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Tomcat Datasource configuration using MySQL

Configuring a MySQL Datasource on Tomcat 

Pre-requisite. Download MySQL JDBC Driver from: https://dev.mysql.com/downloads/connector/j/

In order to configure a Datasource on Tomcat for MySQL Database you need to follow these three simple steps:

1) Define the Datasource in server.xml
Include a Datasource configuration in your Tomcat's server.xml file within the Context section, containing information about the JDBC URL, username and password and the maximum number of active connections allowed in the pool:

<Resource name="jdbc/MySQLDS" auth="Container" type="javax.sql.DataSource"
         username="root"
         password="admin"
         driverClassName="com.mysql.jdbc.Driver"
         url="jdbc:mysql://localhost:3306/schema"
         maxActive="15"
         maxIdle="7"
         defaultTransactionIsolation="READ_COMMITTED"
         validationQuery="Select 1" />


2) Install JDBC Driver 
Next, before starting up Tomcat place MySQL JDBC driver (e.g. mysql-connector-java-5.1.29-bin.jar) into CATALINA_HOME/lib/

3) Add a reference to the DataSource in web.xml 
Finally, in your web.xml reference your datasource by including the JNDI name assigned in your server.xml:

<resource-ref>
 <description>Oracle Datasource for tomcat </description>
 <res-ref-name>jdbc/MySQLDS</res-ref-name>
 <res-type>javax.sql.DataSource</res-type>
 <res-auth>Container</res-auth>
</resource-ref>

Now you can look up your Datasource in your application as follows:
 
InitialContext cxt = new InitialContext();
 

DataSource ds = (DataSource) cxt.lookup( "java:/comp/env/jdbc/MySQLDS" );

if ( ds == null ) {
   throw new Exception("Data source not found!");
}
 

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