Replace InputStream by applying regex on it

Question

I have an InputStream and I need to apply regex on it. I need an OutputStream as a return value since it should be forwarded to api. I do this:

// get byte stream
InputStream input = ...;
OutputStream output;

ReplacingInputStream test = new ReplacingInputStream(input, "\\s+", " ");
String inputText = IOUtils.toString(test, StandardCharsets.UTF_8);
System.out.println(inputText); // nothing is changed

but nothing is changed in input. I couldn't figure out how to do it, so I did

String inputText = IOUtils.toString(input, StandardCharsets.UTF_8);
inputText = inputText.replaceAll("\\s+", " ").trim(); // 
System.out.println(inputText); // Changed

This is quick and easy, but of course does not scale nicely to large streams (because perhaps run out of memory)

You did use test as InputStream i.o. input? Like: InputStream oldInput; InputStream input = new ReplacingInputStream(oldIInput, "\\s+", " "); — Joop Eggen
– Joop Eggen, Commented Feb 12, 2020 at 13:02

Max Sidnin · Accepted Answer · 2020-02-12 13:27:08Z

1

It looks like the 'pattern' parameter is not a Regexp pattern at all and even not a wildcard. It's just a string-to-string replacement.

If we're talking about 'org.apache.poi.util.ReplacingInputStream'.

answered Feb 12, 2020 at 13:27

Max Sidnin

361 bronze badge

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Replace InputStream by applying regex on it

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related