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Basic Authentication Program in Java

Check username and password against hardcoded values.

BeginnerModule 2: Conditional ProgramsExample 20 of 20

basic-authentication-program.java

1import java.util.Scanner;
2
3public class Main {
4    public static void main(String[] args) {
5        final String USERNAME = "admin";
6        final String PASSWORD = "1234";
7
8        Scanner sc = new Scanner(System.in);
9
10        System.out.print("Enter username: ");
11        String user = sc.nextLine();
12        System.out.print("Enter password: ");
13        String pass = sc.nextLine();
14
15        if (USERNAME.equals(user) && PASSWORD.equals(pass)) {
16            System.out.println("Login Successful");
17        } else {
18            System.out.println("Invalid Credentials");
19        }
20
21        sc.close();
22    }
23}

Output

Enter username: admin
Enter password: 1234
Login Successful

What's going on

Use equals(), not ==. == compares references. Two equal-looking strings from Scanner are still different objects.

Hardcoded admin/1234 is a demo. Do not ship it. Scanner does not hide the password.

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