Recipe 21.2: Configuring a DataSource in Tomcat You want to
configure a javax.sql.DataSource for use in a servlet with the
Tomcat web container. resource element in Tomcat's server.xml
file and an associated resource-ref element in the web.xml
deployment descriptor. Tomcat makes it easy to set up a
connection pool so that servlets and JSPs can efficiently share
database connections. In web sites that have many simultaneous
users, a connection pool improves efficiency by sharing existing
database connections, rather than creating a new connection and
tearing it down every time an application has to use the
database. Another benefit of configuring a connection pool is
that you can change the database system that a servlet or JSP is
using without touching the Java code, because the database
resource is configured outside of the servlet or JSP. Here are
the steps for configuring a DataSource with Tomcat:
ResourceParamselement in server.xml, or in the XML file that you
have placed in Tomcat's webapps directory. Th