利用JBuilder2005开发Web应用程序

2010-08-28 10:44:42来源:西部e网作者:

  本文给出了一个使用Tomcat环境下的数据库连接池Database Connection Pool (DBCP) 的例子,说明了用JBuilder2005开发Web应用的一般步骤:

  JBuilder是一个开放的Java IDE,它集成了Tomcat、Weblogic等服务器。虽然JDK、Tomcat、Weblogic不断升级,我们仍可以在JBuilder中使用它们的最新版本。由于Tomcat服务器的配置比较复杂,习惯了Windows平台的程序员常常对Tomcat的使用感到困惑。本文给出了一个使用Tomcat环境下的数据库连接池Database Connection Pool (DBCP) 的例子,说明了用JBuilder开发Web应用的一般步骤,并回答了一些经常遇到的问题。

  JBuilder2005所带JDK的版本是1.4.2_04-b05,其文件放在目录JBuilder_HOME\jdk1.4下,Tomcat的最新版本是5.0.27,其文件放在目录JBuilder_HOME\thirdparty\ jakarta-tomcat-5.0.27下。下面首先给出给出了一个使用Tomcat环境下的数据库连接池Database Connection Pool (DBCP) 的例子。

  1. File-New Project新建工程文件,输入工程文件名称myWeb和目录C:\myWeb

  2. Project-Project Properties设置工程文件的属性,选择Tomcat为服务器

  3. File-New新建Web Module(WAR)

  输入Web Module的名称DBTest和目录DBTest

  4. File-New新建JSP,输入jsp文件的名称test.jsp,产生test.jsp文件后修改test.jsp的内容

  Test.jsp:

<%@ page contentType="text/html; charset=Big5" %>
<html>
<head>
 <title>DB Test</title>
</head>
<body>
 <%
  foo.DBTest tst = new foo.DBTest();
  tst.init();
 %>
 <h2>Results</h2>
 Foo <%= tst.getFoo() %><br/>
 Bar <%= tst.getBar() %>
</body>
</html>


  将会生成一个名称为test的runtime configuration。

  选Run-Configurations-Edit可修改runtime configuration,特别是可以指定服务器的端口号和是否自动搜索为被占用的端口。

  5. File-New Class,输入类名DBTest和包名foo,产生DBTest.java文件后修改它的内容

DBTest.java

package foo;

import javax.naming.*;
import javax.sql.*;
import java.sql.*;
public class DBTest {
 String foo = "Not Connected";
 int bar = -1;
 public void init() {
  try{
   Context ctx = new InitialContext();
   if(ctx == null )
    throw new Exception("Boom - No Context");
    DataSource ds =(DataSource)ctx.lookup("java:comp/env/jdbc/TestDB");
    if (ds != null) {
     Connection conn = ds.getConnection();
     if(conn != null) {
      foo = "Got Connection "+conn.toString();
      Statement stmt = conn.createStatement();
      ResultSet rst =stmt.executeQuery("select id, foo, bar from testdata");
      if(rst.next()) {
       foo=rst.getString(2);
       bar=rst.getInt(3);
      }
      conn.close();
     }
    }
   }catch(Exception e) {
    e.printStackTrace();
   }
  }
 public String getFoo() { return foo; }
 public int getBar() { return bar;}
}


  6. 修改web.xml的内容

  web.xml:

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

<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4">

 <description>MySQL Test App</description>
 <resource-ref>
  <description>DB Connection</description>
  <res-ref-name>jdbc/TestDB</res-ref-name>
  <res-type>javax.sql.DataSource</res-type>
  <res-auth>Container</res-auth>
 </resource-ref>
</web-app>


  7. F9运行应用,myWeb目录中将会生成Tomcat子目录,其中包含了conf子目录,

  在Tomcat_HOME\conf\Catalina\localhost目录中生成了DBTest.xml文件

  8. 将myWeb\Tomcat\conf目录中的文件server8080.xml加入工程文件,修改server8080.xml的内容

  server8080.xml:

<?xml version="1.0" encoding="UTF-8"?>
<Server debug="0" port="8081" shutdown="SHUTDOWN">
<Service name="Catalina">
 <Connector acceptCount="10" connectionTimeout="60000" debug="0" maxThreads="75" minSpareThreads="5" port="8080"/>
 <Engine debug="0" defaultHost="localhost" name="Catalina">
 <Host appBase="C:\myWeb\Tomcat\webapps" autoDeploy="false" debug="0" deployXML="false" name="localhost" unpackWARs="false">

