Need help, java.net.SocketException: socket closed

[Jess18]

I run a server and sometimes a friend gets disconnected, what does this mean and how can I fix it?

2013-12-08 18:49:42 [iNFO] [Minecraft] player1 lost connection: disconnect.quitting

2013-12-08 18:49:42 [iNFO] [sTDERR] java.net.SocketException: Socket closed

2013-12-08 18:49:42 [iNFO] [sTDOUT] Unloading Player: player1

2013-12-08 18:49:42 [iNFO] [sTDERR] at java.net.SocketOutputStream.socketWrite(Unknown Source)

2013-12-08 18:49:42 [iNFO] [sTDERR] at java.net.SocketOutputStream.write(Unknown Source)

2013-12-08 18:49:42 [iNFO] [sTDERR] at org.bouncycastle.crypto.io.CipherOutputStream.write(Unknown Source)

2013-12-08 18:49:42 [iNFO] [sTDERR] at java.io.BufferedOutputStream.flushBuffer(Unknown Source)

2013-12-08 18:49:42 [iNFO] [sTDERR] at java.io.BufferedOutputStream.flush(Unknown Source)

2013-12-08 18:49:42 [iNFO] [sTDERR] at java.io.DataOutputStream.flush(Unknown Source)

2013-12-08 18:49:42 [iNFO] [sTDERR] at ci.run(SourceFile:120)

[Jess18]

I also get this error when I stop the server, how do I fix this?

2013-12-09 02:50:07 [iNFO] [sTDERR] java.net.SocketException: socket closed

2013-12-09 02:50:07 [iNFO] [sTDERR] at java.net.DualStackPlainSocketImpl.accept0(Native Method)

2013-12-09 02:50:07 [iNFO] [sTDERR] at java.net.DualStackPlainSocketImpl.socketAccept(Unknown Source)

2013-12-09 02:50:07 [iNFO] [sTDERR] at java.net.AbstractPlainSocketImpl.accept(Unknown Source)

2013-12-09 02:50:07 [iNFO] [sTDERR] at java.net.PlainSocketImpl.accept(Unknown Source)

2013-12-09 02:50:07 [iNFO] [sTDERR] at java.net.ServerSocket.implAccept(Unknown Source)

2013-12-09 02:50:07 [iNFO] [sTDERR] at java.net.ServerSocket.accept(UnknownSource)