Regex to split a string (in Java) so that spaces are preserved?

Question

I need to split a string (in Java) into individual words ... but I need to preserve spaces.

An example of the text I need to split is something like this:
ABC . . . . DEF . . . . GHI

I need to see "ABC", " . . . .", "DEF", ". . . .", and "GHI".

Obviously splitting on the space character \s isn't going to work, as all the spaces get swallowed up as one space.

Any suggestions?

Thanks

Answer 1

Looks like you can just split on \b in this case ("\\b" as a string literal).

Generally you want to split on zero-width matching constructs, which \b is, but also lookarounds can be used.

Related questions

• Java split is eating my characters.

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Splitting based on a custom word boundary

If \b isn't fitting your definition, you can always define your own boundaries using assertions.

For example, the following regex splits on the boundary between a meta character class X and its complement

(?=[X])(?<=[^X])|(?=[^X])(?<=[X])

In the following example, we define X to be \d:

    System.out.println(java.util.Arrays.toString(
        "007james123bond".split(
            "(?=[X])(?<=[^X])|(?=[^X])(?<=[X])".replace("X", "\\d")
        )
    )); // prints "[007, james, 123, bond]"

Here's another example where X is a-z$:

    System.out.println(java.util.Arrays.toString(
        "$dollar . . blah-blah   $more gimme".split(
            "(?=[X])(?<=[^X])|(?=[^X])(?<=[X])".replace("X", "a-z$")
        )
    )); // prints "[$dollar,  . . , blah, -, blah,    , $more,  , gimme]"

Answer 2

Thanks guys, that gave me the lead I needed ... I'm using (?<=[\\s]) and it works exactly the way I want!