How to write a program that counts the number of words and lines in a file?

Question:

How to write a program that counts the number of words and lines in a file?

Code:

import java.util.*;
import java.io.*;
 
public class CountWords {
  public static void main(String[] args) throws FileNotFoundException {
    File file = new File("example.txt");
    Scanner in = new Scanner(new FileInputStream(file));
    countWords(in);
  }
 
  // Counts total lines and words in the input scanner.
  public static void countWords(Scanner input) {
 
    int lineCount=0;
    int wordCount=0;
 
    while(input.hasNextLine()) {
      String line = input.nextLine();
      lineCount++;
 
      String str[] = line.split((" "));
      for (int i=0;i<str.length;i++) {
        if (str[i].length()>0) {
          wordCount ++;
        }
      }
    }
 
    System.out.println("Lines: " + lineCount);
    System.out.println("Words: " + wordCount);
  }
}
 

Output:

$ cat example.txt 
this is line one 
this is line two
this is line three

$ java CountWords
Lines: 3
Words: 12