import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
import java.security.*;
public class RateChangeServlet extends HttpServlet {
private Connection dbConnection;
public void init() {
dbConnection = DBInfo.connectToDatabase();
}
public void destroy() {
if(dbConnection != null) {
try {
dbConnection.close();
}
catch(Exception e) { }
}
}
private boolean updateActivity(String activity, double newRate)
{
try {
Statement stmt = dbConnection.createStatement ();
String insertcommand =
"update rates set rate = " +
newRate +
" where activity='" + activity + "'";
stmt.executeUpdate(insertcommand);
stmt.close();
}
catch(Exception e) { return false; }
return true;
}
private boolean addActivity(String activity, double rate)
{
try {
Statement stmt = dbConnection.createStatement ();
String insertcommand =
"insert into rates values (";
insertcommand = insertcommand + "'" + activity + "', ";
insertcommand = insertcommand + rate + ")";
stmt.executeUpdate(insertcommand);
stmt.close();
}
catch(Exception e) { return false; }
return true;
}
public void doPost (HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
String activity = request.getParameter("Activity");
String rate = request.getParameter("Rate");
if((activity==null) || (rate==null)) {
response.sendRedirect("/combo/BadData.html");
return;
}
double drate = 0.0;
try {
drate = Double.parseDouble(rate);
}
catch(Exception e) {
response.sendRedirect("/combo/BadData.html");
return;
}
ServletContext ctx = getServletContext();
RatesRecord rates = (RatesRecord)
ctx.getAttribute("RatesTable");
if(rates==null) {
rates = new RatesRecord();
ctx.setAttribute("RatesTable", rates);
}
double dcurrent = rates.getRate(activity);
boolean ok = true;
if(dcurrent==0.0)
ok = addActivity(activity, drate);
else
if(dcurrent != drate)
ok = updateActivity(activity, drate);
ctx.removeAttribute("RatesTable");
if(!ok) {
response.sendRedirect("/combo/NoDB.html");
return;
}
PrintWriter out = response.getWriter();
out.println("Change recorded");
out.println("");
out.println("Update performed
");
out.println("The table of hourly pay rates has been updated");
out.println("");
}
public void doGet (HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
PrintWriter out = response.getWriter();
out.println("
Change hourly rate" );
out.println("" );
out.println("");
}
}