Scaner

package com.company;

import java.io.*;
import java.util.NoSuchElementException;

public class MyScanner {

    private BufferedReader reader;

    public MyScanner( InputStream in ){
        reader = new BufferedReader( new InputStreamReader( in ) );
    }

    private String curString;

    private String getCurString() throws IOException {
        return reader.readLine();
    }

    private boolean isNotDoubleCheck = true;

    public boolean hasNextLine() throws IOException {
        if( isNotDoubleCheck ){
            curString = getCurString();
        }
        isNotDoubleCheck = false;
        return !curString.isEmpty();
    }


    public String nextLine() throws IOException {
        if( hasNextLine() ){
            isNotDoubleCheck = true;
            return curString;
        }
        else{
            isNotDoubleCheck = true;
            throw new NoSuchElementException( "Next line not found" );
        }

    }
}