Android - 偵測某網址是否可以正常連線 (HttpURLConnection)

如果你想要測試某個網址是否可以正常的連線，你可以使用:

int count = 0;
while (count < 5) { 
    try {
        URL myUrl = new URL("http://www.google.com");
        HttpURLConnection myConnection =
                                         (HttpURLConnection) myUrl.openConnection();
        myConnection.setConnectTimeout(5000);
        int state = myConnection.getResponseCode();
        if (state == 200) {
            Log.d("gill","the address is available!");
        }
        break;
    } catch (Exception ex) {
        count = count + 1;
    }
    Log.d("gill","the address is unavailable!");
}

getResponseCode() will return:

200 : connect normally

404 : can't connect

-1 : can't detect the result

設定setConnectTimeout(5000)表示連線5秒還沒成功就放棄。