在JAVA中计算子字符串忽略大小写的次数

Question

I am trying to count the occurences of div tag in my html file. When I search for div , I get 2 and for DIV , I get 1650. So ideally when i use sHtml.toUpperCase() , and then search for DIV , I should get 1652 . But I am getting 1656 . What might be going wrong here?

        /********* Counting occurences of div **************/
        String findString = "DIV";
        int lastIndex = 0;
        int count = 0;

        while (lastIndex != -1) {

            lastIndex = sHtml.indexOf(findString, lastIndex);

            if (lastIndex != -1) {
                count++;
                lastIndex += findString.length();
            }
        }
        System.out.println("Count of div = " + count);

Answer 1

You are picking up substrings that were mixed-case before - say, Div . This is not a good reason to count "div" s, though, because you would pick up parts of longer words (say, Division or Divorce ).

If you want a better count, you could use a simple regex to do the counting:

"[</]div[ />]"

This regular expression will match a div that is preceded by < or / , and followed by a space, / , or > :

Pattern countRx = Pattern.compile("[</]div[ />]", Pattern.CASE_INSENSITIVE);
Matcher m = countRx.matcher(sHtml);
int count = 0;
while (m.find()) {
    count++;
}
System.out.println(count);

Answer 2

By the process of elimination, you must have some combination of Div , DIv , DiV or dIV as well. It is also possible that your text contains a word with div in it (like long division ).