Cannot create JDBC driver of class '' for connect URL 'null" - HikariCP, Tomcat8, PostgreSQL - postgresql

Question

Firstly I have never setup a JDBC Pool before (So i am sorry if this seems mundane). I have been trying for some time to solve the problem but to no avail. I have explored the suggested options from various other stackoverflow posts but none have been successful.
I have tried:
Including the 'pgjdbc-ng' driver only in the /lib of tomcat and moving the context to the catalina home conf/
Swapping to using the example given by Hikari (but received same error) https://github.com/brettwooldridge/HikariCP/wiki/JNDI-DataSource-Factory-(Tomcat,-etc.)
I am using HikariCP with a PostgreSQL(pgjdbc-ng) driver. Tomcat8 deploys my war file which i build using maven. web.xml, context.xml, java code.
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app>
<display-name>Restful Web Application</display-name>
<resource-ref>
<res-ref-name>jdbc/postgresHikari</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
<servlet>
<servlet-name>Jersey Web Application</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>jersey.config.server.provider.packages</param-name>
<param-value>com.seng402.rest</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Jersey Web Application</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>
</web-app>
context.xml
<?xml version="1.0" encoding="UTF-8"?>
<Context>
<Resource name="jdbc/postgresHikari" auth="Container"
factory="com.zaxxer.hikari.HikariJNDIFactory"
type="javax.sql.DataSource"
minimumIdle="5"
maximumPoolSize="10"
connectionTimeout="300000"
dataSource.implicitCachingEnabled="true"
dataSource.user="docker"
dataSource.password="docker"
jdbcUrl="jdbc:postgresql://192.168.59.103:5432/docker"
driverClassName="com.impossibl.postgres.jdbc.PGDataSource"/>
</Context>
java code
Context initCtx = null;
try {
initCtx = new InitialContext();
Context envCtx;
try {
envCtx = (Context) initCtx.lookup("java:comp/env");
// Look up our data source
DataSource ds = (DataSource) envCtx.lookup("jdbc/postgresHikari");
try {
// Allocate and use a connection from the pool
Connection conn = ds.getConnection(); // throws the error
conn.close();
System.out.println("Connected!");
} catch (SQLException e) {
System.out.println("Failed to Connect!");
e.printStackTrace();
}
} catch (NamingException e) {
System.out.println("Failed to Lookup!");
e.printStackTrace();
}
} catch (NamingException e1) {
System.out.println("Fail to get Context!");
e1.printStackTrace();
}
Output:
Failed to Connect!
java.sql.SQLException: Cannot create JDBC driver of class '' for connect URL 'null'
ds.getConnection() throws the error.
Any suggestions as to how i could fix this or debug further would be greatly appreciated.
SOLVED !!! - context.xml was not being put into the META-INF folder

Answer 1

context.xml was not being put into the META-INF folder

Answer 2

With the JNDI provider, do not use the dataSourceClassName (or dataSource.URL) properties. Use jdbcUrl, and driverClassName if necessary (but try without it first).