一.使用JB2005连接Tomcat的连接池总是连接不通的原因主要有下面两点。
1.错误：Cannot create JDBC driver of class '' for connect URL 'null', cause:
出现条件：使用手动配置连接池子(及修改 server.xml 文件.)
原因：不清楚。
2.错误：NameNotFoundException: Name jdbc is not bound in this Context
出现条件：使用Tomcat的web页面配置连接池。在\conf\Catalina\localhost下的相应文件添 <ResourceLink /> 如： <ResourceLink global="joConnPool" name="joConnPool" type="javax.sql.DataSource"/>的朋友容易出现这种错误。
原因：JB2005启动tomcat的时候会自动将\conf\Catalina\localhost下和自己相应的文件修改为默认。也就是说你添加的<ResourceLink/>没有起到作用，当然会出现NameNotFoundException: Name jdbc is not bound in this Context 这个错误。
二.正确使用JB2005连接Tomcat的连接池分析：
首先应该是在JB2005自动生成的 server8080.xml (根据自己配置端口号有所不同) 添加到JB2005工程里面，然后在里面配置连接池。而且必须手动配置。如果有兄弟手动配置过server.xml就将server.xml里面的<Context/>拷贝到 server8080.xml中覆盖以前的<Context/>(注意要删除server.xml里面的那一条注释才起作用)。然后使用JB2005重启TOMCAT就OK了。具体实例子见下面：
三.使用JB2005连接Tomcat的连接池实例。(实例原出处 http://www.javajia.com/ 原地址 http://www.javajia.com/article.php?id=918)
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
＜?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 完成./.
＜?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 完成./.
＜?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 完成./.
