用于花括号的正则表达式数字Java中的花括号（{n}）

Question

I am trying to write a simple regex , but i don't know where am I going wrong . I need to check whether a string has a curly brace number curly brace.

Eg: Consider the string
Swapstream{2} - true
Swapstram - false

Pattern pattern=Pattern.compile("\\{[0-9]\\}");
Matcher matcher=pattern.matcher(input);
if(matcher.matches())
{\\logic}

Also I tried writing \\d instead of [0-9] , still the string is not matching. Please help ! . Thanks

Answer 1

You can use:

Pattern pattern=Pattern.compile("\\{\\d+\\}");
Matcher matcher=pattern.matcher(input);
if(matcher.find()) {
    /// match found
}

ie use \\d+ to allow more than one digit between { and } and more importantly use Matcher.find() instead of Matcher.matches() which expects to match complete input line.

Answer 2

The matches() method only returns true if the entire string is a match for the regular expression. You should use the find() method of the Matcher class instead.