Replace text in StringBuilder via regex

Question

I would like to replace some texts in StringBuilder. How to do this?

In this code I got java.lang.StringIndexOutOfBoundsException at line with mat

Answer 1

Maybe:

    int lookIndex = 0;
    while (lookIndex < builder.length() && matcher.find(lookIndex)) {
        lookIndex = matcher.start()+1;
        builder.replace(matcher.start(), matcher.end(), repl);
    }

...?

.find(n) with an integer argument claims to reset the matcher before it starts looking at the specified index. That would work around the issues raised in maartinus comment above.