Creating a database connection pool

Question

Need information on creating a connection pool to the database (irrespective of the database) , and how efficient they are? What are the conditions where they can enhance pe

Answer 1

Creating database connection pool using tomcat

1. Tomcat enter resource inside : conf/context.xml

Put the resource entries in context.xml file:

---

2. create a class which will create the connection pool

public class MyConnectionFactory {
    private static String module = "[ QuoteConnectionFactory ]";
    private static QuoteConnectionFactory connectionFactory;

    protected QuoteConnectionFactory() {
    }

    /**
     *
     * @return=>getInstance() is a static method which will return the instance
     *                        of its own class
     */
    public static QuoteConnectionFactory getInstance() {
        if (connectionFactory == null)
            connectionFactory = new QuoteConnectionFactory();
        return connectionFactory;
    }

    /**
     *
     * @param jndiName

     */
    public Connection getConnection(String jndiName) {
        System.out.println("jndiName=======" + jndiName);
        Connection conn = null;
        InitialContext cxt = null;
        DataSource dataSource = null;
        try {
            cxt = new InitialContext();
            Context envContext  = (Context)cxt.lookup("java:/comp/env");
            dataSource = (DataSource)envContext.lookup(jndiName);
        } catch (NamingException e) {

        } catch (Exception e) {

        }

        if (dataSource == null) {

            try {
                conn = dataSource.getConnection();
            } catch (Exception e) {

            }

            System.out.println("connection===================" + conn);
            return conn;
        }
    }

3. edit web.xml file

    DB Connection
    jdbc/jndiName
    javax.sql.DataSource
    Container

4. Use in code

Connection con= QuoteConnectionFactory.getInstance(). getConnection("jndiName");