InitialContext ctx = new InitialContext();
            DataSource ds = (DataSource) ctx.lookup("java:/comp/env/jdbc/oracledb");
            Connection connection = ds.getConnection();
            connection.setAutoCommit(false);
            return connection;

<resource-ref>
    <res-ref-name>jdbc/oracledb</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
</resource-ref>

<Configure id="wac" class="org.eclipse.jetty.webapp.WebAppContext">
<New id="myds" class="org.eclipse.jetty.plus.jndi.Resource">
    <Arg></Arg>
    <Arg>jdbc/oracledb</Arg>
    <Arg>

         <New class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <Set name="driverClass">oracle.jdbc.OracleDriver</Set>
            <Set name="jdbcUrl">jdbc:oracle:thin:@SRVODA-SCAN.CAIRUNET.AD.BR:1521/WINTP</Set>
            <Set name="user">x</Set>
            <Set name="password">x</Set>
            <Set name="maxPoolSize">20</Set>
            <Set name="minPoolSize">5</Set>
            <Set name="acquireIncrement">5</Set>
            <Set name="maxIdleTime">45</Set>
            <Set name="maxIdleTimeExcessConnections">30</Set>
            <Set name="preferredTestQuery">select sysdate from dual</Set>

        </New>

    </Arg>
</New>

public static boolean closeConnection(Connection connection) {

    if(connection != null) {
        try {
            if(!connection.isClosed()) {
                connection.close();
                return true;
            }else {
                return false;
            }

        } catch (SQLException e) {
            e.printStackTrace();
            throw new IllegalArgumentException(e.getMessage());
        }
    }else {
        return false;
    }
}

<dependency>
        <groupId>com.mchange</groupId>
        <artifactId>c3p0</artifactId>
        <version>0.9.5.2</version>
    </dependency>

    <dependency>
        <groupId>com.mchange</groupId>
        <artifactId>mchange-commons-java</artifactId>
        <version>0.2.7</version>
    </dependency>