 <Context path="/DBTest" docBase="C:\myWeb\DBTest" debug="5" reloadable="true" crossContext="true" workDir="C:\myWeb\Tomcat\work\DBTest">

 <Logger className="org.apache.catalina.logger.FileLogger" prefix="localhost_DBTest_log." suffix=".txt" timestamp="true"/>

 <Resource name="jdbc/TestDB" auth="Container" type="javax.sql.DataSource"/>

 <ResourceParams name="jdbc/TestDB">
 <parameter>
  <name>factory</name>
  <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
 </parameter>
 <!--
  Maximum number of dB connections in pool. Make sure you
  configure your mysqld max_connections large enough to handle
  all of your db connections. Set to 0 for no limit.
 -->
 <parameter>
  <name>maxActive</name>
  <value>100</value>
 </parameter>
 <!--
  Maximum number of idle dB connections to retain in pool.
  Set to 0 for no limit.
 -->
 <parameter>
  <name>maxIdle</name>
  <value>30</value>
 </parameter>
 <!--
  Maximum time to wait for a dB connection to become available
  in ms, in this example 10 seconds. An Exception is thrown if
  this timeout is exceeded. Set to -1 to wait indefinitely.
 -->
 <parameter>
  <name>maxWait</name>
  <value>10000</value>
 </parameter>
 <!-- MySQL dB username and password for dB connections -->
 <parameter>
  <name>username</name>
  <value>sa</value>
 </parameter>
 <parameter>
  <name>password</name>
  <value>topcomputer</value>
 </parameter>
 <!-- Class name for mm.mysql JDBC driver -->
 <parameter>
  <name>driverClassName</name>
  <value>com.microsoft.jdbc.sqlserver.SQLServerDriver</value>
 </parameter>
 <!--
  The JDBC connection url for connecting to your MySQL dB.
  The autoReconnect=true argument to the url makes sure that the
  mm.mysql JDBC Driver will automatically reconnect if mysqld closed the
  connection. mysqld by default closes idle connections after 8 hours.
 -->
 <parameter>
  <name>url</name>
  <value>jdbc:microsoft:sqlserver://nt04:1433;DatabaseName=test</value>
 </parameter>
</ResourceParams>
</Context>
</Host>
</Engine>
</Service>
</Server>


  9. 将JDBC驱动放在C:\Borland\JBuilder2005\thirdparty\jakarta-tomcat-5.0.27\common\lib目录中

  10. 在SQL Server中建立数据库test,数据库表文件testdata

  creatTable.sql:

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[testdata]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[testdata]
GO

CREATE TABLE [dbo].[testdata] (
 [id] [int] NOT NULL ,
 [foo] [varchar] (50) COLLATE Chinese_Taiwan_Stroke_CI_AS NULL ,
 [bar] [int] NOT NULL
) ON [PRIMARY]

GO


  输入几条记录作为测试数据。



  11. F9

  12. 在c:\myWebmulu中建立批处理文件startup.bat和shutdown.bat内容分别如下:

  startup.bat:

C:\Borland\JBuilder2005\jdk1.4\bin\javaw -classpath "C:\Borland\JBuilder2005\thirdparty\jakarta-tomcat-5.0.27\bin\bootstrap.jar;C:\Borland\JBuilder2005\jdk1.4\lib\tools.jar" "-Dcatalina.home=C:/Borland/JBuilder2005/thirdparty/jakarta-tomcat-5.0.27" org.apache.catalina.startup.Bootstrap -config "C:\myWeb\Tomcat\conf\server8080.xml" start

Shutdown.bat:

C:\Borland\JBuilder2005\jdk1.4\bin\javaw -classpath "C:\Borland\JBuilder2005\thirdparty\jakarta-tomcat-5.0.27\bin\bootstrap.jar;C:\Borland\JBuilder2005\jdk1.4\lib\tools.jar" "-Dcatalina.home=C:/Borland/JBuilder2005/thirdparty/jakarta-tomcat-5.0.27" org.apache.catalina.startup.Bootstrap -config "C:\myWeb\Tomcat\conf\server8080.xml" stop

  13. 运行startup.bat,在浏览器输入http://localhost:8080/DBTest/test.jsp

  如何部署Web应用?

