string vowels program in java

1String str = "hello";
2String vowels = "aeiou";
3
4for(char c : str) if(vowels.contains(c)) System.out.println(c + "");

1import java.util.Scanner;
2import java.util.*;
3
4class Test{
5    
6    public static boolean isVowel(char ch){
7        if(ch == 'A' || ch == 'a' || ch == 'E' || ch == 'e' || ch == 'i' || ch == 'I' || ch == 'o' || ch == 'O' || ch == 'u' || ch == 'U'){
8            return true;
9        }
10        return false;
11    }
12    
13    public static void main(String args[]){
14        
15        Scanner scan = new Scanner(System.in);
16        List<String> arr = new ArrayList<String>();
17        String str = scan.nextLine();
18        String words[] = str.split("\\s");
19        
20        for(String k: words){
21            boolean flag = false;
22            boolean f1 = true;
23            boolean f2 = true;
24            if(k.length()<=2){
25                continue;
26            }
27            for(int i = 0 ; i < k.length() ; i = i + 2){
28                if(isVowel(k.charAt(i))==false){
29                    f1 = false;
30                    break;
31                }
32            }
33            for(int i = 1 ; i < k.length() ; i = i + 2){
34                if(isVowel(k.charAt(i))==false){
35                    f2 = false;
36                    break;
37                }
38            }
39            if(f1 == true || f2 == true){
40                flag = true;
41            }
42            if(flag == true){
43                arr.add(k);
44            }
45        }
46        if(arr.size()==0){
47            System.out.print(-1);
48        }
49        else{
50            for(int i = 0 ; i < arr.size() ; i++)
51            {
52                System.out.print(arr.get(i) + " ");
53            }
54        }
55        scan.close();
56    }
57    
58}