java.lang.IllegalStateException: No match found 錯誤解決方案

執行分組捕獲之前需要先進行find()操作。   

 

         boolean b = matcher.find();
        String group = matcher.group(1);

        Pattern pattern = Pattern.compile(regex);    // 編譯正則表達式
        Matcher matcher = pattern.matcher(decoderUrl);
        boolean b = matcher.find();
        String group = matcher.group(1);