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_HOMEjdk1.4下,Tomcat的最新版本是5.0.27,其文件放在目录JBuilder_HOME hirdparty 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_HOMEconfCatalinalocalhost目录中生成了DBTest.xml文件 
  8. 将myWebTomcatconf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:myWebTomcatwebapps" autoDeploy="false" debug="0" deployXML="false" name="localhost" unpackWARs="false"> 
  <Context path="/DBTest" docBase="C:myWebDBTest" debug="5" reloadable="true" crossContext="true" workDir="C:myWebTomcatworkDBTest"> 
  <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:BorlandJBuilder2005 hirdpartyjakarta-tomcat-5.0.27commonlib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:BorlandJBuilder2005jdk1.4injavaw -classpath "C:BorlandJBuilder2005 hirdpartyjakarta-tomcat-5.0.27inootstrap.jar;C:BorlandJBuilder2005jdk1.4lib ools.jar" "-Dcatalina.home=C:/Borland/JBuilder2005/thirdparty/jakarta-tomcat-5.0.27" org.apache.catalina.startup.Bootstrap -config "C:myWebTomcatconfserver8080.xml" start 
  Shutdown.bat: 
  C:BorlandJBuilder2005jdk1.4injavaw -classpath "C:BorlandJBuilder2005 hirdpartyjakarta-tomcat-5.0.27inootstrap.jar;C:BorlandJBuilder2005jdk1.4lib ools.jar" "-Dcatalina.home=C:/Borland/JBuilder2005/thirdparty/jakarta-tomcat-5.0.27" org.apache.catalina.startup.Bootstrap -config "C:myWebTomcatconfserver8080.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_HOMEwebapps 
  3. 在Tomcat_HOMEconfCatalinalocalhost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_HOMEwebappsDBTest,并且在Tomcat_HOMEworkCatalinalocalhost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