OneCompiler

ja19

178
  1. Write a java program to accept ‘N’ Integers from a user store them into LinkedList
    Collection and display only negative integers. [15 M]

import java.util.LinkedList;
import java.util.Scanner;

public class NegativeIntegersLinkedList {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter the number of integers (N): ");
int n = scanner.nextInt();

    LinkedList<Integer> integers = new LinkedList<>();

    System.out.println("Enter " + n + " integers:");
    for (int i = 0; i < n; i++) {
        int num = scanner.nextInt();
        integers.add(num);
    }

    System.out.println("Negative integers:");
    for (int num : integers) {
        if (num < 0) {
            System.out.println(num);
        }
    }

    scanner.close();
}

}

  1. Write a SERVLET application to accept username and password, search them into
    database, if found then display appropriate message on the browser otherwise display
    error message

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();

    String username = request.getParameter("username");
    String password = request.getParameter("password");

    
    boolean isValidUser = checkCredentials(username, password);

    if (isValidUser) {
        out.println("<html>");
        out.println("<head>");
        out.println("<title>Login Status</title>");
        out.println("</head>");
        out.println("<body>");
        out.println("<h2>Login Successful!</h2>");
        out.println("</body>");
        out.println("</html>");
    } else {
        out.println("<html>");
        out.println("<head>");
        out.println("<title>Login Status</title>");
        out.println("</head>");
        out.println("<body>");
        out.println("<h2>Error: Invalid username or password!</h2>");
        out.println("</body>");
        out.println("</html>");
    }

    out.close();
}

 (replace with actual database query)
private boolean checkCredentials(String username, String password) {
    
    return username.equals("admin") && password.equals("admin123");
}

}