使用JBoss和PostgreSQL-----快速开发EJB和J2EE Web Application
Developing J2EE Web Application on Jboss and PostgreSQL(chinese version)
作者：Han QW, 转载请指明出处 如有不当之处，敬请指出
先安装JSDK，再安装JBoss.
安装JSDK,必须获得一套对应于用户的操作系统的JDK，
我的安装的文件目录是
WINDOWS2000: d:s1studio_jdkj2sdk1.4.1
linux： /root/s1studio_jdk/j2sdk1.4.1
为了用EJB, 需要一个j2ee-1.3.jar或者j2ee-1.2.jar,
如果安装了Sun One Studio 或者 J2EE （www.sun.com ）这个文件已经有.
把这个文件放在classpath路径上.
或者使用jboss-j2ee.jar, 安装JBoss后在$JBossclient中可找到.
建议安装Sun One Studio, 用Sun One Studio编译JAVA源程序,
不用设置classpath, 省去不少过程.
安装JBoss:
把JBoss的压缩包解开，放在任一目录上,
我的安装的文件目录是
/dose/jboss-3.0.4_tomcat-4.1.12 (REDHAT8.0)
E:jboss-3.0.4_tomcat-4.1.12 (WINDOWS2000)
WINDOWS2000, linux共用同一套JBoss.
配置JBoss：
启动JBoss需要执行一个脚本文件：
linux：run.sh
WINDOWS对应的是：run.bat
(1)
在JBossin
un.bat (for Windows)开头插入一行
set JAVA_HOME = d:s1studio_jdkj2sdk1.4.1
在JBossin
un.sh (for Linux)开头插入一行
JAVA_HOME="/root/s1studio_jdk/j2sdk1.4.1"
或者
(2)设置系统环境变量JAVA_HOME,指向JDK
运行JBoss, run.sh或者run.bat
当看到启动JBoss的信息时，说明启动了.
服务器简单的测试：
JBoss默认的WEB端口为8080，我们可以在打开一个浏览器输入地址
http://localhost:8080/jmx-console
当在浏览器看到JBoss的信息时，说明安装配置JBoss成功了.
建立下面的目录和文件(注意大小写).
FIRST.EAR
|
|-----META-INF (application.xml)
|
|-----First.jar
| |-----META-INF (ejb-jar.xml,jboss.xml)
| `-----Dev
| |-----First(FirstSession.java, FirstSessionHome.java, FirstSessionBean.java)
| |-----Delegate(NewDelegate.java)
| `-----Dao(MysqlDao.java)
|
`-----First.war(index.jsp)
|
`-----WEB-INF (jboss-web.xml, web.xml)
|-----classes
`-----lib
/*
**
**MysqlDao.java
**
*/
package
Dev.Dao;import java.sql.Connection;import java.sql.SQLException;import
java.sql.Statement;import java.sql.ResultSet;import
javax.naming.InitialContext;import javax.sql.DataSource;public class
MysqlDao { public Connection getConnection() throws Exception {
InitialContext ctx = new InitialContext(); DataSource ds = (DataSource)
ctx.lookup("java:/PostgresDS"); Connection conn = null; Statement stmt
= null; try { conn = ds.getConnection(); } catch (SQLException sqlEx) {
System.out.println("Error connect to pool."); } return conn; } public
String getName(String id) throws Exception { Connection conn = null;
Statement stmt = null; ResultSet rs = null; String name = ""; try {
conn = getConnection(); if ( conn !=null )System.out.println("Get
conecttion. "+ conn.toString()); stmt = conn.createStatement(); if (
stmt !=null )System.out.println("Get Statement. "+ stmt.toString());
String sql = "SELECT * from users where id = ´"+id+"´";
System.out.println("Sql from getId(): "+sql); rs =
stmt.executeQuery(sql); if ( rs !=null )System.out.println("Get result.
