How to remove everything from a string except for a specific pattern?

Question

Java

There is a line:

"<какой-то текст или символы>130 кг<какой-то текст или символы>"

it is necessary to remove everything from the line, except for 130 kg.
In this case, instead of 130, there can be any number

Answer 1

It is possible to do this, provided that it is a single number with two or more signs:

String str = "<какой-то текст или символы>130 кг<какой-то текст или символы>";
String substr = str.replaceAll("\\d{2,}| кг", "");
String output= str.replaceAll(substr, "");
System.out.println(output);

Answer 2

Regular season of course