CountChar

public class CountChar {
  public static int getChar(String str, char chr) {
    int count = 0, pos = 0;
    while (str.indexOf(chr, pos) != -1) {
      count++; pos++;
    }
    return count;
  }

  public static void main(String[] args) {
    System.out.println("a in aaaa: " + getChar("aaaa", 'a'));
    System.out.println("b in aaaa: " + getChar("aaaa", 'b'));
  }
}