特に問題なく動いてるみたいだが
class moge {
public static void main(String[] a) {
String x = "$fax bangou 01234 tanaka.tarou $end\n$fax bangou 56789 itou.takashi $end\n$fax bangou 0123456789 tanaka.tarou $end\n$fax bangou 0123456788 itou.takashi $end\n";
hoge(x);
}
static Pattern pattern = Pattern.compile("\\$fax bangou (\\d+) \\S+ \\$end");
static void hoge(String s) {
Matcher m = pattern.matcher(s);
while(m.find()) {
System.out.println(m.group(1));
}
}
}