如何在带有数字字符串的Java中正确使用模式

Question

I'm trying to use Pattern in Java and I'm having a problem.

I want to find from a String[] that contains numbers (that I retrieved from a file) if they match another string of numbers (also from a file).

Eg I have the number 1 and I want to search in a String like this: 5 10 1 8 6 3 -1 10 8 10 10 4 10 -1 10 10 10 10 9 10 -1 10 10 10 10 10 10 -1 10 10 10 10 10 10 -1 -2 .

Obviously the -1 and 10 are not what I'm locking for. Is there a way to solve this?

I can't use use Pattern.compile() with an integer.

Answer 1

There are two ways:

Pattern

Numbers in file are seperated by spaces,so you can write pattern like this

String number = "1";
String file = "5 10 1 8 6 3 -1 10 8 10 10 4 10 -1 10 10 10 10 9 10 -1 10 10 10 10 10 10 -1 10 10 10 10 10 10 -1 -2";
file = " " + file + " "; // this is a hack to make the pattern to be right
boolean matches = Pattern.matches(".*\\s+" + number + "\\s+.*", file);
System.out.println(matches); // => true

If your remove '1' from the file, the match will be false.Because of the spaces, it will not match '-1' and '10' int the file.

ps: because of the pattern only matches the number surrounded by spaces, if the number is in the begining of the file, and there is no space in front of the number, it will not match. So I do the hack.

split the file to array

You can split the file(also with seprator space) into array, then iterate and compare.