Java RegEx 找不到匹配错误

Question

下面的正则表达式给我 java.lang.IllegalStateException: No match found 错误

String requestpattern = "^[A-Za-z]+ \\/+(\\w+)";
Pattern p = Pattern.compile(requestpattern);
Matcher matcher = p.matcher(requeststring);
return matcher.group(1);

请求字符串在哪里

POST //upload/sendData.htm HTTP/1.1

如有任何帮助，我们将不胜感激。

Answer 1

未尝试匹配。在调用 group() 之前调用 find()。

public static void main(String[] args) {
    String requeststring = "POST //upload/sendData.htm HTTP/1.1";
    String requestpattern = "^[A-Za-z]+ \\/+(\\w+)";
    Pattern p = Pattern.compile(requestpattern);
    Matcher matcher = p.matcher(requeststring);
    System.out.println(matcher.find());
    System.out.println(matcher.group(1));
}

输出:

true
upload