How to get a string between two characters?

There's probably a really neat RegExp, but I'm noob in that area, so instead...

String s = "test string (67)";

s = s.substring(s.indexOf("(") + 1);
s = s.substring(0, s.indexOf(")"));

System.out.println(s);

A very useful solution to this issue which doesn't require from you to do the indexOf is using Apache Commons libraries.

 StringUtils.substringBetween(s, "(", ")");

This method will allow you even handle even if there multiple occurrences of the closing string which wont be easy by looking for indexOf closing string.

You can download this library from here: https://mvnrepository.com/artifact/org.apache.commons/commons-lang3/3.4

Try it like this

String s="test string(67)";
String requiredString = s.substring(s.indexOf("(") + 1, s.indexOf(")"));

The method's signature for substring is:

s.substring(int start, int end);

By using regular expression :

 String s = "test string (67)";
 Pattern p = Pattern.compile("\\(.*?\\)");
 Matcher m = p.matcher(s);
 if(m.find())
    System.out.println(m.group().subSequence(1, m.group().length()-1)); 

Java supports Regular Expressions, but they're kind of cumbersome if you actually want to use them to extract matches. I think the easiest way to get at the string you want in your example is to just use the Regular Expression support in the String class's replaceAll method:

String x = "test string (67)".replaceAll(".*\\(|\\).*", "");
// x is now the String "67"

This simply deletes everything up-to-and-including the first (, and the same for the ) and everything thereafter. This just leaves the stuff between the parenthesis.

However, the result of this is still a String. If you want an integer result instead then you need to do another conversion:

int n = Integer.parseInt(x);
// n is now the integer 67