Compare two files using Java

The program will prompt for 2 file names(.txt) that are to be compared. Given the file names, this program will compare the two files.

If any difference is there, it will print the differences and no. of differences in command prompt. 

If no difference is there, it will print

"files are equal".

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

//defining class

public class myfilereader
{
//defining main function
 public static void main (String[] args) throws java.io.IOException
    {
  //Getting the name of the files to be compared.
  BufferedReader br2 = new BufferedReader (new
InputStreamReader(System.in));
  System.out.println("Enter 1st File name:");
    String str = br2.readLine();
    System.out.println("Enter 2nd File name:");
    String str1 = br2.readLine();

  String s1="";
    String s2="",s3="",s4="";
    String y="",z="";

        //Reading the contents of the files
   BufferedReader br = new BufferedReader (new FileReader (str));
    BufferedReader br1 = new BufferedReader (new FileReader (str1));

   while((z=br1.readLine())!=null)
    s3+=z;

  while((y=br.readLine())!=null)
     s1+=y;

  System.out.println ();

        //String tokenizing
    int numTokens = 0;
    StringTokenizer st = new StringTokenizer (s1);
    String[] a = new String[10000];
    for(int l=0;l<10000;l++)
      {a[l]="";}
    int i=0;
    while (st.hasMoreTokens())
      {
        s2 = st.nextToken();
          a[i]=s2;
   i++;
            numTokens++;
      }

      int numTokens1 = 0;
     StringTokenizer st1 = new StringTokenizer (s3);
     String[] b = new String[10000];
     for(int k=0;k<10000;k++)
      {b[k]="";}
     int j=0;
     while (st1.hasMoreTokens())
       {
        s4 = st1.nextToken();
        b[j]=s4;
        j++;
        numTokens1++;
       }

//comparing the contents of the files and printing the differences, if any.
  int x=0;
      for(int m=0;m<a.length;m++)
      {
   if(a[m].equals(b[m])){}
    else
    {
     x++;
  System.out.println(a[m] + " -- " +b[m]);
  System.out.println();}
      }
 System.out.println("No. of differences : " + x);
 if(x>0){System.out.println("Files are not equal");}
 else{System.out.println("Files are equal. No difference found");}

 }
}