java htmlunit button click doesnt work in for loop return NullPointerException

Question

       for(int i=0;i<=5;i++){
            HtmlPage currentPage = (HtmlPage)client.getPage("http:// http://testsite.com ");
            HtmlForm form = (HtmlForm) currentPage.getElementById("kelimeAraID");
            HtmlButton button = (HtmlButton) form.getElementsByTagName("button").get(0);
            HtmlTextInput kullaniciAdi= form.getInputByName("kelime");
            kullaniciAdi.setText(arrayList.get(i));
            HtmlPage sayfa2= button.click();
            HtmlTableRow tr=(HtmlTableRow)sayfa2.getFirstByXPath("//*[@id=\"hor-minimalist-a\"]/tbody/tr[1]");
            System.out.println(arrayList.get(i)+":"+tr.asText()); /*line:95*/
            client.closeAllWindows();
        }

Exception in thread "main" java.lang.NullPointerException at htmlunit.HtmlUnit.main(HtmlUnit.java:95)

Answer 1

That probably means that arrayList is shorter than 6 in the error case.

Try this:

if(i < arrayList.size()){
  System.out.println(arrayList.get(i)+":"+tr.asText());
}else {
  System.out.println("XXX":"+tr.asText());
}