Jason/web/WEB-INF/web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <resource-ref>
        <description>DB Connection</description>
        <res-ref-name>jdbc/edu </res-ref-name>
        <res-type>javax.sql.DataSource </res-type>
        <res-auth>Container</res-auth>
    </resource-ref>
</web-app>