Just use:

String[] terms = input.split("[\\s@&.?$+-]+");

You can put a short-hand character class inside a character class (note the \s), and most meta-character loses their meaning inside a character class, except for [, ], -, &, \. However, & is meaningful only when comes in pair &&, and - is treated as literal character if put at the beginning or the end of the character class.

Other languages may have different rules for parsing the pattern, but the rule about - applies for most of the engines.

As @Sean Patrick Floyd mentioned in his answer, the important thing boils down to defining what constitute a word. \w in Java is equivalent to [a-zA-Z0-9_] (English letters upper and lower case, digits and underscore), and therefore, \W consists of all other characters. If you want to consider Unicode letters and digits, you may want to look at Unicode character classes.

I'm assuming you did something like:

String[] parts = str.split("^");

That doesn't work because the argument to split is actually a regular expression, where ^ has a special meaning. Try this instead:

String[] parts = str.split("\\^");

The \\ is really equivalent to a single \ (the first \ is required as a Java escape sequence in string literals). It is then a special character in regular expressions which means "use the next character literally, don't interpret its special meaning".

Using split("\\|") is the same as split("\\|", 0), where the limit parameter 0 tells the function "omit trailing empty strings". So you are missing the last two empty strings. Use the two-argument version and supply a negative number to obtain all parts (even trailing empty ones):

str.split("\\|", -1)

You can split by , followed by an optional blank characters \s* with a negative lookahead. This Regex would identify the commas qualified to split the input String.

,(?![^,]+"\s*,)\s*

The explanation is below and the demo is here: https://regex101.com/r/ghNMVo/1:

• , is a comma literally
• (?![^,]+"\s*,) is a negative lookahead that matches if the following characters listed between (?!...) are not found right after the comma (,). This basically identifies the end of a String followed by the comma (ex. ...four",) which means, the previous comma is not matched for split as long as a String follows.
  • [^,]+ at least one character except for the comma itself
  • " followed by the " matched literally
  • \s* any number of blank characters
  • , followed by the , matched literally
• \s* are optional blank characters

When applied to Java, don't forget to escape the characters.

final String string = "1,2,3,4,5,\"one, two\", 6, 7, \"three, four\", 8, 9";
final String[] array = string.split(",(?![^,]+\"\\s*,)\\s*");
Arrays.asList(array).forEach(System.out::println);

1
2
3
4
5
"one, two"
6
7
"three, four"
8
9

try this:
String[] cs = s.split("");

Try to use Pattern.quote to avoid escaping character by character, It will do that free for you :

String[] suburl = mySuburl.split(Pattern.quote("-{name-of-perpetrators"));

The split() method on String takes a RegEx. What you are passing is an invalid RegEx. You are better off using the substring() function as you already know the prefix and suffix pattern.

test = test.substring(patternOne.length(), test.length() - patternTwo.length());

Use the appropriately named method String#split().

String string = "004-034556";
String[] parts = string.split("-");
String part1 = parts[0]; // 004
String part2 = parts[1]; // 034556

Note that split's argument is assumed to be a regular expression, so remember to escape special characters if necessary.

there are 12 characters with special meanings: the backslash \, the caret ^, the dollar sign $, the period or dot ., the vertical bar or pipe symbol |, the question mark ?, the asterisk or star *, the plus sign +, the opening parenthesis (, the closing parenthesis ), and the opening square bracket [, the opening curly brace {, These special characters are often called "metacharacters".

For instance, to split on a period/dot . (which means "any character" in regex), use either backslash \ to escape the individual special character like so split("\\."), or use character class [] to represent literal character(s) like so split("[.]"), or use Pattern#quote() to escape the entire string like so split(Pattern.quote(".")).

String[] parts = string.split(Pattern.quote(".")); // Split on the exact string.

To test beforehand if the string contains certain character(s), just use String#contains().

if (string.contains("-")) {
    // Split it.
} else {
    throw new IllegalArgumentException("String " + string + " does not contain -");
}

Note, this does not take a regular expression. For that, use String#matches() instead.

If you'd like to retain the split character in the resulting parts, then make use of positive lookaround. In case you want to have the split character to end up in left hand side, use positive lookbehind by prefixing ?<= group on the pattern.

String string = "004-034556";
String[] parts = string.split("(?<=-)");
String part1 = parts[0]; // 004-
String part2 = parts[1]; // 034556

In case you want to have the split character to end up in right hand side, use positive lookahead by prefixing ?= group on the pattern.

String string = "004-034556";
String[] parts = string.split("(?=-)");
String part1 = parts[0]; // 004
String part2 = parts[1]; // -034556

If you'd like to limit the number of resulting parts, then you can supply the desired number as 2nd argument of split() method.

String string = "004-034556-42";
String[] parts = string.split("-", 2);
String part1 = parts[0]; // 004
String part2 = parts[1]; // 034556-42