  1. 打包生成war文件

  2. 将DBTest.war拷贝到Tomcat_HOME\webapps

  3. 在Tomcat_HOME\conf\Catalina\localhost目录中建立文件DBTest.xml

DBTest.xml

<!--
 Context configuration file for the Tomcat Administration Web App
$Id: admin.xml,v 1.2 2002/07/23 12:13:05 remm Exp $

-->

<Context path="/DBTest" docBase="/DBTest" debug="5" reloadable="true" crossContext="true" workDir="../work/DBTest">

<Logger className="org.apache.catalina.logger.FileLogger" prefix="localhost_DBTest_log." suffix=".txt" timestamp="true"/>

<Resource name="jdbc/TestDB" auth="Container" type="javax.sql.DataSource"/>
<ResourceParams name="jdbc/TestDB">
 <parameter>
  <name>factory</name>
  <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
 </parameter>
 <!--
  Maximum number of dB connections in pool. Make sure you
  configure your mysqld max_connections large enough to handle
  all of your db connections. Set to 0 for no limit.
 -->
 <parameter>
  <name>maxActive</name>
  <value>100</value>
 </parameter>
 <!--
  Maximum number of idle dB connections to retain in pool.
  Set to 0 for no limit.
 -->
 <parameter>
  <name>maxIdle</name>
  <value>30</value>
 </parameter>
 <!--
  Maximum time to wait for a dB connection to become available
  in ms, in this example 10 seconds. An Exception is thrown if
  this timeout is exceeded. Set to -1 to wait indefinitely.
 -->
 <parameter>
  <name>maxWait</name>
  <value>10000</value>
 </parameter>
 <!-- MySQL dB username and password for dB connections -->
 <parameter>
  <name>username</name>
  <value>sa</value>
 </parameter>
 <parameter>
  <name>password</name>
  <value>topcomputer</value>
 </parameter>
 <!-- Class name for mm.mysql JDBC driver -->
 <parameter>
  <name>driverClassName</name>
  <value>com.microsoft.jdbc.sqlserver.SQLServerDriver</value>
 </parameter>
 <!--
  The JDBC connection url for connecting to your MySQL dB.
  The autoReconnect=true argument to the url makes sure that the
  mm.mysql JDBC Driver will automatically reconnect if mysqld closed the
  connection. mysqld by default closes idle connections after 8 hours.
 -->
 <parameter>
  <name>url</name>
  <value>jdbc:microsoft:sqlserver://nt04:1433;DatabaseName=test</value>
 </parameter>
</ResourceParams>
</Context>

  4. 启动Tomcat,DBTest.war将会解压到Tomcat_HOME\webapps\DBTest,并且在Tomcat_HOME\work\Catalina\localhost目录中生成DBTest目录

  为什么不能生成war文件?

  在proterties for Web Module对话框中设置与Build有关的属性Build Web archive。

  如何在Web应用中加入目录和文件?

  右击Module directory,在弹出的菜单中选择New-directory,输入目录名称;或右击拟在其中建立文件的目录,在弹出的菜单中选择New-File,选择文件类型,输入文件名。注意这样加入的文件只能是指定的文件类型。这样加入的目录和文件都会打包到war文件中。

  如何加入其它类型的文件?

  可以将文件拷贝到指定的目录,在proterties for Web Module对话框中设置属性Content,选择include all classes and resources,这样也可以将加入的文件打包到war文件中。

  如何使用指定的JDK?

  选择菜单Tools-Configure-JDKs,在弹出的对话框中按New按钮,然后选择JDK的路径。

  选择菜单Project-Project Properties,在弹出的对话框中选择加入的JDK。

  如何使用指定的Tomcat?

  选择菜单Enterprise-Configure Servers,在弹出的对话框中选择Tomcat5.0后按Copy按钮,

  选择Copy产生的服务器Copy of Tomcat 5.0,选择Home Directory

  选择菜单Project-Project Properties,在弹出的对话框中设置属性server,选择加入的Tomcat服务器

关键词:JBuilder