提取出网页中的__VIEWSTATE

String html = "<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="jGNjNeEiiu5V3nFyg3edj77IIl5u5I54SG7m+S\" />";
Pattern pattern = Pattern.compile("id=\"__VIEWSTATE\" value=\"(\\S*)\"");
Matcher matcher = pattern.matcher(html);
if(matcher.find()){ // 这里只用了一次匹配,多次匹配用while
    System.out.println(matcher.group(0));
    System.out.println(matcher.group(1)); // 筛选出第一个括号内的内容
}

输出结果:

id="__VIEWSTATE" value="jGNjNeEiiu5V3nFyg3edj77IIl5u5I54SG7m+S"
jGNjNeEiiu5V3nFyg3edj77IIl5u5I54SG7m+S