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From John Walstra <jwals...@spoonserver.com>
Subject Re: Cannot load JDBC driver class 'null'
Date Mon, 23 Sep 2002 04:29:36 GMT
>From the mysql-connector-java-2.0.14 README ...

--
A simple connection example looks like:

  Class.forName("com.mysql.jdbc.Driver").newInstance();

  java.sql.Connection conn;

  conn = DriverManager.getConnection(
    "jdbc:mysql://localhost/test?user=blah&password=blah");
--

And if I un-jar their jar file, I can find it. There is also 
"org.gjt.mm.mysql.Driver",  which also returns the same Exception. I think 
"org.gjt.mm.mysql.Driver" exists to be back-wards compatible. That is also 
the driver class they use in the JNDI Datasource HOWTO.

On Sunday 22 September 2002 11:14 pm, Jacob Kjome wrote:
> Yes, it should find it.  Have you verified that the class in the
> driverClassName element actually does exist in that package in the jar file
> you just mentioned?
>
> Jake
>
> At 10:56 PM 9/22/2002 -0500, you wrote:
> >I do have mysql-connector-java-2.0.14-bin.jar in the common/lib directory.
> >Shouldn't it find the correct class being there?
> >
> >On Sunday 22 September 2002 10:39 pm, Kwok Peng Tuck wrote:
> > > Are you actually using the mysql driver? Cause if it says loading
> > > driver null, means there isn't one.
> > >
> > > John Walstra wrote:
> > > >I'm trying to set up a JNDI connection to MySQL. I'm using the binary
> > > > release of 4.1.11 with 4.0.4's jasper-compiler.jar and
> > > > jasper-runtime.jar. I'm also using mysql-connector-java-2.0.14.
> > > >
> > > >It's very similar to this thread
> > > >http://www.mail-archive.com/tomcat-user@jakarta.apache.org/msg64346.ht
> > > >ml , however I still can't get mine working after reading that thread.
> > > > I've basically followed (cut and paste) the JNDI Datasource HOWTO,
> > > > http://jakarta.apache.org/tomcat/tomcat-4.1-doc/jndi-datasource-examp
> > > >les-h owto.html .
> > > >
> > > >Here is the Context section of my server.xml
> > > >
> > > >        <Context path="/jkw"
> > > >             docBase="/usr/local/web/meta-htdocs/JWALSTRA/htdocs/jsp"
> > > >                debug="5" useNaming="true"
> > > >                reloadable="true" crossContext="true">
> > > >
> > > >             <Logger className="org.apache.catalina.logger.FileLogger"
> > > >                     prefix="jkw_log." suffix=".txt"
> > > >                     timestamp="true"/>
> > > >
> > > >             <Resource name="jdbc/JKW"
> > > >                     auth="Container"
> > > >                     type="javax.sql.DataSource"/>
> > > >
> > > >             <ResourceParams name="jdbc/JKW">
> > > >                     <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>nobody</value>
> > > >                     </parameter>
> > > >                     <parameter>
> > > >                             <name>password</name>
> > > >                             <value></value>
> > > >                     </parameter>
> > > >
> > > >                     <!-- Class name for mm.mysql JDBC driver -->
> > > >                     <parameter>
> > > >                             <name>driverClassName</name>
> > > >                             <value>com.mysql.jdbc.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/jkw?autoReconnect=true</value>
> >
> > > >                     </parameter>
> > > >             </ResourceParams>
> > > >        </Context>
> > > >
> > > >Here is my web.xml
> > > >
> > > ><?xml version="1.0" encoding="ISO-8859-1"?>
> > > >
> > > ><!DOCTYPE web-app
> > > >    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
> > > >    "http://java.sun.com/dtd/web-app_2_3.dtd">
> > > >
> > > ><web-app>
> > > >
> > > >  <taglib>
> > > >    <taglib-uri>
> > > >      /orataglib
> > > >    </taglib-uri>
> > > >    <taglib-location>
> > > >      /WEB-INF/tlds/orataglib_1_0_3.tld
> > > >    </taglib-location>
> > > >  </taglib>
> > > >
> > > >  <taglib>
> > > >    <taglib-uri>
> > > >      /jkw
> > > >    </taglib-uri>
