How to Simplify Java Code Input

Question

Hello Everyone, Can anyone know, How can I simplify this code? I check every input for an error, but I think the code is duplicated. I am using this java compiler - https://www.interviewbit.com/online-java-compiler/ Can anyone suggest whats wrong with this code?

long houseNumberOfFloors;
while (true) {
  System.out.print("Enter valid house number of floors: ");
  try {
    houseNumberOfFloors = Long.parseLong(br.readLine());
  } catch (NumberFormatException e) {
    continue;
  }
  if (FlatAttrValidator.checkHouseNumberOfFloors(houseNumberOfFloors)) {
    break;
  }
}

Integer houseNumberOfLifts;
while (true) {
  System.out.print("Enter valid house number of lifts: ");
  try {
    houseNumberOfLifts = Integer.parseInt(br.readLine());
  } catch (NumberFormatException e) {
    continue;
  }
  if (FlatAttrValidator.checkHouseNumberOfLifts(houseNumberOfLifts)) {
    break;
  }
}

Comments

[jimbe]

What is the code for the FlatAttrValidator class?

Answer 1

Is this simple?
I don't know if it works in an online environment.

import java.io.*;

public class Main {
  public static void main(String[] args) throws IOException {
    try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {

      long houseNumberOfFloors = inputAndCheck(br, "Enter valid house number of floors: ",
              Long::parseLong, FlatAttrValidator::checkHouseNumberOfFloors);

      int houseNumberOfLifts = inputAndCheck(br, "Enter valid house number of lifts: ",
              Integer::parseInt, FlatAttrValidator::checkHouseNumberOfLifts);
      
      System.out.println("houseNumberOfFloors=" + houseNumberOfFloors);
      System.out.println("houseNumberOfLifts=" + houseNumberOfLifts);
    }
  }
  
  interface Parser<T> {
    T parse(String s);
  }
  interface Validator<T> {
    boolean validate(T v);
  }
  static <T> T inputAndCheck(BufferedReader br, String prompt, Parser<T> parser, Validator<T> validator) throws IOException {
    while(true) {
      System.out.print(prompt);
      try {
        T v = parser.parse(br.readLine());
        if(validator.validate(v)) return v;
      } catch (NumberFormatException e) {
        //continue;
      }
    }
  }
}

class FlatAttrValidator {
  static boolean checkHouseNumberOfFloors(long v) {
    return v > 0;
  }
  static boolean checkHouseNumberOfLifts(int v) {
    return v < 0;
  }
}

Enter valid house number of floors: abc
Enter valid house number of floors: 0
Enter valid house number of floors: 1
Enter valid house number of lifts: abc
Enter valid house number of lifts: 0
Enter valid house number of lifts: -1
houseNumberOfFloors=1
houseNumberOfLifts=-1