在Java中使用Regex拆分字符串

Question

Would anyone be able to assist me with some regex.

I want to split the following string into a number, string number

"810LN15"

1 method requires 810 to be returned, another requires LN and another should return 15.

The only real solution to this is using regex as the numbers will grow in length

What regex can I used to accomodate this?

Answer 1

String.split won't give you the desired result, which I guess would be "810", "LN", "15", since it would have to look for a token to split at and would strip that token.

Try Pattern and Matcher instead, using this regex: (\\d+)|([a-zA-Z]+) , which would match any sequence of numbers and letters and get distinct number/text groups (ie "AA810LN15QQ12345" would result in the groups "AA", "810", "LN", "15", "QQ" and "12345").

Example:

Pattern p = Pattern.compile("(\\d+)|([a-zA-Z]+)");
Matcher m = p.matcher("810LN15");
List<String> tokens = new LinkedList<String>();
while(m.find())
{
  String token = m.group( 1 ); //group 0 is always the entire match   
  tokens.add(token);
}
//now iterate through 'tokens' and check whether you have a number or text

Answer 2

In Java, as in most regex flavors (Python being a notable exception), the split() regex isn't required to consume any characters when it finds a match. Here I've used lookaheads and lookbehinds to match any position that has a digit one side of it and a non-digit on the other:

String source = "810LN15";
String[] parts = source.split("(?<=\\d)(?=\\D)|(?<=\\D)(?=\\d)");
System.out.println(Arrays.toString(parts));

output:

[810, LN, 15]

Answer 3

(\\\\d+)([a-zA-Z]+)(\\\\d+) should do the trick. The first capture group will be the first number, the second capture group will be the letters in between and the third capture group will be the second number. The double backslashes are for java.

Answer 4

This gives you the exact thing you guys are looking for

        Pattern p = Pattern.compile("(([a-zA-Z]+)|(\\d+))|((\\d+)|([a-zA-Z]+))");
        Matcher m = p.matcher("810LN15");
        List<Object> tokens = new LinkedList<Object>();
        while(m.find())
        {
          String token = m.group( 1 ); 
          tokens.add(token);
        }
        System.out.println(tokens);