Urgent : Error connecting to mysql Database from JSP page deployed on tomcat server

[Jayanta Halder <JH...@dfg.ca.gov>]

Hi,
 
I have installed tomcat on HP-UX box.I have deployed my web application
on tomcat container.I have copied mysql JDBC driver under common/lib
area.
 
While running the application i am getting following error ....
 
Cannot load JDBC driver class 'null'
java.lang.NullPointerException:
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Unknown Source)
        at
org.apache.commons.dbcp.BasicDataSource.createDataSource(Unknown
Source)
        at
org.apache.commons.dbcp.BasicDataSource.getConnection(Unknown Source)
        at org.apache.jsp.index_0005fmysql$jsp._jspService(Unknown
Source)
        at org.apache.jasper.runtime.HttpJspBase.service(Unknown
Source)
        at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at org.apache.jasper.servlet.JspServletWrapper.service(Unknown
Source)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(Unknown
Source)
        at org.apache.jasper.servlet.JspServlet.service(Unknown
Source)
        at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown
Source)
        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown
Source)
        at org.apache.catalina.core.StandardWrapperValve.invoke(Unknown
Source)
        at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(Unkno
wn Source)
        at org.apache.catalina.core.StandardPipeline.invoke(Unknown
Source)
        at org.apache.catalina.core.ContainerBase.invoke(Unknown
Source)
        at org.apache.catalina.core.StandardContextValve.invoke(Unknown
Source)
        at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(Unkno
wn Source)
        at org.apache.catalina.core.StandardPipeline.invoke(Unknown
Source)
        at org.apache.catalina.core.ContainerBase.invoke(Unknown
Source)
        at org.apache.catalina.core.StandardContext.invoke(Unknown
Source)
        at org.apache.catalina.core.StandardHostValve.invoke(Unknown
Source)

 
Can u please tell me what is wrong ?

Thanks,

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RE: Urgent : Error connecting to mysql Database from JSP pagedeployed on tomcat server

[Catherine Shepherd <ca...@imperiumglobal.com>]

Firstly perhaps this is a question for a Java forum.  However, it seems you
are not instantiating your driver properly.  This is a connection test class
that works fine connecting from a Tomcat instance on Win2K to a MySQL
instance on a remote Red Hat 7.2 box using the MM.MySQL driver
(http://mmmysql.sourceforge.net/).  Try it out on your system.  If you are
using a different driver you'll need to change the DBDRIVER String.

package com.imperiumglobal.tools.db;
import java.sql.*;
public class ConnectionTester {
  public static void main(String[] args) {
    String DBDRIVER = "org.gjt.mm.mysql.Driver";
    String DBURL = "jdbc:mysql://[hostname]/[dbname]";
    String DBUSER = "[username]";
    String DBPASSWORD = "[db password]";
    System.out.println("trying connection...");
    try {
      Class.forName(DBDRIVER).newInstance();
      Connection conn =
        DriverManager.getConnection(
          DBURL + "?user=" + DBUSER + "&password=" + DBPASSWORD);
      System.out.println("good connection");
    } catch (Exception e) {
      System.out.println("no connection: " + e);
    }
  }
}

James

-----Original Message-----
From: Jayanta Halder [mailto:JHALDER@dfg.ca.gov]
Sent: 14 June 2002 16:35
To: tomcat-user@jakarta.apache.org
Subject: Urgent : Error connecting to mysql Database from JSP
pagedeployed on tomcat server

While running the application i am getting following error ....

Cannot load JDBC driver class 'null'
java.lang.NullPointerException:



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