Cannot load JDBC Driver class 'null' with TOMCAT

[Frank Marx]

Hi,

I have a really strange problem with TOMCAT 4.1.24 using a JNDI Datasource.
I have the following server.xml in which I definde the DataSource in the
DefaultContext
so I don't need to make any changes in the web.xml because this is generated
dynamically every time
the web-app. is deployed.

Here is the server.xml I'm using:

<DefaultContext useNaming="true">

<Environment name="maxExemptions" value="10"
type="java.lang.Integer" override="true"/>

<Resource name="jdbc/myDB"
auth="Container"
description="This is my test db"
type="javax.sql.DataSource" />

<ResourceParams name="jdbc/myDB">
<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>frank</value>
</parameter>
<parameter>
<name>password</name>
<value>frank</value>
</parameter>

<!-- Class name for mm.mysql JDBC driver -->
<parameter>
<name>driverClassName</name>
<value>org.gjt.mm.mysql.Driver</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:mysql://localhost:3306/mydb</value>
</parameter>
</ResourceParams>

</DefaultContext>

I also copied the JAR with the MySQL Driver in the following directories of
TOMCAT and restarted TOMCAT:

- server/lib
-common/lib
-shared/lib

I can load the MySQL-Driver when I use Class.forName - Construct but this is
not what I really want.

Right now I don't really know what to do - it just makes no sense to me at
all.

Any help is greatly appreciated.

Kind regards,

Frank Marx

 

[=?ISO-8859-1?Q?Mario_M=E9ndez_Villegas?=]

Hi Frank,

Well the sever.xml is correct, but you need
to change your web.xml, i have the following code
in mine:

<resource-ref>
<description>
Resource reference to a factory for java.sql.Connection
instances that may be used for talking to a particular
database that is configured in the server.xml file.
</description>
<res-ref-name>
jdbc/intranet
</res-ref-name>
<res-type>
javax.sql.DataSource
</res-type>
<res-auth>
Container
</res-auth>
</resource-ref>

Best regards,
Mario Méndez Villegas