How to split strings based on "/n" in Java

Question

I have got a string

$key1={331015EA261D38A7}
$key2={9145A98BA37617DE}
$key3={EF745F23AA67243D}

How do i split each of the keys based on "$" and the "next line" element? and then place it in an Arraylist?

The output should look like this: Arraylist[0]:

$key1={331015EA261D38A7}

Arraylist[1]:

$key2={9145A98BA37617DE}

Arraylist[2]:

$key3={EF745F23AA67243D}

Can you share the output you're trying to get for this sample? It would make the question much clearer. — Mureinik, Oct 08 '16 at 10:37
Possible duplicate of [How to split a string in Java](http://stackoverflow.com/questions/3481828/how-to-split-a-string-in-java) — Ambrish, Oct 08 '16 at 10:41
By `Arraylist` you mean actual instance of ArrayList (like `ArrayList lines = ..; //rest of code which fills that list`), or simple array of Strings `String[] lines = ...`? — Pshemo, Oct 08 '16 at 11:05

score 3 · Answer 1 · answered Oct 08 '16 at 10:39

3

If you just want to split by new line, it is as simple as :

yourstring.split("\n"):

answered Oct 08 '16 at 10:39

aleroot

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score 0 · Answer 2 · answered Oct 08 '16 at 10:43

0

yourstring.split(System.getProperty("line.separator"));

answered Oct 08 '16 at 10:43

Simon Ludwig

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This will work only if text uses same line separator in defined in system, which is not guaranteed. – Pshemo Oct 08 '16 at 10:51
Yes, right. but also its system independent – Simon Ludwig Oct 08 '16 at 10:55
@SimonLudwig I think you misunderstand. If you are parsing a file, it has the linebreaks it has. The system is irrelevant. Using the system line separator is not the right choice; avoiding the line separator entirely is. – Boris the Spider Oct 08 '16 at 10:58
"but also its system independent" quite opposite. Value of `System.getProperty("line.separator")` depends **only** on system. For instance if I create file on Linux where lines are separated with `\n` and will try to split it on Windows which is using `\r\n` then your solution can't work since `\r\n` will not match `\n`. If you are looking for independent solution than you can try with `\r?\n|\r` (since `split` is using regex). – Pshemo Oct 08 '16 at 10:58

score 0 · Accepted Answer · answered Oct 08 '16 at 10:46

0

Don't split, search your String for key value pairs:

\$(?<key>[^=]++)=\{(?<value>[^}]++)\}

For example:

final Pattern pattern = Pattern.compile("\\$(?<key>[^=]++)=\\{(?<value>[^}]++)\\}");
final String input = "$key1={331015EA261D38A7}\n$key2={9145A98BA37617DE}\n$key3={EF745F23AA67243D}";
final Matcher matcher = pattern.matcher(input);
final Map<String, String> parse = new HashMap<>();
while (matcher.find()) {
    parse.put(matcher.group("key"), matcher.group("value"));
}
//print values
parse.forEach((k, v) -> System.out.printf("Key '%s' has value '%s'%n", k, v));

Output:

Key 'key1' has value '331015EA261D38A7'
Key 'key2' has value '9145A98BA37617DE'
Key 'key3' has value 'EF745F23AA67243D'

answered Oct 08 '16 at 10:46

Boris the Spider

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Yes. You are the saviour xD – Shawn Oct 08 '16 at 11:19
Boris, how do i change the regex so that $key1="331015EA261D38A7" format can also be filter by the regex? – Shawn Oct 08 '16 at 11:30
@Shawn replace the curly brackets with quotes. Or get rid of them altogether and strip off whatever characters need to be removed afterwards. – Boris the Spider Oct 08 '16 at 12:41

How to split strings based on "/n" in Java

3 Answers3