Java Database Connectivity (JDBC)

Dear all,

I have an issue with creating a connection pool within a web application in order to be used by several servlets. I appreciate if you could kindly give me a hand.

I'm using:

Web server: Apache-tomcat: 6.0.18
Oracle Database 11g Enterprise: 11.1.0.6.0 - Production
Operating system: Linux (ubuntu 8.10)
IDE: Sun Netbeans
Oralce JDBC Drivers: 11.1.0.7.0-Production (ojdbc6.jar and orai18n.jar)
JDK 1.6

Usually, just for creating a connection to my database (without using a connection pool), I proceed in the following way:

String dbURL = "jdbc:oracle:thin:@localhost:1521:database01";
String username = "scott";
String user_password = "tiger";

String userSqlQuery = "SELECT * FROM mytable";

Connection connection = DriverManager.getConnection (dbURL, username, user_password);
Statement statement = connection.createStatement();
statement.executeUpdate(query_text);

This works pretty well allowing to communicate with my oracle database. By this method I have run several projects
with different queries (SELECT, INSERT, UPDATE, DELETE ,etc.) and each time it worked without any problem and
returned the result of the query. Therefore I think that there is no problem with JDBC drivers

However, when I want to create a connection pool, it seems that the lookup method cannot locate Oracle JDBC drivers. That is,

try
{
	InitialContext ic = new InitialContext();
	Context envContext  = (Context)ic.lookup("java:/comp/env");
	dataSource = (DataSource)envContext.lookup("jdbc/oracle11gEnterprise");
       Connection connection = dataSource.getConnection();
}
catch (Exception e)
{
	e.printStackTrace();
}

Just after calling dataSource.getConnection() the java.lang.NullPointerException is thrown.

Any idea?

Thanks in advance,






And for your information, here are context.xml and web.xml files for my project
Here is my context.xml

<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/WebApplication1">
    <Resource name="jdbc/oracle11gEnterprise"
          scope="Shareable"
          type="javax.sql.DataSource"
          auth="Container"
          description="Oracle Database 11g Enterprise"
          maxActive="100"
          maxIdle="30"
          maxWait="10000"
          removeAbandoned="true"
          removeAbandonedTimeout="60"
          logAbandoned="true"
          url="jdbc:oracle:thin:@localhost:1521:database01"
          username="scott"
          password="tiger" />
</Context>

my web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <ConsumeOutput>false</ConsumeOutput>
    <resource-ref>
        <res-ref-name>jdbc/oracle11gEnterprise</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>
    </resource-ref>
    
    <!--
        .
        .  And here as usual I write servlet definition and url mappings
        .
    -->