how to take a substring of size n that repeats

Question

I have the following entry:

aaisndiaunwioun    test|test saiudb8iuyb aiwbu diby tab fiubaw palavragrande|palavragrande asibtiubi

How to make the algorithm return test and palavragrande only if it’s spelled the same before and after of the symbol index |

I did it but it obviously didn’t work

while (s1.indexOf("|") != -1) {
        for (int i = 1; i < 25; i++) {
            for (int j = 1; j < 25; j++) {
                String teste1 = s1.substring(s1.indexOf("|") + 1, s1.indexOf("|") + i);
                String teste2 = s1.substring(s1.indexOf("|") - j, s1.indexOf("|"));
                if (teste1.equals(teste2)) {
                    System.out.println(teste1);
                    char[] s1char = s1.toCharArray();
                    s1char[s1.indexOf("|")] = 'a';
                    s1 = String.valueOf(s1char);
                    System.out.println(s1);
                    System.out.println(s1.indexOf("|"));
                }

            }

Answer 1

You can use the indexOf("") to match the entire sentence:

public class Teste {

    private static final String CONST = "aaisndiaunwioun    test|test saiudb8iuyb aiwbu diby tab fiubaw palavragrande|palavragrande asibtiubi";

    public static void main(String[] args) {

        if(CONST.indexOf("test|test") >= 0) {
            System.out.println("test");
        }

        if(CONST.indexOf("palavragrande|palavragrande") >= 0) {
            System.out.println("palavragrande");
        }
    }
}

If the sentences "test|test" or "palavragrande|palavragrande" there is no indexOf("") will return -1.

---

EDIT

With the comments below I understood that this is not what I wanted.
I remade the answer but I’ll leave the original content example.
Follow the correct answer:

public class Teste {

    private static final String CONST = "aaisndiaunwioun    test|test saiudb8iuyb aiwbu diby tab fiubaw palavragrande|palavragrande asibtiubi";

    public static void main(String[] args) {

        int ultimaPosicaoDoPipe = 0;
        while(CONST.indexOf("|", ultimaPosicaoDoPipe) >= 0) {

            final int posicaoAtualDoPipe = CONST.indexOf("|", ultimaPosicaoDoPipe);
            final String palavraAntesDoPipe = getPalavraAntesDoPipe(ultimaPosicaoDoPipe, posicaoAtualDoPipe);
            final String palavraDepoisDoPipe = getPalavraDepoisDoPipe(posicaoAtualDoPipe);

            if(palavraAntesDoPipe.equals(palavraDepoisDoPipe)) {
                System.out.println(palavraAntesDoPipe);
            }

            ultimaPosicaoDoPipe = posicaoAtualDoPipe + 1;
        }
    }

    private static String getPalavraAntesDoPipe(final int ultimaPosicaoDoPipe, final int posicaoAtualDoPipe) {
        String palavraAntesDoPipe = CONST.substring(ultimaPosicaoDoPipe, posicaoAtualDoPipe);
        palavraAntesDoPipe = palavraAntesDoPipe.substring(palavraAntesDoPipe.lastIndexOf(" ") + 1);
        return palavraAntesDoPipe;
    }

    private static String getPalavraDepoisDoPipe(final int posicaoAtualDoPipe) {
        String palavraDepoisDoPipe = CONST.substring(posicaoAtualDoPipe + 1);
        palavraDepoisDoPipe = palavraDepoisDoPipe.substring(0, palavraDepoisDoPipe.indexOf(" "));
        return palavraDepoisDoPipe;
    }
}

Explanation:

The pipe character (|) is sought in loop through the overload of the method indexOf() which receives a second parameter that tells from which index it should look for the pipe.

From there, the methods getPalavraAntesDoPipe() and getPalavraDepoisDoPipe() return the words before and after the pipe (as it is to imagine :p).

Nothing too complex, just using class methods String.