Question

I am having great issues searching a string for particular parameters that are needed in my application, I am under the assumption that the only real way to do this is using regular expressions however they are giving me a huge headache! I don’t usually write them myself but get them off other websites however what i need isn’t simple enough to be included 🙁

Here is the string:

10 50 u E2U+pstn:tel "!^(.*)$!tel:\\1;spn=42180;mcc=234;mnc=33!" .

I need to extract the spn, mcc, and the mnc from this string. Unfortunately the api i call changes the location of these on the string for some requests which makes indexing the string difficult. I really need to list what i need to grab the spn= for example then follow off and read the number but everything i try never works.

Answer 1

A solution using Pattern and Matcher:

String s = "10 50 u E2U+pstn:tel \"!^(.*)$!tel:\\\\1;spn=42180;mcc=234;mnc=33!\"";
Pattern p = Pattern.compile("^.*spn=([0-9]+);mcc=([0-9]*);mnc=([0-9]*)!.*$");
Matcher matcher = p.matcher(s);
matcher.matches(); // true
String spn = matcher.group(1); // 42180
String mcc = matcher.group(2); // 234
String mnc = matcher.group(3); // 33

Edit: You can use named-capturing groups, too:

Pattern p =
  Pattern.compile("^.*spn=(?<spn>[0-9]+);mcc=(?<mcc>[0-9]*);mnc=(?<mnc>[0-9]*)!.*$");
Matcher matcher = p.matcher(s);
matcher.matches(); // true
String spn = matcher.group("spn");
String mcc = matcher.group("mcc");
String mnc = matcher.group("mnc");