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/**
* Copyright (c) 2002 by Phil Hanna
* All rights reserved.
*
* You may study, use, modify, and distribute this
* software for any purpose provided that this
* copyright notice appears in all copies.
*
* This software is provided without warranty
* either expressed or implied.
*/
package com.jspcr.servlets;
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
/**
* An example of a JSP superclass that can be selected with
* the <code>extends</code> attribute of the page
* directive. This servlet automatically loads the
* JDBC-ODBC driver class when initialized and establishes
* a connection to the USDA nutrient database.
*/
public abstract class NutrientDatabaseServlet
extends HttpServlet
implements HttpJspPage
{
protected Connection con;
/**
* Initialize a servlet with the driver
* class already loaded and the database
* connection established.
*/
public void init(ServletConfig config)
throws ServletException
{
super.init(config);
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://localhost/usda15");
}
catch (Exception e) {
throw new UnavailableException(e.getMessage());
}
jspInit();
}
/**
* Closes the database connection when
* the servlet is unloaded.
*/
public void destroy()
{
try {
if (con != null) {
con.close();
con = null;
}
}
catch (Exception ignore) {}
jspDestroy();
super.destroy();
}
/**
* Called when the JSP is loaded.
* By default does nothing.
*/
public void jspInit() {}
/**
* Called when the JSP is unloaded.
* By default does nothing.
*/
public void jspDestroy() {}
/**
* Invokes the JSP's _jspService method.
*/
public final void service(
HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
_jspService(request, response);
}
/**
* Handles a service request.
*/
public abstract void _jspService(
HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException;
}
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Download: ConnectToDatabaseInServlet.zip( 4 k)