"); if (rs.next()){ name = rs.getString("name"); } } catch (Exception
sqlEx) { System.out.println("Error from getName().");
System.out.println("Error from DAO.getName() :" + sqlEx.getMessage());
}finally { if (conn != null) { try { conn.close(); } catch (Exception
sqlEx) { } } } return name; } public String getCountry(String id)
throws Exception { Connection conn = null; Statement stmt = null;
String name = ""; try { conn = getConnection(); stmt =
conn.createStatement(); String sql = "SELECT * from users where id =
´"+id+"´"; System.out.println("Sql from getCountry(): "+sql);
java.sql.ResultSet rs = stmt.executeQuery(sql); if (rs.next()) { name =
rs.getString("Country"); } } catch (SQLException sqlEx) {
System.out.println("Error from getCountry()."); }finally { if (conn !=
null) { try { conn.close(); } catch (Exception sqlEx) { } } } return
name; }}
/*
**
**NewDelegate.java
**
*/
package
Dev.Delegate;import java.lang.*;import Dev.First.*;public class
NewDelegate { Dev.First.FirstSession bean = null; public NewDelegate(
){ try { javax.naming.InitialContext ctx = new
javax.naming.InitialContext(); Object objref =
ctx.lookup("ejb/FirstSession"); Dev.First.FirstSessionHome testBean =
(Dev.First.FirstSessionHome) javax.rmi.PortableRemoteObject.narrow
(objref,Dev.First.FirstSessionHome.class); bean = testBean.create();
System.out.println("From JSP"); } catch (Exception NamingException) {
NamingException.printStackTrace(); } } public String Welcome() { String
msg = ""; try { msg = bean.Welcome(); } catch (Exception
NamingException) { NamingException.printStackTrace(); } return msg; }
public String getName(String id) { String name = ""; try { name =
bean.getName(id); } catch (Exception NamingException) {
NamingException.printStackTrace();} return name; } public String
getCountry(String id) { String country = ""; try { country =
bean.getCountry(id); } catch (Exception NamingException) {
NamingException.printStackTrace();} return country; } }
/*
**
**FirstSession.java
**
*/
package
Dev.First;import java.lang.*;import java.rmi.RemoteException;import
javax.ejb.CreateException;import javax.ejb.EJBException;import
javax.ejb.SessionBean;import javax.ejb.SessionContext;public interface
FirstSession extends javax.ejb.EJBObject{ public String Welcome()
throws java.rmi.RemoteException; public String getName(String id)
throws java.rmi.RemoteException; public String getCountry(String id)
throws java.rmi.RemoteException;}
/*
**
**FirstSessionHome.java
**
*/
package
Dev.First;import java.lang.*;import java.rmi.RemoteException;import
javax.ejb.CreateException;import javax.ejb.EJBException;import
javax.ejb.SessionBean;import javax.ejb.SessionContext;public interface
FirstSessionHome extends javax.ejb.EJBHome{public FirstSession create()
throws javax.ejb.CreateException, java.rmi.RemoteException;}
/*
**
**FirstSessionBean.java
**
*/
package
Dev.First;import java.rmi.RemoteException;import
javax.ejb.CreateException;import javax.ejb.EJBException;import
javax.ejb.SessionBean;import javax.ejb.SessionContext;public class
FirstSessionBean implements SessionBean{public void ejbCreate() throws
CreateException {}public String Welcome(){ String msg="Hello! This My
Session Bean From Jboss."; System.out.println(msg); return msg;}public
String getName(String id){ String name = ""; System.out.println("From
bean before getName :"+ name); try{ Dev.Dao.MysqlDao dao = new
Dev.Dao.MysqlDao(); name = dao.getName(id); System.out.println("From
bean after getName :"+ name); }catch(Exception e){
System.out.println(e.getMessage());} return name;}public String
getCountry(String id){ String country = ""; try{ Dev.Dao.MysqlDao dao =
new Dev.Dao.MysqlDao(); country = dao.getCountry(id); }catch(Exception
e){ } return country;}public void setSessionContext( SessionContext
aContext ) throws EJBException {}public void ejbActivate() throws
EJBException {}public void ejbPassivate() throws EJBException {}public
void ejbRemove() throws EJBException {}}
/*Don´t put the following lines into index.jsp
**
**index.jsp
**
*/Don´t put the above lines into index.jsp
<%@page
language="java" %><% String msg = ""; String msg1 = "";
Dev.Delegate.NewDelegate nn = new Dev.Delegate.NewDelegate(); if
(request.getParameter("id") != null &&
request.getParameter("id") != ""&&
!request.getParameter("id").equals("")){ String id =
request.getParameter("id"); String name = ""; Dev.Dao.MysqlDao dao =
new Dev.Dao.MysqlDao(); name = nn.getName(id); //access database
through session bean //name = dao.getName(id); //access database
directly if(name!= null && !name.equals("")){ msg1 ="Welcome "
+ name +" ! You are from "+ dao.getCountry(id)+ " ."; }else{ msg1
="Please Check Your ID. : " + id; } } msg = nn.Welcome()
;%><html><head><title>Welcome</title></head><body
bgcolor="#FFFFCC"><br> <%= msg %> <br><FORM
ACTION="index.jsp" method="post"><P>Your ID:<INPUT
TYPE="TEXT" NAME="id" size = "10"></P><P><INPUT
TYPE="SUBMIT"
NAME="SUBMIT"></P></FORM><br><br><%=(msg1
== "")? "":msg1 + "<br> <br> <br>Connect to Database
OK." %></body></html>
<!--不要将此以下5行存入文件
**
**ejb-jar.xml
**
-->不要将此以上5行存入文件, 下同.
