Question

I have following String and i want to split this string into number of sub strings(by taking ‘,’ as a delimeter) when its length reaches 36. Its not exactly splitting on 36’th position

      String message = "This is some(sampletext), and has to be splited properly";

I want to get the output as two substrings follows:
1. ‘This is some (sampletext)’
2. ‘and has to be splited properly’

Thanks in advance.

Answer 1

A solution based on regex:

    String s = "This is some sample text and has to be splited properly";
    Pattern splitPattern = Pattern.compile(".{1,15}\\b");
    Matcher m = splitPattern.matcher(s);
    List<String> stringList = new ArrayList<String>();
    while (m.find()) {
        stringList.add(m.group(0).trim());
    }

Update:
trim() can be droped by changing the pattern to end in space or end of string:

    String s = "This is some sample text and has to be splited properly";
    Pattern splitPattern = Pattern.compile("(.{1,15})\\b( |$)");
    Matcher m = splitPattern.matcher(s);
    List<String> stringList = new ArrayList<String>();
    while (m.find()) {
        stringList.add(m.group(1));
    }

group(1) means that I only need the first part of the pattern (.{1,15}) as output.

.{1,15} – a sequence of any characters (“.”) with any length between 1 and 15 ({1,15})

\b – a word break (a non-character before of after any word)

( |$) – space or end of string

In addition I’ve added () surrounding .{1,15} so I can use it as a whole group (m.group(1)).
Depending on the desired result, this expression can be tweaked.

Update:
If you want to split message by comma only if it’s length would be over 36, try the following expression:

Pattern splitPattern = Pattern.compile("(.{1,36})\\b(,|$)");