Java Ping网站

public String PingIP(String add)    {        Runtime runtime = Runtime.getRuntime(); // 获取当前程序的运行进对象        Process process = null; // 声明处理类对象        String line = null; // 返回行信息        InputStream is = null; // 输入流        InputStreamReader isr = null; // 字节流        BufferedReader br = null;        String ip = add;        boolean res = false;// 结果        try         {            process = runtime.exec("ping " + ip); // PING            is = process.getInputStream(); // 实例化输入流            isr = new InputStreamReader(is);// 把输入流转换成字节流            br = new BufferedReader(isr);// 从字节中读取文本            while ((line = br.readLine()) != null)             {                if (line.contains("TTL"))                 {                    res = true;                    break;                }            }            is.close();            isr.close();            br.close();        }         catch (IOException e)         {            System.out.println(e);            runtime.exit(1);        }        if (res)         {            return "success";        } else         {            return "fail";        }    }