sql2java and struts

[Hamvil]

Hi,

I'm using sql2java in several webapp.

So far I use a custom Request Processor in order to init the DB connection.

Basically I have something like this:

        try {

            Context initCtx = new InitialContext();

            DataSource dataSource = (DataSource) initCtx.lookup("java:comp/env/jdbc/cocus");
            Manager.getInstance().setDataSource(dataSource);

        } catch (Exception e) {

            logger.error("Exception initializing datasource", e);

            return false;

        }

I suspect that this is not a good way to do the connection (basically this code is called each time
a request is made from the client. Is there a better way to do this?

Thanks for any help
R.

[Alain Fagot Béarez]

The classical solution in webapps (with or without Struts) is to use a Filter.  It is guaranteed to be initialized exactly once by the container, with the following configuration in the web.xml deployment descriptor:

<web-app id="WebApp_ID">
    <filter>
        <filter-name>Sql2JavaFilter</filter-name>
        <display-name>Sql2JavaFilter</display-name>
        <filter-class>net.sourceforge.sql2java.Filtro</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>Sql2JavaFilter</filter-name>
        <url-pattern>*.do</url-pattern>
    </filter-mapping>
    <servlet>
        <servlet-name>action</servlet-name>
...

and with the following code for the filter class:

package net.sourceforge.sql2java;

import java.io.IOException;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.sql.DataSource;

import org.acme.sample.Manager;

public class Filtro implements Filter {
    public void init(FilterConfig filterConfig) throws ServletException {
        try {
            Context initCtx = new InitialContext();
            DataSource dataSource = (DataSource) initCtx.lookup("java:comp/env/jdbc/cocus");
            Manager.getInstance().setDataSource(dataSource);
        } catch (NamingException ne) {
            filterConfig.getServletContext().log("Exception initializing datasource", ne);
        }
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
            ServletException {
        // nothing specific to do here, just pass on
        chain.doFilter(request, response);
    }

    public void destroy() {
    }
}

[Hamvil]

Thanks!

It worked fine.