Java Regex replacement for negative bytes in string

Question

I'm getting a date from a web (html): " abril 2013 Viernes 19"

I've tried all normal regex with no success.

Finally I discovered the string bytes (str.getBytes()), and this are the values:

[-96, 97, 98, 114, 105, 108, -96, -96, -96, 50, 48, 49, 51, -96, -96, 86, 105, 101, 114, 110, 101, 115, -96, 49, 57]

What are this -96?

how to replace 1 or more -96 or whatever empty space is by 1 space?

It's not clear what you're trying to do here. Why do you want to replace these negative bytes? — Vivin Paliath, Apr 19 '13 at 16:31
Why are you using a regex to parse a date? Have you tried [SimpleDateFormat](http://docs.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html)? — parsifal, Apr 19 '13 at 17:50

score 4 · Answer 1 · answered Apr 19 '13 at 16:39

4

The byte -96 (A0 in hexadecimal, or 160 as an unsigned byte), is the non-breaking space in the ISO-8859-1 character encoding, which is probably the encoding you used to transform the string to bytes.

answered Apr 19 '13 at 16:39

JB Nizet

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@rgettman I think there's a serial downvoter in this thread. A bunch of my posts were downvoted, but then the system picked it up and reverted most of them. – Vivin Paliath Apr 19 '13 at 16:56

score 4 · Answer 2 · answered Apr 19 '13 at 16:39

4

The first byte (-96) is negative because in Java bytes are signed. It corresponds to character 160 (256 - 96), which is a non-breaking space. You'll need to specify that character directly in your regular expression.

str = str.replaceAll(String.valueOf((char) -96), " ");

answered Apr 19 '13 at 16:39

rgettman

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@rgettman When I first saw the answer, I thought it will work, but I've tried and **doesn't work**. Any suggestions? – surfealokesea Apr 22 '13 at 06:05

score 1 · Accepted Answer · edited May 23 '17 at 10:25

1

You should be able to use the Character.isSpaceChar function to do this. As mentioned in a response to a related question, you can use it in a java regex like this:

String sampleString = "\u00A0abril\u00A0\u00A02013\u00A0Viernes\u00A019";
String result = sampleString.replaceAll("\\p{javaSpaceChar}", " ");

I think that will do exactly what you want while avoiding any need to deal with raw bytes.

edited May 23 '17 at 10:25

Community

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answered Apr 22 '13 at 06:45

DaoWen

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Yes, that works, thanks a lot! str.replaceAll("\\p{javaSpaceChar}+", " ").trim(); – surfealokesea Apr 22 '13 at 08:43

score 0 · Answer 4 · answered Apr 22 '13 at 06:31

I fixed this way (please if anyone have a better answer I'll appreciate it):

byte[] b=str.getBytes();
for (int i = 0; i < b.length; i++) {
    if (b[i]==-96)
        b[i]=" ".getBytes()[0];
}
String strOut=new String(b).trim();
Pattern blank=Pattern.compile("\\s+|\b+|\t+|\n+|\f+|\r+");
strOut=blank.matcher(strOut).replaceAll(" ");

Thanks every body for help!

Java Regex replacement for negative bytes in string

4 Answers4