<?xml
version="1.0" encoding="UTF-8"?><!DOCTYPE ejb-jar PUBLIC "-//Sun
Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN"
"http://java.sun.com/dtd/ejb-jar_2_0.dtd"><ejb-jar>
<description>First</description>
<display-name>First</display-name><enterprise-beans><!--
Session Beans --><session id="MyFirstSession">
<display-name>My First Session Bean</display-name>
<ejb-name>FirstSession</ejb-name>
<home>Dev.First.FirstSessionHome</home>
<remote>Dev.First.FirstSession</remote>
<ejb-class>Dev.First.FirstSessionBean</ejb-class>
<session-type>Stateless</session-type>
<transaction-type>Container</transaction-type></session></enterprise-beans><assembly-descriptor></assembly-descriptor></ejb-jar>
<!--
**
**jboss.xml
**
-->
<?xml
version="1.0" encoding="UTF-8"?><!DOCTYPE jboss PUBLIC
"-//JBoss//DTD JBOSS//EN"
"http://www.jboss.org/j2ee/dtd/jboss.dtd"><jboss><enterprise-beans><session><ejb-name>FirstSession</ejb-name><jndi-name>ejb/FirstSession</jndi-name></session></enterprise-beans><resource-managers></resource-managers></jboss>
<!--
**
**jboss-web.xml
**
-->
<?xml
version="1.0" encoding="UTF-8"?><!DOCTYPE jboss-web PUBLIC
"-//JBoss//DTD Web Application 2.2//EN"
"http://www.jboss.org/j2ee/dtd/jboss-web.dtd"><jboss-web>
<resource-ref>
<res-ref-name>jdbc/PostgresDS</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<jndi-name>java:/PostgresDS</jndi-name>
</resource-ref></jboss-web>
<!--
**
**web.xml
**
-->
<?xml
version="1.0" encoding="ISO-8859-1"?><!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application
2.2//EN""http://java.sun.com/j2ee/dtds/web-app_2_2.dtd"><web-app><resource-ref>
<description>Postgresql driver</description>
<res-ref-name>jdbc/PostgresDS</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth></resource-ref></web-app>
<!--
**
**application.xml
**
-->
<?xml
version="1.0"
encoding="ISO-8859-1"?><application><display-name>First</display-name><module><web><web-uri>First.war</web-uri><context-root>/First</context-root></web></module><module><ejb>First.jar</ejb></module></application>
编译JAVA源程序,生成class文件.
进入JAVA源程序目录, 运行:
javac -classpath %classpath%;%jboss%serverdefaultdeployFirst.earFirst.jar *.java
或者
javac -classpath %jboss%serverdefaultdeployFirst.earFirst.jar;%jboss%clientjboss-j2ee.jar *.java
Copy 目录First.ear to jbossserverdefaultdeploy.
打开浏览器输入地址
http://localhost:8080/First
到此, 在浏览器看到: Hello! This My Session Bean From Jboss.
说明这个EJB工作了.
如果按按钮, 没反应或出错. 原因没安装配置数据库, 下面安装配置Postgres数据库
For Windows2000
下载 PgSQL731wina1.exe
(http://www.postgresql.org),
Finally you will see the next line, you need enter the password for Administrator
最后你将看下一个行,你必须为用户Administrator输入password.
********************
Enter password of user `.Administrator´:123456
********************
记下此password, 我的口令是123456.
