Taking inputs with BufferedReader in Java

Question

I have a bit of an annoying case here; wherein I am not able to take the input properly. I have always taken input via Scanner, and am not used to the BufferedReader.

INPUT FORMAT

First line contains T, which is an integer representing the number of test cases.
T cases follow. Each case consists of two lines.

First line has the string S. 
The second line contains two integers M, P separated by a space.

EXAMPLE

Input:
2
AbcDef
1 2
abcabc
1 1

My code so far:

public static void main (String[] args) throws java.lang.Exception
{
    BufferedReader inp = new BufferedReader (new InputStreamReader(System.in));
    int T= Integer.parseInt(inp.readLine());

    for(int i=0;i<T;i++) {
        String s= inp.readLine();
        int[] m= new int[2];
        m[0]=inp.read();
        m[1]=inp.read();

        // Checking whether I am taking the inputs correctly
        System.out.println(s);
        System.out.println(m[0]);
        System.out.println(m[1]);
    }
}

When inputting to the above example shown, I get the following output:

AbcDef
9
49
2
9
97

your m[0]=inp.read(); is reading a byte or something. do a readline into a string and split it to get the two fields, then parse them to ints. — Ray Tayek, Nov 16 '12 at 06:36
`inp.read()` will read a single character(16 bit) not byte(8 bit). — Subhrajyoti Majumder, Nov 16 '12 at 06:47

score 16 · Accepted Answer · edited May 23 '17 at 11:46

BufferedReader#read reads single character[0 to 65535 (0x00-0xffff)] from the stream, so it is not possible to read single integer from stream.

            String s= inp.readLine();
            int[] m= new int[2];
            String[] s1 = inp.readLine().split(" ");
            m[0]=Integer.parseInt(s1[0]);
            m[1]=Integer.parseInt(s1[1]);

            // Checking whether I am taking the inputs correctly
            System.out.println(s);
            System.out.println(m[0]);
            System.out.println(m[1]);

You can check also Scanner vs. BufferedReader.

score 1 · Answer 2 · answered Jul 04 '17 at 16:05

You can't read individual integers in a single line separately using BufferedReader as you do using Scannerclass. Although, you can do something like this in regard to your query :

import java.io.*;
class Test
{
   public static void main(String args[])throws IOException
    {
       BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
       int t=Integer.parseInt(br.readLine());
       for(int i=0;i<t;i++)
       {
         String str=br.readLine();
         String num[]=br.readLine().split(" ");
         int num1=Integer.parseInt(num[0]);
         int num2=Integer.parseInt(num[1]);
         //rest of your code
       }
    }
}

I hope this will help you.

Taking inputs with BufferedReader in Java

2 Answers2