package forms;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
* A login servlet
*
* @version 1.0 2001/08/15
* @author Mike Gehard
*/
public class Login extends HttpServlet{
/** Used to hole the username/password combinations */
protected Map users = new HashMap();
/** Constant for the username field*/
public static String USERNAME = "username";
/** Constant for the passowrd field*/
public static String PASSWORD = "password";
/**
* Initializaion method. Sets up username/password combinations
*/
public void init(){
// user names and passwords
users.put("Mike Gehard", "se452");
users.put("Scott McNealy", "java");
users.put("Bill Gates", "windows");
users.put("Larry Ellison", "oracle");
}
/**
* Handle POST request.
* 1) Gets information from form
* 2) Validates login data
* 3) Displays results of validation
*
* @param request the HTTPServletRequest associated with this servlet
* @param response the HTTPServletResponse associated with this servlet
* @throws ServletException
* @throws IOException
*
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException{
// get the form data
String userName = request.getParameter(USERNAME);
String password = request.getParameter(PASSWORD);
//prep the data
if (userName != null){
userName = userName.trim();
}
if (password != null){
password = password.trim();
}
// look up login/password combiniation
if (userName != null && userName.length() > 0){
if (password != null && password.length() > 0){
String pw = (String) users.get(userName);
if (pw != null){ //you found the login
if (pw.equals(password)){ // check the password
// get the first name of the user
String firstName = userName;
// look for a space
int i = userName.indexOf(' ');
if (i > 0){
firstName = userName.substring(0, i);
}
sendPage(response, "Login successful", "Hello " + firstName + "!");
}
else { // you didn't match the password
sendPage(response, "Login fail", "Sorry, incorrect password");
}
}
else {
sendPage(response, "Login fail", "Sorry, not a user");
}
}
else {
sendPage(response, "Login fail", "Sorry, no password");
}
}
else {
sendPage(response, "Login fail", "Sorry, no username");
}
}
/**
* Handle GET request.
* Delagates to doPost().
*
* @param request the HTTPServletRequest associated with this servlet
* @param response the HTTPServletResponse associated with this servlet
* @throws ServletException
* @throws IOException
*
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException{
// forward to doPost()
doPost(request, response);
}
/**
* Handle generation of the response page sent to the user based on passed
* parameters.
*
* @param response the HTTPServletResponse associated with this servlet
* @param title the title for the generated page
* @param message the message to be displayed on the page
* @throws IOException
*
*/
protected void sendPage(HttpServletResponse response, String title, String message)
throws IOException{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("");
if (title != null) {
out.println(" " + title + "");
}
out.println("");
if (message != null) {
out.println("" + message + "
");
}
out.println("");
out.println("");
}
}