Re: Tomcat - PostgreSQL - Cannot load JDBC driver class "null"

You've probably checked this, but on the offchance you haven't, are you
explicitly pointing to the postgres jdbc jar file in your classpath?
eg
CLASSPATH=$CLASSPATH:.:...whatever...:/usr/local/Tomcat/common/lib/pg73jdbc3.jar

Ron

CRAIG GOLBY wrote:

> Help, I am tearing my hair out.
>
> I am a newbie to Linux and Tomcat, and am therefore amazed that I have
> got as far as I have, that said I now seem to be stuck in front of a
> brick wall, with no ladder !!
>
> Tomcat 4.1.24 is running on ServerOne (Red Hat 9), it is currently
> serving out a couple of very basic JSP's and seems to be working quite
> well. ServerOne also has J2SDK 1.4.1_03 installed. PostgreSQL 7.3 is
> running on ServerTwo (Red Hat 9). Have also installed pgAdminIII on
> both a Windows Laptop and ServerTwo. The Laptop version works fine,
> if a little unstable, so TCP/IP connectivity is working fine.
>
> Within PostgreSQL I have created a new Db called "PersonalDb", within
> the public Schema I have created a table called "testOne". TestOne
> has three columns, Id, FieldOne and DateStamp, and there are currently
> 2 rows of data within the table
>
> Sample of code used is below, along with a list of the Jar files in
> common/lib.
>
> I have read through so many mailing lists now and tried so many things
> that I dont know what I have and havent done, am fairly sure that it
> is either a configuration issue or a missing file so will no doubt
> kick myself when I find out the answer.
>
> Any assistance would be greatly appreciated.
>
> Regards
>
>
> Craig
>
>
> *******************************************************
> Server XML :- Tomcat/conf
> *******************************************************
> <Context path="/DBTest"
> docBase="DBTest"
> debug="5"
> reloadable="true"
> crossContext="true">
>
> <Logger className="org.apache.catalina.logger.FileLogger"
> prefix="localhost_DBTest_log." suffix=".txt"
> timestamp="true"/>
>
> <Resource name="jdbc/PersonalDb"
> type="javax.sql.DataSource"
> auth="Container"/>
>
> <ResourceParams name="jdbc/PersonalDb">
> <parameter>
> <name>factory</name>
> <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
> </parameter>
>
> <parameter>
> <name>driverClassName</name>
> <value>org.postgresql.Driver</value>
> </parameter>
>
> <parameter>
> <name>url</name>
> <value>jdbc:postgresql://ServerTwo:5432/PersonalDb</value>
> </parameter>
>
> <parameter>
> <name>username</name>
> <value>myUser</value>
> </parameter>
>
> <parameter>
> <name>password</name>
> <value>myPassword</value>
> </parameter>
>
> <parameter>
> <name>maxActive</name>
> <value>10</value>
> </parameter>
>
> <parameter>
> <name>maxIdle</name>
> <value>30</value>
> </parameter>
>
> <parameter>
> <name>maxWait</name>
> <value>10000</value>
> </parameter>
>
> </ResourceParams>
> </Context>
>
> </Host>
> </Engine>
> </Service>
>
>
> *******************************************************
> Web XML :- Tomcat/webapps/root/WEB-INF
> *******************************************************
> <description>PostgreSQL Test App</description>
> <resource-ref>
> <description>postgreSQL Datasource example</description>
> <res-ref-name>jdbc/PersonalDb</res-ref-name>
> <res-type>javax.sql.DataSource</res-type>
> <res-auth>Container</res-auth>
> </resource-ref>
>
>
> *******************************************************
> My Class File
> *******************************************************
>
> public void init() {
> try{
> Context ctx = new InitialContext();
> if(ctx == null )
> throw new Exception("Boom - No Context");
> status = "checking CTX";
>
> DataSource ds =
> (DataSource)ctx.lookup("java:comp/env/jdbc/PersonalDb");
> status = "Completing Lookup of CTX";
>
> if (ds != null)
> {
> status = "Creating Connection";
> Connection conn = ds.getConnection(); <----- FAILS HERE
> status = "Created Connection";
> if(conn != null)
> {
> foo = "Got Connection "+conn.toString();
> Statement stmt = conn.createStatement();
> ResultSet rst =
> stmt.executeQuery(
> "select Id, FieldOne, DateStamp from Public.testOne");
> status = "Completing Select";
> if(rst.next())
> {
> foo=rst.getString(2);
> bar=rst.getInt(3);
> }
> status = "Looped through Resultset";
> conn.close();
> }
> }
> else {status = "Fell into Else";}
> }catch(Exception e) {
> e.printStackTrace();
> status = status + ", now in exception block :-" + e.toString();
>
> }
> }
> *******************************************************
> Class Files in Tomcat/common/lib
> *******************************************************
> activation.jar
> ant.jar
> collections-2.1.jar
> commons-collections.jar
> commons-dbcp-1.0.jar
> commons-dbcp.jar
> commons-logging-api.jar
> commons-pool.jar
> jasper-compiler.jar
> jasper-runtime.jar
> jdbc2_0-stdext.jar
> jndi.jar
> jta.jar
> mail.jar
> naming-common.jar
> naming-factory.jar
> naming-resources.jar
> pg73jdbc3.jar
> pool-1.0.1.jar
> postgresql.jar (Copy of pg73jdbc3.jar)
> servlet.jar
>
>
>
>
>