Java KMP(The Knuth-Morris-Pratt Algorithm) Search

public class Match {
    public static void main(String[] args) {
        String str2 = "ACACABAC";
        String str1="ABCDACACACACABAC";
        int[] ints = kmpMatch(str2);
        int i = kmpSearch(str1, str2, ints);
        System.out.println(Arrays.toString(ints));
        System.out.println(i);
    }
    public static int violenceMatch(String str1, String str2) {
        char[] s1 = str1.toCharArray();
        char[] s2 = str2.toCharArray();
        int i = 0;
        int j = 0;
        while (i < s1.length && j < s2.length) {
            if (s1[i] == s2[j]) {
                i++;
                j++;
            } else {
                i = i - j + 1;
                j = 0;
            }
        }
        if (j == s2.length)
            return i - j;
        else return -1;
    }
 
    public static int[] kmpMatch(String dest) {
        int[] match = new int[dest.length()];
        match[0] = 0;
        for (int i = 1, j = 0; i < dest.length(); i++) {
            while (j > 0 && dest.charAt(i) != dest.charAt(j)) {
                j = match[j - 1];
            }
            if (dest.charAt(i) == dest.charAt(j))
                j++;
            match[i] = j;
        }
        return match;
    }
 
    public static int kmpSearch(String str1, String str2, int[] match) {
        int i=0;
        int j=0;
        while (i<str1.length()&&j<str2.length()){
            while (j > 0 && str1.charAt(i) != str2.charAt(j)) {
                j = match[j - 1];
            }
            if (str1.charAt(i) == str2.charAt(j))
                j++;
            if (j == str2.length())
                return i - j + 1;
            i++;
        }
        return -1;// not found
    }
}