建数据库并编写Entity Bean代码

create table book(
id int not null auto_increment primary key,
title varchar(20) not null,
author varchar(40) not null
);
新建Java Project，导入User Library：EJB3_JBoss，以下是类代码。

//Book.java
package ejb.bean.entity;

import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="book")
public class Book implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private Integer id;
private String title;
private String author;

public Book() {
  super();
}
public Book(Integer id, String title, String author) {
  super();
  this.id = id;
  this.title = title;
  this.author = author;
  }
@Override
public String toString() {

  return "Book: " + getId() + " Title " + getTitle() + "

Author " + getAuthor();
}
public String getAuthor() {
  return author;
}

@Id @GeneratedValue(strategy=GenerationType.AUTO)
public Integer getId() {
  return id;
}
public String getTitle() {
  return title;
}
public void setAuthor(String author) {
  this.author = author;
}
public void setId(Integer id) {
  this.id = id;
}
public void setTitle(String title) {
  this.title = title;
}

}

三、编写一个简单的Stateless Session Bean 并进行测试

//BookTestLocal.java
package ejb.bean.entity;

import javax.ejb.Local;

@Local
public interface BookTestLocal {

public void test();
}

//BookTestRemote.java
package ejb.bean.entity;

import javax.ejb.Remote;
@Remote
public interface BookTestRemote {

public void test();

}

//BookTestBean.java
package ejb.bean.entity;

import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

@Stateless
public class BookTestBean implements BookTestLocal, BookTestRemote {

@PersistenceContext
EntityManager em;
public void test() {
// TODO Auto-generated method stub
Book book = new Book(null, "My first bean book",

"Sebastian");
em.persist(book);

}

//Client.java
package ejb.client.entity;

import ejb.bean.entity.*;

import javax.naming.InitialContext;

/**
* Comment
*
* @author <a href="mailto:[email protected]">Bill Burke</a>
* @version $Revision: 1.1.6.7 $
*/
public class Client
{
   public static void main(String[] args) throws Exception
   {
      InitialContext ctx = new InitialContext();
      BookTestRemote book = (BookTestRemote) ctx.lookup

("BookTestBean/remote");

      book.test();

      System.out.println("test successful! ");

}
}

三、其他文件
将jboss-EJB-3.0_RC5-PFD\docs\tutorial中的找到的jndi.properties、log4j.xml

、builder.xml等复制到当前工程中，其中builder.xml需要修改。
//builder.xml
<?xml version="1.0"?>

<!--

=======================================================================

-->
<!-- JBoss build file

-->
<!--

=======================================================================

-->

   <property file="../local.properties" />
   <property environment="env"/>
   <property name="src.dir" value="${basedir}/src"/>
   <property name="jboss.home" value="E:/Programming/Servers/jboss-

4.0.3SP1/"/>
   <property name="jboss.server.config" value="all"/>
   <property name="build.dir" value="${basedir}/build"/>
   <property name="build.classes.dir" value="${build.dir}/classes"/>

<path id="classpath">
      
      <pathelement location="${basedir}"/>
      <fileset dir="${jboss.home}/lib">
         <include name="**/*.jar"/>
      </fileset>
      <fileset dir="${jboss.home}/server/${jboss.server.config}/lib">
         <include name="**/*.jar"/>
      </fileset>
      <fileset dir="${jboss.home}/server/

${jboss.server.config}/deploy/ejb3.deployer">
         <include name="*.jar"/>
      </fileset>
      <fileset dir="${jboss.home}/server/

${jboss.server.config}/deploy/jboss-aop-jdk50.deployer">
         <include name="*.jar"/>
      </fileset>
      <pathelement location="${build.classes.dir}"/>
   </path>

<!--

=================================================================== -->
<!-- Prepares the build directory

-->
<!--

=================================================================== -->
   <target name="prepare">
      <mkdir dir="${build.dir}"/>
      <mkdir dir="${build.classes.dir}"/>
   </target>

<!--

=================================================================== -->
<!-- Compiles the source code

-->
<!--

=================================================================== -->
   <target name="compile" depends="prepare">
      <javac srcdir="${src.dir}"
         destdir="${build.classes.dir}"
         debug="on"
         deprecation="on"
         optimize="off"
         includes="**">
         <classpath refid="classpath"/>
      </javac>
   </target>

   <target name="ejbjar" depends="compile">
      <jar jarfile="build/tutorial.jar">
         <fileset dir="${build.classes.dir}">
            <include name="**/*.class"/>
         </fileset>
      <fileset dir=".">
           <include name="META-INF/persistence.xml"/>
      </fileset>
      </jar>
      <copy file="build/tutorial.jar" todir="${jboss.home}/server/

${jboss.server.config}/deploy"/>
</target>

   <target name="run.stateless" depends="ejbjar">
      <java classname="ejb.client.stateless.Client" fork="yes" dir=".">
         <classpath refid="classpath"/>
      </java>
   </target>

<target name="run.stateful" depends="ejbjar">
       <java classname="ejb.client.stateful.Client" fork="yes"

dir=".">
          <classpath refid="classpath"/>
       </java>
</target>

<target name="run.timer" depends="ejbjar">
       <java classname="ejb.client.timer.Client" fork="yes"

dir=".">
          <classpath refid="classpath"/>
       </java>
</target>

<target name="run.entity" depends="ejbjar">
        <java classname="ejb.client.entity.Client"

fork="yes" dir=".">
           <classpath refid="classpath"/>
        </java>
  </target>

<!--

=================================================================== -->
<!-- Cleans up generated stuff

-->
<!--

=================================================================== -->
<target name="clean.db">
<delete dir="${jboss.home}/server/

${jboss.server.config}/data/hypersonic"/>
</target>

   <target name="clean">
      <delete dir="${build.dir}"/>
      <delete file="${jboss.home}/server/

${jboss.server.config}/deploy/tutorial.jar"/>
</target>

</project>

最后，在工程目录下新建目录META-INF，在目录META-INF新建persistence.xml文件

，以下是文件内容：
<?xml version="1.0" encoding="UTF-8"?>
<persistence>
   <persistence-unit name="test">
      <jta-data-source>java:/MySqlDS</jta-data-source>
      <properties>
      <property name="hibernate.dialect"

value="org.hibernate.dialect.MySQLDialect"/>
        <property name="hibernate.hbm2ddl.auto" value="update"/>
      </properties>
   </persistence-unit>
</persistence>

四、运行测试
run as->ant build后，选择运行目标为run.entity->run。
运行结果：
Buildfile: D:\Programs\Java\EclipseWork\EJB3\build.xml
prepare:
compile:
ejbjar:
run.entity:
[java] test successful!
BUILD SUCCESSFUL
Total time: 9 seconds

MySQL中select * from book;
id title author
1 My first bean book Sebastian
已经成功写入。

EJB 3.0 学习笔记——Entity Bean

EJB 3.0 学习笔记——Entity Bean（转）

你可能感兴趣的:(EJB 3.0 学习笔记——Entity Bean)