That's just a matter of String.contains
:
if (input.contains("{item}"))
If you need to know where it occurs, you can use indexOf
:
int index = input.indexOf("{item}");
if (index != -1) // -1 means "not found"
{
...
}
That's fine for matching exact strings - if you need real patterns (e.g. "three digits followed by at most 2 letters A-C") then you should look into regular expressions.
EDIT: Okay, it sounds like you do want regular expressions. You might want something like this:
private static final Pattern URL_PATTERN =
Pattern.compile("/\\{[a-zA-Z0-9]+\\}/");
...
if (URL_PATTERN.matches(input).find())