求助java-cgi-xml


public class aa { public static void main(String[] args) {

try{
      
           URL url = new URL("http://123.com/cgi-bin/portlet.cgi?user=123&pass=456" );
       
           HttpURLConnection urlcon = (HttpURLConnection)url.openConnection();            urlcon.connect();             InputStream is = urlcon.getInputStream();
           BufferedReader buffer = new BufferedReader(new InputStreamReader(is));            StringBuffer bs = new StringBuffer();            String l = null;            while((l=buffer.readLine())!=null){                bs.append(l).append("\n");            }
           System.out.println(bs.toString());
        }catch(IOException e){            System.out.println(e);
       }
}
}
上面的代码输出一个XML格式的文本 例如下：  可是我不想全部输出，只想取一个节点的内容，例如：想取<folder name="@" disp_name="受信BOX" number="2" unread="2" size="4"/>这个节点中number="2"这个值，怎么取阿？
<?xml version="1.0" encoding="x-sjis"?>
<recent_mails>
<!-- quota-used information -->
<quota_info>
<quota>10100k</quota>
<used>8k</used>
</quota_info>
<!-- folder information -->
<folder_info current="@"> <folder name="@" disp_name="受信BOX" number="2" unread="2" size="4"/> <folder name="@.sent" disp_name="送信BOX" number="3" unread="3" size="3"/> <folder name="@.draft" disp_name="下書き" number="0" unread="0" size="0"/> <folder name="@.trash" disp_name="ごみ箱" number="0" unread="0" size="0"/> <folder name="@.spam" disp_name="迷惑メール" number="0" unread="0" size="0"/></folder_info>
<!-- mail list information -->
<mail_list folder="@"> <mail msgid="@_QR6VL3II3G" unread="1" important="0" answered="0" hasAttachedFile="0" chrono=1197448058>
<subject>システムのご紹介</subject>
<sender>admin</sender>
<date>12/12/16:27</date>
<size>3k</size>
</mail> <mail msgid="$_G125M3U377" unread="1" important="0" answered="0" hasAttachedFile="0" chrono=1197639728>
<subject>fanl_test</subject>
<sender>fanl@cybermailsolutions</sender>
<date>12/14/21:42</date>
<size>1k</size>
</mail></mail_list>
</recent_mails>