CODEWITHSUNDEEP
javajspservlets
sheetal
sheetal

Reputation: 199

How to compare the elements inside map with another element?

I am trying a simple login page using JSP form and Displaying HomePage through a servlet.I am storing a couple of username and passwords inside a hashmap.I would like to compare the username and password entered by the user with those existing inside the hashmap and display an error message if username or password is wrong.How can I achieve this? TIA

Login.jsp

  <%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
  <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
  <html>
  <head>
  <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
  <title>Login</title>
  </head>
  <body>
  <center>
  <b>LOGIN PAGE</b><br>
  </center>
  <form name="login" method="post" action="Servlet1">
  <center>
  USER NAME: <input type="text" name="username"> 
  <br>
  <br>
  PASSWORD: <input type="password"> 
  <br>
  <br> 
  <input type="submit" value="LOGIN">
  </center>
  </form>
  </body>

Servlet1.java

  public class Servlet1 extends HttpServlet{

  public void doPost(HttpServletRequest request,HttpServletResponse response)
throws IOException{

    String username;
    String password;
    String uname;
    String pwd;

    username = request.getParameter("username");
    password = request.getParameter("password");
    PrintWriter out = response.getWriter();

    Map<String,String>users = new HashMap<String,String>();
    users.put("Sheetal", "sss");
    users.put("Raj","rrr");

    }
    }

Upvotes: 2

Views: 192

Answers (5)

Sandesh
Sandesh

Reputation: 37

public boolean checkAccess(Map<String, String> users, String username,String password) {
    boolean retunValue = Boolean.FALSE;
    if (users != null && users.size() > 0 && !username.isEmpty()
            && !password.isEmpty()) {
        if (users.get(username) != null) {
            if (password.equals(users.get(username)))
                retunValue = true;
        }
    }
    return retunValue;
}

Upvotes: 0

TSKSwamy
TSKSwamy

Reputation: 225

public class Servlet1 extends HttpServlet{    

        final Map<String, String> users = new HashMap<>();

        @Override
        public void init() throws ServletException {
            // user name as key and it is unique for every user. password as value.
            users.put("user1", "pwd1"); 
            users.put("user2", "pwd2");
            users.put("user3", "pwd3");
            users.put("user4", "pwd4");
            users.put("user5", "pwd5");
        }


         @Override
            public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
            {
                String strUserName = request.getParameter("user1"); 
                String strPassword = request.getParameter("pwd1");

                String userpassword = users.get(strUserName);
                if (userpassword != null
                        && userpassword.equals(strPassword)) {
                        // login success
                } else {
                        // invalid user
                }

            }
      }

Upvotes: 0

Journeycorner
Journeycorner

Reputation: 2542

import java.util.HashMap;
import java.util.Map;

class Main {

    public static void main(String args[]) {
            Map<String, String> credentials = new HashMap<String, String>();
            credentials.put("user", "correctpass");

            String inputUsername = "user";
            String inputPassword = "correctpass";

            String passOnMap = credentials.get(inputUsername);
            if (passOnMap != null
                    && passOnMap.equals(inputPassword)) {
                    // correct login
            } else {
                    // wrong user/passw
            }
    }
}

Upvotes: 1

Tkachuk_Evgen
Tkachuk_Evgen

Reputation: 1354

public boolean checkAccess(String username,String password){
   return password.equals(users.get(username));
}

Upvotes: 3

gknicker
gknicker

Reputation: 5569

Retrieve the user's password from the map and check it against the supplied password.

boolean valid = password.equals(users.get(username));

Upvotes: 2

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