BindException: Address already in use - With many outbound connections

Question

I have created a service that opens a lots of remote resources; for a lot, i mean over 200k / day, but i think that less than 1000 connections are opened at the same time. After i connect to the remote resource, i open an input stream to get the file content. Sometimes i get the following exception

java.net.BindException: Address already in use: connect
at java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.<init>(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.followRedirect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at java.net.HttpURLConnection.getResponseCode(Unknown Source)
at sitodove.varie.ExternalLinksChecker.getWebPage(ExternalLinksChecker.java:121)
at sitodove.varie.ExternalLinksChecker.run(ExternalLinksChecker.java:37)

This service starts correctly, opening just a few ports for limited needs because it needs to offer some services. While it is running, i get the above exception, what may be the cause?

Answer 1

A port is already being used and you try to bind it again. Check in your application if your are not trying to use a port twice.

Answer 2

Probably, you're trying to open a port that is already open. open the terminal an type telnet to see if that port is already open. ie.

telnet localhost 9889

Trying ::1...

telnet: connect to address ::1: Connection refused if this command returns Connection refused, that means the port is free.