本文給出了一個使用Tomcat環(huán)境下的數(shù)據(jù)庫連接池Database Connection Pool (DBCP) 的例子,說明了用JBuilder2005開發(fā)Web應(yīng)用的一般步驟:
JBuilder是一個開放的Java IDE,它集成了Tomcat、Weblogic等服務(wù)器。雖然JDK、Tomcat、Weblogic不斷升級,我們?nèi)钥梢栽贘Builder中使用它們的最新版本。由于Tomcat服務(wù)器的配置比較復雜,習慣了Windows平臺的程序員常常對Tomcat的使用感到困惑。本文給出了一個使用Tomcat環(huán)境下的數(shù)據(jù)庫連接池Database Connection Pool (DBCP) 的例子,說明了用JBuilder開發(fā)Web應(yīng)用的一般步驟,并回答了一些經(jīng)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(huán)境下的數(shù)據(jù)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(shè)置工程文件的屬性,選擇Tomcat為服務(wù)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(chǎn)生test.jsp文件后修改test.jsp的內(nèi)容
Test.jsp:
<%@ page contentType="text/html; charset=Big5" %> <html> <head> 。紅itle>DB Test</title> </head> <body> <% foo.DBTest tst = new foo.DBTest(); tst.init(); %> 。糷2>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(wù)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(chǎn)生DBTest.java文件后修改它的內(nèi)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(nèi)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"> 。糳escription>MySQL Test App</description> <resource-ref> 。糳escription>DB Connection</description> <res-ref-name>jdbc/TestDB</res-ref-name> 。紃es-type>javax.sql.DataSource</res-type> <res-auth>Container</res-auth> 。/resource-ref> </web-app> |
7. F9運行應(yīng)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(nèi)容
server8080.xml:
<?xml version="1.0" encoding="UTF-8"?> <Server debug="0" port="8081" shutdown="SHUTDOWN"> <Service name="Catalina"> 。糃onnector acceptCount="10" connectionTimeout="60000" debug="0" maxThreads="75" minSpareThreads="5" port="8080"/> 。糆ngine debug="0" defaultHost="localhost" name="Catalina"> 。糎ost appBase="C:\myWeb\Tomcat\webapps" autoDeploy="false" debug="0" deployXML="false" name="localhost" unpackWARs="false"> 。糃ontext 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"/> 。糝esource name="jdbc/TestDB" auth="Container" type="javax.sql.DataSource"/> 。糝esourceParams name="jdbc/TestDB"> <parameter> 。糿ame>factory</name> 。紇alue>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. --> 。紁arameter> <name>maxActive</name> 。紇alue>100</value> 。/parameter> 。!-- Maximum number of idle dB connections to retain in pool. Set to 0 for no limit. --> <parameter> 。糿ame>maxIdle</name> 。紇alue>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. --> 。紁arameter> 。糿ame>maxWait</name> <value>10000</value> 。/parameter> <!-- MySQL dB username and password for dB connections --> 。紁arameter> <name>username</name> 。紇alue>sa</value> 。/parameter> 。紁arameter> <name>password</name> 。紇alue>topcomputer</value> </parameter> 。!-- Class name for mm.mysql JDBC driver --> 。紁arameter> 。糿ame>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. --> 。紁arameter> <name>url</name> <value>jdbc:microsoft:sqlserver://nt04:1433;DatabaseName=test</value> 。/parameter> </ResourceParams> </Context> </Host> </Engine> </Service> </Server> |
9. 將JDBC驅(qū)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(shù)據(jù)庫test,數(shù)據(jù)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(shù)據(jù)。
11. F9
12. 在c:\myWebmulu中建立批處理文件startup.bat和shutdown.bat內(nèi)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,在瀏覽器輸入http://localhost:8080/DBTest/test.jsp
如何部署Web應(yīng)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">
。紁arameter>
。糿ame>factory</name>
。紇alue>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.
-->
。紁arameter>
<name>maxActive</name>
。紇alue>100</value>
。/parameter>
<!--
Maximum number of idle dB connections to retain in pool.
Set to 0 for no limit.
-->
。紁arameter>
。糿ame>maxIdle</name>
。紇alue>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>
。糿ame>maxWait</name>
<value>10000</value>
。/parameter>
<!-- MySQL dB username and password for dB connections -->
。紁arameter>
。糿ame>username</name>
<value>sa</value>
。/parameter>
<parameter>
。糿ame>password</name>
。紇alue>topcomputer</value>
</parameter>
。!-- Class name for mm.mysql JDBC driver -->
。紁arameter>
。糿ame>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.
-->
。紁arameter>
<name>url</name>
。紇alue>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,并且在Tomcat_HOME\work\Catalina\localhost目錄中生成DBTest目錄
為什么不能生成war文件?
在proterties for Web Module對話框中設(shè)置與Build有關(guān)的屬性Build Web archive。
如何在Web應(yīng)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(shè)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,然后選擇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后按Copy按鈕,
選擇Copy產(chǎn)生的服務(wù)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(shè)置屬性server,選擇加入的Tomcat服務(wù)器