I use the following code to limit the download speed of a file in java:
package org;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
class MainClass {
public static void main(String[] args) {
download("https://speed.hetzner.de/100MB.bin");
}
public static void download(String link) {
try {
URL url = new URL(link);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setConnectTimeout(5000);
con.setReadTimeout(5000);
InputStream is = con.getInputStream();
CustomInputStream inputStream = new CustomInputStream(is);
byte[] buffer = new byte[2024];
int len;
while ((len = inputStream.read(buffer)) != -1) {
System.out.println("downloaded : " + len);
//save file
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static class CustomInputStream extends InputStream {
private static final int MAX_SPEED = 8 * 1024;
private final long ONE_SECOND = 1000;
private long downloadedWhithinOneSecond = 0L;
private long lastTime = System.currentTimeMillis();
private InputStream inputStream;
public CustomInputStream(InputStream inputStream) {
this.inputStream = inputStream;
lastTime = System.currentTimeMillis();
}
@Override
public int read() throws IOException {
long currentTime;
if (downloadedWhithinOneSecond >= MAX_SPEED
&& (((currentTime = System.currentTimeMillis()) - lastTime) < ONE_SECOND)) {
try {
Thread.sleep(ONE_SECOND - (currentTime - lastTime));
} catch (InterruptedException e) {
e.printStackTrace();
}
downloadedWhithinOneSecond = 0;
lastTime = System.currentTimeMillis();
}
int res = inputStream.read();
if (res >= 0) {
downloadedWhithinOneSecond++;
}
return res;
}
@Override
public int available() throws IOException {
return inputStream.available();
}
@Override
public void close() throws IOException {
inputStream.close();
}
}
}
The download speed is successfully limited, but a new problem arises. When the download is in progress, and I disconnect from the internet, the download does not end and continues for a while. When i disconnect the internet connection, it takes more than 10 seconds to throw a java.net.SocketTimeoutException exception. I do not really understand what happens in the background.
Why does this problem arise?