从开始菜单 > Programm > PostgresSQL > Adjust PostgresSQL Configuration file
它将在Wordpad中打开PostgresSQL Configuration文件, 找到下列行,
#
# Connection Parameters
#
#tcpip_socket = false
#ssl = false
#max_connections = 32
#superuser_reserved_connections = 2
#port = 5432
修改编辑:
#
# Connection Parameters
#
tcpip_socket = true
#ssl = false
#max_connections = 32
#superuser_reserved_connections = 2
port = 5432
接着，保存文件.
起动PostgresSQL服务器:
开始菜单>Programm>PostgresSQL>Utilies>Start PostgresSQL server
起动命令行:
开始菜单>Programm>PostgresSQL>Utilies>Command Shell
执行下列命令,准备数据,
Administrator@SAN /
$ dir
$ cd bin
$ createdb test
$ psql test
test=# create table users
test-# (name varchar(20),
test(# id varchar(20),
test(# country varchar(20));
test=# insert into users values (´Sam´, ´123´, ´China´);
test=# insert into users values (´Tom´, ´321´, ´USA´);
test=# insert into users values (´Sean´, ´231´, ´France´);
test=# select * from users;
name | id | country
------+-----+---------
Sam | 123 | China
Tom | 321 | USA
Sean | 231 | France
(3 rows)
test=#
到此, 数据准备就绪.
For RedHat:
以root登陆, 执行下列命令,准备数据,
mkdir /usr/local/pgsql/data
chown postgres /usr/local/pgsql/data
su - postgres
/usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data
Open and edit /usr/local/pgsql/data/pg_hba.conf
local all trust
host all 127.0.0.1 255.255.255.255 trust
just delete #, and save.
[root@localhost root]# su - postgres
-bash-2.05b$ /usr/bin/postmaster -i -D /usr/local/pgsql/data >logfile 2>&1 &
-bash-2.05b$ /usr/bin/createdb test
-bash-2.05b$ /usr/local/pgsql/bin/psql test
test=# .......the following same as Windows2000
到此, 数据准备就绪.
执行shutdown.bat or shutdown.sh, 停止Jboss Server.
找到JDBC drive.
为
了在Jboss中使用连接池,需要拷贝jdbc drive 到Jboss/server/default/deploy , 在linux
我们能找到/usr/share/pgsql/pgjdbc2.jar,在wondows2000,我们能找到
PostgreSQLusrsharepostgresqljavapostgresql.jar
把其中之一复制到Jboss/server/default/deploy
配置Jboss
(1) 复制 $Jboss/examples/jca/postgres-service.xml 到 $Jboss/server/default/deploy/
(2) 打开编辑Jboss/server/default/deploy/postgres-service.xml
<attribute name="JndiName">PostgresDS</attribute>
<attribute name="ManagedConnectionFactoryProperties">
<properties>
<config-property name="ConnectionURL" type="java.lang.String">jdbc:postgresql://localhost/test</config-property>
<config-property name="DriverClass" type="java.lang.String">org.postgresql.Driver</config-property>
<!--set these only if you want only default logins, not through JAAS -->
<config-property name="UserName" type="java.lang.String">Administrator</config-property>
<config-property name="Password" type="java.lang.String">123456</config-property>
</properties>
In my example, set Username Administrator, password 123456 for windows 2000
set Username Postgres, no password for Linux.
在我的例子中，
windows2000, 用户:Administrator，password:123456
Linux(RH8.0), 用户:Postgres, 没有password
因
为PostgresSQL和windows2000使用不同的default用户名,所以在linux和window2000中这文件不同.当然，你可以
加相同的PostgresSQL用户名和password在linux和window2000中, 这样这文件就相同了.
保存文件.
(3) 打开编辑 $Jboss/server/default/conf/standardjbosscmp-jdbc.xml
找到:
<datasource>java:/DefaultDS</datasource>
<datasource-mapping>Hypersonic SQL</datasource-mapping>
加入:
<datasource>java:/PostgresDS</datasource>
<datasource-mapping>Postgres</datasource-mapping>
保存文件.
(4) open and edit $Jboss/server/default/conf/standardjaws.xml
找到:
<datasource>java:/DefaultDS</datasource>
<type-mapping>Hypersonic SQL</type-mapping>
<debug>false</debug>
加入:
<datasource>java:/PostgresDS</datasource>
<type-mapping>Postgres</type-mapping>
<debug>false</debug>
保存文件.
现在重起JBoss.
打开浏览器输入地址
http://localhost:8080/First
输入ID,按按钮.