JBuilder是一個開放的Java IDE,它集成了Tomcat、Weblogic等服務器。雖然JDK、Tomcat、Weblogic不斷升級,我們仍可以在JBuilder中使用它們的最新版本。由於Tomcat服務器的配置比較復雜,習慣了Windows平台的程序員常常對Tomcat的使用感到困惑。本文給出了一個使用Tomcat環境下的數據庫連接池Database Connection Pool (DBCP) 的例子,說明了用JBuilder開發Web應用的一般步驟,並回答了一些經常遇到的問題。
JBuilder2005所帶JDK的版本是1.4.2_04-b05,其文件放在目錄JBuilder_HOME\jdk1.4下,Tomcat的最新版本是5.0.27,其文件放在目錄JBuilder_HOME\thirdparty\ jakarta-tomcat-5.0.27下。下面首先給出給出了一個使用Tomcat環境下的數據庫連接池Database Connection Pool (DBCP) 的例子。
1.File-New Project新建工程文件,輸入工程文件名稱myWeb和目錄C:\myWeb
2.Project-Project Properties設置工程文件的屬性,選擇Tomcat為服務器
3.File-New新建Web Module(WAR)
輸入Web Module的名稱DBTest和目錄DBTest
4.File-New新建JSP,輸入jsp文件的名稱test.jsp,產生test.jsp文件後修改test.jsp的內容
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>
將會生成一個名稱為test的runtime configuration。
選Run-Configurations-Edit可修改runtime configuration,特別是可以指定服務器的端口號和是否自動搜索為被占用的端口。
5.File-New Class,輸入類名DBTest和包名foo,產生DBTest.java文件後修改它的內容
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的內容
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運行應用,myWeb目錄中將會生成Tomcat子目錄,其中包含了conf子目錄,
在Tomcat_HOME\conf\Catalina\localhost目錄中生成了DBTest.xml文件
8.將myWeb\Tomcat\conf目錄中的文件server8080.xml加入工程文件,修改server8080.xml的內容
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.將JDBC驅動放在C:\Borland\JBuilder2005\thirdparty\jakarta-tomcat-5.0.27\common\lib目錄中
10.在SQL Server中建立數據庫test,數據庫表文件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
輸入幾條記錄作為測試數據。
11.F9
12.在c:\myWebmulu中建立批處理文件startup.bat和shutdown.bat內容分別如下:
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.運行startup.bat,在浏覽器輸入http://localhost:8080/DBTest/test.jsp
如何部署Web應用?
1.打包生成war文件
2.將DBTest.war拷貝到Tomcat_HOME\webapps
3.在Tomcat_HOME\conf\Catalina\localhost目錄中建立文件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.啟動Tomcat,DBTest.war將會解壓到Tomcat_HOME\webapps\DBTest,並且在Tomcat_HOME\work\Catalina\localhost目錄中生成DBTest目錄
為什麼不能生成war文件?
在proterties for Web Module對話框中設置與Build有關的屬性Build Web archive。
如何在Web應用中加入目錄和文件?
右擊Module directory,在彈出的菜單中選擇New-directory,輸入目錄名稱;或右擊擬在其中建立文件的目錄,在彈出的菜單中選擇New-File,選擇文件類型,輸入文件名。注意這樣加入的文件只能是指定的文件類型。這樣加入的目錄和文件都會打包到war文件中。
如何加入其它類型的文件?
可以將文件拷貝到指定的目錄,在proterties for Web Module對話框中設置屬性Content,選擇include all classes and resources,這樣也可以將加入的文件打包到war文件中。
如何使用指定的JDK?
選擇菜單Tools-Configure-JDKs,在彈出的對話框中按New按鈕,然後選擇JDK的路徑。
選擇菜單Project-Project Properties,在彈出的對話框中選擇加入的JDK。
如何使用指定的Tomcat?
選擇菜單Enterprise-Configure Servers,在彈出的對話框中選擇Tomcat5.0後按Copy按鈕,
選擇Copy產生的服務器Copy of Tomcat 5.0,選擇Home Directory
選擇菜單Project-Project Properties,在彈出的對話框中設置屬性server,選擇加入的Tomcat服務器。