reading input till EOF in java

Question

In C++ if I wish to read input till the EOF I can do it in the following manner

while(scanf(\"%d\",&n))
{
    A[i]=n;
    i++;
}

I can

Answer 1

Here is my Java equivalent code to read input until End-of-File:

import java.util.Scanner;

public class EndOfFileSolutions {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        for(int i = 1; sc.hasNext()== true; i++){
            System.out.println(i + " " + sc.nextLine());
        }
    }
}

This code will produce output look like below --

Sample Input:

Hello world
I am a file
Read me until end-of-file.

Sample Output:

1 Hello world
2 I am a file
3 Read me until end-of-file.

This answer also works fine to solve Hackerrank EOF problem

Answer 2

A simple solution would be to use Scanner class.

See snipet below:

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

public class Solution {

    public static void main(String[] args) {

        Scanner s = new Scanner(System.in);
        while(s.hasNextLine())
        {
            String line = s.nextLine();
            System.out.println(line);
        }
    }
}

Answer 3

The only thing that really works for me (you don't even have to create a file)

Scanner read = new Scanner(System.in);
String cadena;
boolean cond = true;
int i =0;
while (cond){
    cadena = read.nextLine();
    if(cadena.isEmpty())
        cond = false;
}

Answer 4

In Java, One way of reading till EOF is:-

     Scanner scan = new Scanner(System.in);    
     while(scan.hasNextLine())   //read until condition is true
     {
        String line = scan.nextLine();
        System.out.println(line);
        i++;
     } 

Answer 5

Here is Java equivalent code using BufferedReader and FileReader classes.

  import java.io.BufferedReader;
  import java.io.FileReader;
  import java.io.IOException;

  public class SmallFileReader {
        public static void main(String[] args) throws IOException {  

Option 1:
String fileName = args[0];
BufferedReader br = new BufferedReader(new FileReader(fileName));
Option 2:
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter a file name: ");
String fileName = br.readLine();

             //BufferedReader br = new BufferedReader(new FileReader("Demo.txt"));
             String line=null;
             while( (line=br.readLine()) != null) {
                    System.out.println(line);  
             }
  }
}  

I made little modification to @Vallabh Code. @tom You can use the first option, if you want to input the file name through command line.
java SmallFileReader Hello.txt
Option 2 will ask you the file name when you run the file.

Answer 6

Here is Java equivalent code using BufferedReader and FileReader classes.

  import java.io.BufferedReader;
  import java.io.FileReader;
  import java.io.IOException;

  public class SmallFileReader {
        public static void main(String[] args) throws IOException {
             BufferedReader br = new BufferedReader(new FileReader("Demo.txt"));
             String line=nul;
             while( (line=br.readLine()) != null) {
                    System.out.println(line);  
             }
  }
}