sin_addr is the IP address in the socket (the socket structure also contains other data, such as a port). The type of sin_addr is a union, so it can be accessed in three different ways : as s_un_b (four 1-byte integers), s_un_w (two 2-bytes integers) or as s_addr (one 4-bytes integer). inet_addr converts an IPv4 … Read more
This usually means that there was a network error, such as a TCP timeout. I would start by placing a sniffer (wireshark) on the connection to see if you can see any problems. If there is a TCP error, you should be able to see it. Also, you can check your router logs, if this … Read more
This way works well when there are multiple network interfaces. It always returns the preferred outbound IP. The destination 8.8.8.8 is not needed to be reachable. Connect on a UDP socket has the following effect: it sets the destination for Send/Recv, discards all packets from other addresses, and – which is what we use – transfers the socket … Read more
You are facing a connection breakdown. Does this happen in 3G, WiFi or “plain” connection on a computer? Anyway, you must assume that the connection may be lost from time to time, when writing your app. For example, with mobiles, this happens frequently in the tube, in basements, etc. With PC apps, this is less … Read more
This may not answer your original question, but I encountered this error and it was simply that I had not starting the server process first to listen to localhost (127.0.0.1) on the port I chose to test on. In order for the client to connect to localhost, a server must be listening on localhost.
If you have the situation where this keeps happening and killing and restarting still doesn’t work it may be a problem with your adb installation. I had to reinstall adb to resolve this problem: Reboot to ensure no instances of adb is running Launch SDK Manager in Android Studio: Tools->Android->SDK Manager Select the SDK Tools … Read more
The javadoc for SocketException states that it is Thrown to indicate that there is an error in the underlying protocol such as a TCP error In your case it seems that the connection has been closed by the server end of the connection. This could be an issue with the request you are sending or … Read more
I need to check what accounts from my huge list are still valid on VPN-server, but I haven’t found any information on how to do it with Java language. How do I connect to PPTP-server using Java? I created a socket with the server ip and PPTP-port, just like this, according to PPTP working over … Read more
I’m working with a device that sends out UDP packets on a multicast address, however I see some packets addressed to the multicast group IP with a MAC address of FFFF.FFFF.FFFF. From what I’ve read my best guess is that this is an attempt to do a network wide broadcast from the multicast group. Here’s … Read more
Yes, it is intended. Here you can read a detailed explanation. It is possible to override this behavior by setting the SO_REUSEADDR option on a socket. For example: