Convert the following C++ Code  into Java Object-Oriented Programming:

#include <iostream>
using namespace std;
int main() 
{
  int menu, bill, quantity, soda, burger, chicken, pasta;

  std:: cout << " Please select your order. \n"; 
  cout << " Main Menu \n";
  std:: cout << " Soda press 1 \n Burger press 2 \n Chicken press 3 \n Pasta press 4 \n\n";
  cout << " Enter code from main menu:";
  std:: cin >> menu;

  if ((menu <=0) || (menu >=5))
  {
    std:: cout<< "Invalid code! Please check the menu again.";
  }

  else if (menu == 1)
  {
    std:: cout << " Please select : Soda \n";
    std:: cout << " Coke: P25 press 1 \n Pepsi: P28 press 2 \n RC: P26 press 3 \n\n";
    std:: cout << " Enter code from soda menu: ";
    std:: cin >> soda;{
    if ((soda <=0) || (soda >=4))
  {
    std:: cout<< "Invalid code! Please check the menu again.";
  }
    else {
    std:: cout <<"\n Please enter number of order: ";
    std:: cin >> quantity;
      }
    }
    if (soda == 1)
    {
      bill = quantity*25;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
    else if (soda == 2)
   {
      bill = quantity*28;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
     else if (soda == 3)
   {
      bill = quantity*26;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
  
  }
    else if (menu == 2)
  {
    std:: cout << " Please select : Burger \n";
    std:: cout << " Regular Burger: P25 press 1 \n Cheese Burger: P35 press 2 \n Ham & egg Burger: P50 press 3 \n\n";
    std:: cout << " Enter code from Burger menu: ";
    std:: cin >> burger;{
    if ((burger <=0) || (burger >=4))
  {
    std:: cout<< "Invalid code! Please check the menu again.";
  }
    else {
    std:: cout <<"\n Please enter number of order: ";
    std:: cin >> quantity;
      }
    }
    if (burger == 1)
    {
      bill = quantity*25;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
    else if (burger == 2)
   {
      bill = quantity*35;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
     else if (burger == 3)
   {
      bill = quantity*50;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
  }
      else if (menu == 3)
  {
    std:: cout << " Please select : Chicken \n";
    std:: cout << " Crispy fried chicken: P60 press 1 \n Chicken BBQ: P75 press 2 \n Buttered Chicken: P85 press 3 \n\n";
    std:: cout << " Enter code from Chicken menu: ";
    std:: cin >> chicken;
  {
    if ((chicken <=0) || (chicken >=4))
  {
    std:: cout<< "Invalid code! Please check the menu again.";
  }
    else {
    std:: cout <<"\n Please enter number of order: ";
    std:: cin >> quantity;
      }
    }
    if (chicken == 1)
    {
      bill = quantity*60;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
    else if (chicken == 2)
   {
      bill = quantity*75;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
     else if (chicken == 3)
   {
      bill = quantity*85;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
  }
      else if (menu == 4)
  {
    std:: cout << " Please select : Pasta \n";
    std:: cout << " Italian Pasta: P120 press 1 \n Cream cheese Pasta: P160 press 2 \n Pesto Pasta: P175 press 3 \n\n";
    std:: cout << " Enter code from Pasta menu: ";
    std:: cin >> pasta;{
    if ((pasta <=0) || (pasta >=4))
  {
    std:: cout<< "Invalid code! Please check the menu again.";
  }
    else {
    std:: cout <<"\n Please enter number of order: ";
    std:: cin >> quantity;
      }
    }
    if (pasta == 1)
    {
      bill = quantity*120;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
    else if (pasta == 2)
   {
      bill = quantity*160;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
     else if (pasta == 3)
   {
      bill = quantity*175;
      std:: cout << " Your bill is " << bill;
      std:: cout << "\n Please pay at the counter. Thank you & come again!";
    }
  }
  return 0;
  }