}

public static final boolean ping() {

    String result = null;
    try {
        String ip = "www.baidu.com";// ping 的地址，可以換成任何一種可靠的外網
Process p = Runtime.getRuntime().exec("ping -c 3 -w 100 " + ip);// ping網址3次
        // 讀取ping的內容，可以不加
InputStream input = p.getInputStream();
        BufferedReader in = new 
 
BufferedReader(new InputStreamReader(input));
        StringBuffer stringBuffer = new StringBuffer();
        String content = "";
        while ((content = in.readLine()) != null) {
            stringBuffer.append(content);
        }
        Log.d("------ping-----", "result content : " + stringBuffer.toString());
        // ping的狀態
 
int status = p.waitFor();
        if (status == 0) {
            result = "success";
            return true;
        } else {
            result = "failed";
        }
    } catch (IOException e) {
        result = "IOException";
    } catch (InterruptedException e) {
        result = "InterruptedException";
    } finally {
        Log.d("----result---", "result = " + result);
    }
    return false;

}