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    <p>It is probably not a good solution that you are having here. When you are using servlets in order to do something your application loads, you can have listeners. What you have to do is, first create a class implementing <a href="http://docs.oracle.com/javaee/5/api/javax/servlet/ServletContextListener.html" rel="nofollow">ServletContextListener</a>.</p> <pre><code>public class ContextListener implements ServletContextListener { public void contextInitialized(ServletContextEvent sce) { ServletContext context=sce.getServletContext(); String dburl=context.getInitParameter("dbUrl"); String dbusername=context.getInitParameter("dbUserName"); String dbpassword=context.getInitParameter("dbPassword"); DBConnector.createConnection(dburl, dbusername, dbpassword); System.out.println("Connection Establised........."); } public void contextDestroyed(ServletContextEvent sce) { DBConnector.closeConnection(); } } </code></pre> <p>After that you can create another class to create the connection when application loads.</p> <pre><code>public class DBConnector { private static Connection con; public static void createConnection(String dbUrl,String dbusername,String dbPassword){ try { Class.forName("org.postgresql.Driver"); con=DriverManager.getConnection(dbUrl, dbusername, dbPassword); } catch (Exception ex) { ex.printStackTrace(); } } public static Connection getConnection(){ return con; } public static void closeConnection(){ if(con!=null){ try { con.close(); } catch (SQLException ex) { ex.printStackTrace(); } } } } </code></pre> <p>Then when ever you want to get the db connection you can call the static getConnection method and get it. In order to call your listener class you have to add the listener tags inside the web.xml.</p> <pre><code>&lt;context-param&gt; &lt;param-name&gt;dbUrl&lt;/param-name&gt; &lt;param-value&gt;jdbc:postgresql://localhost:5432/jbossdb&lt;/param-value&gt; &lt;/context-param&gt; &lt;context-param&gt; &lt;param-name&gt;dbUserName&lt;/param-name&gt; &lt;param-value&gt;qwerty&lt;/param-value&gt; &lt;/context-param&gt; &lt;context-param&gt; &lt;param-name&gt;dbPassword&lt;/param-name&gt; &lt;param-value&gt;qwerty&lt;/param-value&gt; &lt;/context-param&gt; &lt;listener&gt; &lt;listener-class&gt;com.icbt.bookstore.listener.ContextListener&lt;/listener-class&gt; &lt;/listener&gt; </code></pre> <p>It is not good practice to hardcode your db usernames and passwords. Instead you can use servlet init parameters in the web.xml as shown.</p> <p>Hope, this answers your question.</p>
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    1. POinitializing a database connection object once and reusing it - jboss
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    1. USKrishan
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      1. VTUpMod
    1. COvery good answer! I did not know that these could be done. Can you give me a link where I can learn more about what all can be put into web.xml file. one more question - pls see my comment to Jaydee's answer
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      1. USAshwin
    2. COhttp://shop.oreilly.com/product/9780596516680.do this is a good book that you can learn about servlets and jsps. If you want to learn about web.xml tags read http://docs.oracle.com/cd/E13222_01/wls/docs81/webapp/web_xml.html
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      1. USKrishan
    3. COthat depends on the size of your application. If you have a lot of database operations then you will have to use database connection pooling as @Jaydee has explained.
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