Struts DB pooling from 1.0.2 to 1.1

Ranch Hand

Posts: 44

posted 21 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

Hi all,
I'm trying to upgrade an appliction based on the sample web appliction from Wroxs' Beginning JSP Web Development book. This has a database connection pool created by the code below and initiated by Tomcat from the web.xml. From the error (also attached), the pool is not being started. I'm guessing this is due to the use of a GenericDataSource object.
Is these a simple method to fix this? can I replace the GenericDataSOurce with a BasicDataSource object (org.apache.commons.dbcp.BasicDataSource)?
Would you suggest a different method of pooling all together? Ideally, I'd like to retain the ability to use Tomcats built in form authentication.
Any help would be gratefully recieved.
Regards,
Ols

package com.haven.db.util;
import javax.servlet.http.HttpServlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import java.sql.SQLException;
import java.sql.Connection;
import javax.sql.DataSource;
import org.apache.struts.util.GenericDataSource;
//Obtains JDBC driver details from web.xml on startup
public class DBInitServlet extends HttpServlet {
  public void init(ServletConfig config) throws ServletException {
    super.init(config);
    try {
//Creates new instance of GenericDataSource
      GenericDataSource ds = new GenericDataSource();
//Gets properties from initialisation parameters passed from web.xml on startup
      ds.setDriverClass(getInitParameter("driverClass"));
      ds.setUrl(getInitParameter("jdbcURL"));
      ds.setMinCount(Integer.parseInt(getInitParameter("minCount")));
      ds.setMaxCount(Integer.parseInt(getInitParameter("maxCount")));
      ds.setAutoCommit(false);
//Opens connection pool
      ds.open();
//Initialise pool by passing it to the datasource object
      ConnectionPool.init(ds);
    } catch (SQLException e) {
      e.printStackTrace();
      throw new ServletException("Unable to open datasource.");
    }
  }
}

package com.haven.db.util;
import java.sql.SQLException;
import java.sql.Connection;
import javax.sql.DataSource;
//Defines the Connection Pool
public class ConnectionPool {
//Instance of DataSource to handle calls for retrieveing JDBC connections
  private DataSource ds;
//Static singleton instance of ConnectionPool Class
  private static ConnectionPool mySelf;
//Takes instance of DataSource and assigns it an instance variable
  private ConnectionPool(DataSource ds) {
    this.ds = ds;
  }
//Initialises ConnectionPool and passes is the DataSource instance
  public static void init(DataSource ds) {
    mySelf = new ConnectionPool(ds);
  }
//Returns ConnectionPool created above, throws exception if pool is not present
  public static ConnectionPool getInstance() {
    if (mySelf == null) {
      throw new IllegalStateException("Pool not initialized.");
    }
    return mySelf;
  }
//Instance method to retrieve a JDBC connection
  public Connection getConnection() throws SQLException {
    return ds.getConnection();
  }
}