How to find the longest repeated substring of given string

Question

I am new java and I was given assignment to find the longest substring of a string. I research online and seems that good way of approaching this problem will be implementi

Answer 1

public static void main(String[] args) {
        String str = "testingString";
        char[] strArr = str.toCharArray();
        StringBuilder bm = new StringBuilder();
        boolean isPresent = false;
        int len = strArr.length;
        int initial =0;
        int dinitial=0;

        HashMap hm = new HashMap();
        HashMap hl = new HashMap();
        while(initial<=len-1 && !(dinitial>=len-1)){
            if(!hm.isEmpty()){
                isPresent = hm.containsValue(strArr[initial]+"");
                if(!isPresent){
                    bm.append(strArr[initial]);
                    hm.put(strArr[initial]+"",strArr[initial]+"");
                    if(initial==len-1){
                        System.out.println("Longest substring is::" + bm);
                        break;
                    }
                }
                else if(isPresent){
                    System.out.println("Longest substring is::" + bm);
                    bm.delete(0, bm.length());
                    ++dinitial;
                    initial--;
                    hm.clear();
                }
                initial++;
            }
            else
            {
                    bm.append(strArr[initial]);
                    hm.put(strArr[initial]+"",strArr[initial]+"");
                    initial++;
            }
        }
        hm.clear();
    }