conf/web.xml

<resource-ref>
<description>DB Connection</description>
<res-ref-name>jdbc/login</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>

conf/context.xml

<Context crossContext="true" debug="0" docBase="login" path="/login" reloadable="false">
<Resource name="jdbc/login" type="javax.sql.DataSource" />
<ResourceParams name="jdbc/login">
<parameter>
<name>maxActive</name>
<value>20</value>
</parameter>
<parameter>
<name>maxIdle</name>
<value>10</value>
</parameter>
<parameter>
<name>maxWait</name>
<value>10000</value>
</parameter>
<parameter>
<name>username</name>
<value>daniele</value>
</parameter>
<parameter>
<name>password</name>
<value>daniele</value>
</parameter>
<parameter>
<name>driverClass</name>
<value>com.mysql.jdbc.Driver</value>
</parameter>
<parameter>
<name>url</name>
<value>jdbc:mysql://localhost:3306/test</value>
</parameter>
<parameter>
<name>removeAbandoned</name>
<value>true</value>
</parameter>
<parameter>
<name>removeAbandonedTimeout</name>
<value>60</value>
</parameter>
<parameter>
<name>logAbandoned</name>
<value>true</value>
</parameter>
</ResourceParams>
</Context>
</Context>

Servlet

javax.naming.Context ctx = new javax.naming.InitialContext();
DataSource ds = (DataSource) ctx.lookup("java:/comp/env/jdbc/login");
Connection con = ds.getConnection();

Ho l'errore:

org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'

dove sbaglio