我有一个可以使用互联网连接下载数据的应用。我使用HttpURLConnection
来做到这一点。
问题:我的应用消耗了互联网带宽,因此用户将在浏览器上慢慢浏览。我想让他们自己设置带宽限制,而不是this site。我已经知道了。
问题:如何在下载时设置带宽限制?例如:500 KB / s(每秒KiloBytes)。
以下是我下载文件的方法:
// These are the status codes.
public static final int DOWNLOADING = 0;
public static final int PAUSED = 1;
public static final int COMPLETE = 2;
public static final int CANCELLED = 3;
public static final int ERROR = 4;
private long downloaded;
private int status;
private void downloadFile(String requestUrl) throws IOException {
InputStream stream = null;
RandomAccessFile output = null;
status = DOWNLOADING;
downloaded = 0;
URL url = new URL(requestUrl);
try {
System.setProperty("http.keepAlive", "false");
output = new RandomAccessFile(my_directory, "rw");
// Open connection to URL.
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setConnectTimeout(5000);
connection.connect();
// Make sure response code is in the 200 range.
int statusCode = connection.getResponseCode();
if (statusCode != 200) {
status = ERROR;
}
stream = connection.getInputStream();
while (status == DOWNLOADING) {
byte buffer[] = new byte[1024];
// Read from server into buffer.
int read = stream.read(buffer);
if (read == -1)
break;
// Write buffer to file.
output.write(buffer, 0, read);
downloaded += read;
}
status == COMPLETE;
} catch (Exception e) {
status = ERROR;
} finally {
if (output != null) {
try {
output.close();
} catch (Exception e) {}
}
// Close connection to server.
if (stream != null) {
try {
stream.close();
} catch (Exception e) {}
}
}
}
答案 0 :(得分:1)
如果您有一个Socket
,您可以将接收缓冲区大小设置为所需的带宽延迟产品,但是,您不必在接收呼叫之间休眠。实验或一些基于反馈的算法将产生适当的睡眠间隔。
答案 1 :(得分:-1)
您可以在设置活动中使用移动数据/ Wifi /漫游中的下载等首选项。您可以使用此类获取连接类型。
/ ** *检查设备的网络连接和速度* @author Max https://stackoverflow.com/users/801646/max * * /公共课 连通性{
/** * Get the network info * @param context * @return */ public static NetworkInfo getNetworkInfo(Context context){ ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); return cm.getActiveNetworkInfo(); } /** * Check if there is any connectivity * @param context * @return */ public static boolean isConnected(Context context){ NetworkInfo info = Connectivity.getNetworkInfo(context); return (info != null && info.isConnected()); } /** * Check if there is any connectivity to a Wifi network * @param context * @param type * @return */ public static boolean isConnectedWifi(Context context){ NetworkInfo info = Connectivity.getNetworkInfo(context); return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_WIFI); } /** * Check if there is any connectivity to a mobile network * @param context * @param type * @return */ public static boolean isConnectedMobile(Context context){ NetworkInfo info = Connectivity.getNetworkInfo(context); return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_MOBILE); } /** * Check if there is fast connectivity * @param context * @return */ public static boolean isConnectedFast(Context context){ NetworkInfo info = Connectivity.getNetworkInfo(context); return (info != null && info.isConnected() && Connectivity.isConnectionFast(info.getType(),info.getSubtype())); } /** * Check if the connection is fast * @param type * @param subType * @return */ public static boolean isConnectionFast(int type, int subType){ if(type==ConnectivityManager.TYPE_WIFI){ return true; }else if(type==ConnectivityManager.TYPE_MOBILE){ switch(subType){ case TelephonyManager.NETWORK_TYPE_1xRTT: return false; // ~ 50-100 kbps case TelephonyManager.NETWORK_TYPE_CDMA: return false; // ~ 14-64 kbps case TelephonyManager.NETWORK_TYPE_EDGE: return false; // ~ 50-100 kbps case TelephonyManager.NETWORK_TYPE_EVDO_0: return true; // ~ 400-1000 kbps case TelephonyManager.NETWORK_TYPE_EVDO_A: return true; // ~ 600-1400 kbps case TelephonyManager.NETWORK_TYPE_GPRS: return false; // ~ 100 kbps case TelephonyManager.NETWORK_TYPE_HSDPA: return true; // ~ 2-14 Mbps case TelephonyManager.NETWORK_TYPE_HSPA: return true; // ~ 700-1700 kbps case TelephonyManager.NETWORK_TYPE_HSUPA: return true; // ~ 1-23 Mbps case TelephonyManager.NETWORK_TYPE_UMTS: return true; // ~ 400-7000 kbps /* * Above API level 7, make sure to set android:targetSdkVersion * to appropriate level to use these */ case TelephonyManager.NETWORK_TYPE_EHRPD: // API level 11 return true; // ~ 1-2 Mbps case TelephonyManager.NETWORK_TYPE_EVDO_B: // API level 9 return true; // ~ 5 Mbps case TelephonyManager.NETWORK_TYPE_HSPAP: // API level 13 return true; // ~ 10-20 Mbps case TelephonyManager.NETWORK_TYPE_IDEN: // API level 8 return false; // ~25 kbps case TelephonyManager.NETWORK_TYPE_LTE: // API level 11 return true; // ~ 10+ Mbps // Unknown case TelephonyManager.NETWORK_TYPE_UNKNOWN: default: return false; } }else{ return false; } }
}