Vowel Count in Java

The challenge

Return the number (count) of vowels in the given string. 

We will consider a, e, i, o, u as vowels for this challenge (but not y).

The input string will only consist of lower case letters and/or spaces.

The solution in Java code

Option 1:

public class Vowels {

  public static int getCount(String str) {
    int vowelsCount = 0;
    char[] chars = str.toCharArray();
    for (char c : chars) {
      if (c=='a' || c=='e' || c=='i' || c=='o' || c=='u')
        vowelsCount++;
    }
    return vowelsCount;
  }

}

Option 2:

public class Vowels {

    public static int getCount(String str) {
        return str.replaceAll("(?i)[^aeiou]", "").length();
    }

}

Option 3:

public class Vowels {

  public static int getCount(String str) {
    return (int) str.chars().filter(c -> "aeiou".indexOf(c) >= 0).count();
  }

}

Test cases to validate our solution

import org.junit.Test;
import static org.junit.Assert.assertEquals;

public class VowelsTest {
    @Test
    public void testCase1() {
      assertEquals("Nope!", 5, Vowels.getCount("abracadabra"));
    }
    
}