Java FileInputStream Example

Write a JAVA Program which reads an input file from the Command Line which contains the numbers sperated by space and find the average for the numbers.

SOLUTION: 

 
import java.io.File;
import java.io.FileInputStream;
import java.io.StreamTokenizer;

public class FileReadIntegers {
 public static void main(String[] args){
  
  if(args.length!=1){
   System.out.println("Please enter file name in proper format.");
   return;
  }
  
  //File object for checking file.
  File file = new File(args[0]);
  //Checking file
  if(file.exists()){
   System.out.printf("%s exists.\n",file.getName());
   System.out.println();
   if(file.isDirectory()){
    System.out.println(" But it is not a file.");
    return;
   }
  }
  else{
   System.out.println("File not exists.");
   return;
  }
  
  //Reading file ...
  float sum=0f;
  int j=0;
  try{
   FileInputStream fileRead = new FileInputStream(args[0]);
   @SuppressWarnings("deprecation")
   StreamTokenizer tokenizer = new StreamTokenizer(fileRead);
   
   while(tokenizer.nextToken()!=StreamTokenizer.TT_EOF){
    if(tokenizer.ttype==StreamTokenizer.TT_NUMBER){
     sum+=tokenizer.nval;
     j++;
    }
   }
   System.out.println("Average: "+(sum/j));
  }
  catch(Exception e) {
   System.out.println("Invalid file.");
  }
 }
}