java regular expression between characters java

Question

My Java code:

 String subjectString = "BYWW4 AterMux TP 46[_221]  \n"
                + "FHTTY TC AterMux TP 9  \n"
                + "TUI_OO AterMux TP 2[_225]  \n"
                + "F-UYRE TC AterMux TP 2  \n"
                + "RRRDSA AterMux TP 31[_256]  ";

        String textStr[] = subjectString.split("\n");
        for (int i = 0; i < textStr.length; i++) {
            String ResultString = null;
            try {
                Pattern regex = Pattern.compile("????????");
                Matcher regexMatcher = regex.matcher(textStr[i]);
                if (regexMatcher.find()) {
                    ResultString = regexMatcher.group();
                    System.out.println(ResultString); /// 
                }
            } catch (PatternSyntaxException ex) {
    // Syntax error in the regular expression
            }
        }

I want the program to print the value after word (TP) and before ([) on this code to get result like below:
46
9
2
2
31

Answer 1

You can use regexp TP\\s*(\\d+)\\[ (double backslashes in Java code) and get a value with regexMatcher.group(1) . But you should not recreate it on each iteration of the loop, you should use Pattern.compile once per regexp.