> > > >    <taglib-location>
> > > >      /WEB-INF/tlds/jkw-1.0.tld
> > > >    </taglib-location>
> > > >  </taglib>
> > > >
> > > >  <resource-ref>
> > > >    <description>MySQL DB Connection</description>
> > > >    <res-ref-name>jdbc/JKW</res-ref-name>
> > > >    <res-type>javax.sql.DataSource</res-type>
> > > >    <res-auth>Container</res-auth>
> > > >  </resource-ref>
> > > >
> > > ></web-app>
> > > >
> > > >My common/lib directory ... (jasper* is from 4.0.4)
> > > >
> > > >-rw-r--r--    1 root     root        45386 Sep 19 08:30 activation.jar
> > > >-rw-r--r--    1 root     root       716139 Sep 19 08:30 ant.jar
> > > >-rw-r--r--    1 root     root        90503 Sep 19 08:30
> > > >commons-collections.jar
> > > >-rw-r--r--    1 root     root        62998 Sep 19 08:30
> > > > commons-dbcp.jar -rw-r--r--    1 root     root        16910 Sep 19
> > > > 08:30
> > > >commons-logging-api.jar
> > > >-rw-r--r--    1 root     root        28930 Sep 19 08:30
> > > > commons-pool.jar -rw-r--r--    1 root     root       210191 Sep 22
> > > > 21:40
> > > > jasper-compiler.jar -rw-r--r--    1 root     root        67077 Sep 22
> > > > 21:40 jasper-runtime.jar -rw-r--r--    1 root     root        84854
> > > > Sep 19 08:30 jdbc2_0-stdext.jar -rw-r--r--    1 root     root       
> > > > 98496 Sep 19 08:30 jndi.jar
> > > >-rw-r--r--    1 root     root         8674 Sep 19 08:30 jta.jar
> > > >-rw-r--r--    1 root     root       280984 Sep 19 08:30 mail.jar
> > > >-rw-r--r--    1 root     root       125961 Sep 22 21:27
> > > >mysql-connector-java-2.0.14-bin.jar
> > > >-rw-r--r--    1 root     root        28664 Sep 19 08:30
> > > > naming-common.jar -rw-r--r--    1 root     root        18222 Sep 19
> > > > 08:30 naming-factory.jar -rw-r--r--    1 root     root        37601
> > > > Sep 19 08:30
> > > > naming-resources.jar -rw-r--r--    1 root     root        80054 Sep
> > > > 19 08:30 servlet.jar
> > > >
> > > >Here is my code sniplet ...
> > > >
> > > >    Connection conn = null;
> > > >    Statement stmt = null;
> > > >    ResultSet rset = null;
> > > >
> > > >    Context ctx = new InitialContext();
> > > >    if(ctx == null )
> > > >    {
> > > >      throw new Exception("Boom - No Context");
> > > >    }
> > > >
> > > >    DataSource ds = (DataSource)ctx.lookup( "java:comp/env/jdbc/JKW");
> > > >
> > > >    try
> > > >    {
> > > >      conn = ds.getConnection();
> > > >      stmt = conn.createStatement();
> > > >
> > > >And the error message ...
> > > >
> > > >java.sql.SQLException: Cannot load JDBC driver class 'null'
> > > >        at
> > > >org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSour
> > > >ce.j ava:529) at
> > > >org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.
> > > >java
> > > >
> > > >:312) at jkw.jsp.beans.SkillTypeBean.setTypeId(SkillTypeBean.java:42)
> > > >: at
> > > >
> > > > sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
> > > >sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.j
> > > >ava: 39) at
> > > >sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccess
> > > >orIm pl.java:25)
> > > >
> > > >
> > > >Any ideas?
> > > >
> > > >Thanks,
> > > >John
> >
> >--
> >John Walstra
> >1002 North Stanford Street
> >Port Washington, WI 53074
> >H: (262) 284-2395
> >C: (847) 858-2395
> >
> >jwalstra@spoonserver.com
> >john_walstra@yahoo.com
> >jwalstra@wi.rr.com
> >
> >It is so stupid of modern civilisation to have given up believing in the
> >devil when he is the only explanation of it.
> >                 -- Ronald Knox, "Let Dons Delight"
> >
> >--
> >To unsubscribe, e-mail:  
> > <mailto:tomcat-user-unsubscribe@jakarta.apache.org> For additional
> > commands, e-mail: <mailto:tomcat-user-help@jakarta.apache.org>

-- 
John Walstra
1002 North Stanford Street
Port Washington, WI 53074
H: (262) 284-2395
C: (847) 858-2395

jwalstra@spoonserver.com
john_walstra@yahoo.com
jwalstra@wi.rr.com

The unfacts, did we have them, are too imprecisely few to warrant our 
certitude.

--
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