An alternative to processing the string directly would be to use a regular expression with capturing groups. This has the advantage that it makes it straightforward to imply more sophisticated constraints on the input. For example, the following splits the string into two parts, and ensures that both consist only of digits:

import java.util.regex.Pattern;
import java.util.regex.Matcher;

class SplitExample
{
    private static Pattern twopart = Pattern.compile("(\\d+)-(\\d+)");

    public static void checkString(String s)
    {
        Matcher m = twopart.matcher(s);
        if (m.matches()) {
            System.out.println(s + " matches; first part is " + m.group(1) +
                               ", second part is " + m.group(2) + ".");
        } else {
            System.out.println(s + " does not match.");
        }
    }

    public static void main(String[] args) {
        checkString("123-4567");
        checkString("foo-bar");
        checkString("123-");
        checkString("-4567");
        checkString("123-4567-890");
    }
}

As the pattern is fixed in this instance, it can be compiled in advance and stored as a static member (initialised at class load time in the example). The regular expression is:

(\d+)-(\d+)

The parentheses denote the capturing groups; the string that matched that part of the regexp can be accessed by the Match.group() method, as shown. The \d matches and single decimal digit, and the + means "match one or more of the previous expression). The - has no special meaning, so just matches that character in the input. Note that you need to double-escape the backslashes when writing this as a Java string. Some other examples:

([A-Z]+)-([A-Z]+)          // Each part consists of only capital letters 
([^-]+)-([^-]+)            // Each part consists of characters other than -
([A-Z]{2})-(\d+)           // The first part is exactly two capital letters,
                           // the second consists of digits

I still suggest to use split(), it skips null tokens by default. you want to get rid of non numeric characters in the string and only keep pipes and numbers, then you can easily use split() to get what you want. or you can pass multiple delimiters to split (in form of regex) and this should work:

String[] splited = yourString.split("[\\|\\s]+");

and the regex:

import java.util.regex.*;

Pattern pattern = Pattern.compile("\\d+(?=([\\|\\s\\r\\n]))");
Matcher matcher = pattern.matcher(yourString);
while (matcher.find()) {
    System.out.println(matcher.group());
}

While the accepted answer is good, be aware that you will end up with a leading empty string if your input string starts with a white space. For example, with:

String str = " Hello I'm your String";
String[] splitStr = str.split("\\s+");

The result will be:

splitStr[0] == "";
splitStr[1] == "Hello";
splitStr[2] == "I'm";
splitStr[3] == "Your";
splitStr[4] == "String";

So you might want to trim your string before splitting it:

String str = " Hello I'm your String";
String[] splitStr = str.trim().split("\\s+");

[edit]

In addition to the trim caveat, you might want to consider the unicode non-breaking space character (U+00A0). This character prints just like a regular space in string, and often lurks in copy-pasted text from rich text editors or web pages. They are not handled by .trim() which tests for characters to remove using c <= ' '; \s will not catch them either.

Instead, you can use \p{Blank} but you need to enable unicode character support as well which the regular split won't do. For example, this will work: Pattern.compile("\\p{Blank}", UNICODE_CHARACTER_CLASS).split(words) but it won't do the trim part.

The following demonstrates the problem and provides a solution. It is far from optimal to rely on regex for this, but now that Java has 8bit / 16bit byte representation, an efficient solution for this becomes quite long.

public class SplitStringTest {
    static final Pattern TRIM_UNICODE_PATTERN = Pattern.compile("^\\p{Blank}*(.*)\\p{Blank}*$", UNICODE_CHARACTER_CLASS);
    static final Pattern SPLIT_SPACE_UNICODE_PATTERN = Pattern.compile("\\p{Blank}+", UNICODE_CHARACTER_CLASS);

    public static String[] trimSplitUnicodeBySpace(String str) {
        Matcher trimMatcher = TRIM_UNICODE_PATTERN.matcher(str);
        boolean ignored = trimMatcher.matches();
        return SPLIT_SPACE_UNICODE_PATTERN.split(trimMatcher.group(1));
    }

    @Test
    public void test() {
        String words = " Hello    I'm\u00A0your String\u00A0";
        // non-breaking space here --^ and there -----^

        String[] split = words.split(" ");
        String[] trimAndSplit = words.trim().split(" ");
        String[] splitUnicode = SPLIT_SPACE_UNICODE_PATTERN.split(words);
        String[] trimAndSplitUnicode = trimSplitUnicodeBySpace(words);

        System.out.println("words: [" + words + "]");
        System.out.println("split: [" + String.join("][", split) + "]");
        System.out.println("trimAndSplit: [" + String.join("][", trimAndSplit) + "]");
        System.out.println("splitUnicode: [" + String.join("][", splitUnicode) + "]");
        System.out.println("trimAndSplitUnicode: [" + String.join("][", trimAndSplitUnicode) + "]");
    }
}

Results in:

words: [ Hello    I'm your String ]
split: [][Hello][][][][I'm your][String ]
trimAndSplit: [Hello][][][][I'm your][String ]
splitUnicode: [][Hello][I'm][your][String]
trimAndSplitUnicode: [Hello][I'm][your][String]

In most regex dialects there are a set of convenient character summaries you can use for this kind of thing - these are good ones to remember:

\w - Matches any word character.

\W - Matches any nonword character.

\s - Matches any white-space character.

\S - Matches anything but white-space characters.

\d - Matches any digit.

\D - Matches anything except digits.

A search for "Regex Cheatsheets" should reward you with a whole lot of useful summaries.