How can I split a string in Java and retain the delimiters?

Question

I have this string (Java 1.5):

:alpha;beta:gamma;delta

I need to get an array:

{\":alpha\", \";beta\", \":gamma\", \";delta         


        

Answer 1

This should work with Java 1.5 (Pattern.quote was introduced in Java 1.5).

// Split the string on delimiter, but don't delete the delimiter
private String[] splitStringOnDelimiter(String text, String delimiter, String safeSequence){
    // A temporary delimiter must be added as Java split method deletes the delimiter

    // for safeSequence use something that doesn't occur in your texts 
    text=text.replaceAll(Pattern.quote(delimiter), safeSequence+delimiter);
    return text.split(Pattern.quote(safeSequence));
}

If first element is the problem:

private String[] splitStringOnDelimiter(String text, String delimiter, String safeSequence){
    text=text.replaceAll(Pattern.quote(delimiter), safeSequence+delimiter);
    String[] tempArray = text.split(Pattern.quote(safeSequence));
    String[] returnArray = new String[tempArray.length-1];
    System.arraycopy(tempArray, 1, returnArray, 0, returnArray.length);
    return returnArray;
}

E.g., here "a" is the delimiter:

splitStringOnDelimiter("-asd-asd-g----10-9asdas jadd", "a", "<>")

You get this:

1.: -
2.: asd-
3.: asd-g----10-9
4.: asd
5.: as j
6.: add

If you in fact want this:

1.: -a
2.: sd-a
3.: sd-g----10-9a
4.: sda
5.: s ja
6.: dd

You switch:

safeSequence+delimiter

with

delimiter+safeSequence