I am running jenkins using 

```
java -jar jenkins.war -httpPort=31114

```

and it starts correctly, Now I am trying to run it in background, I found it can be done using `nohup java -jar jenkins.war -httpPort=31114 &` as mentioned here [Start Jenkins in the background](https://stackoverflow.com/questions/22292612/start-jenkins-in-the-background).

But when I terminate the session I started at the beginning and try to run it in background on the same port, I get the following error:

```
SEVERE: Container startup failed
java.io.IOException: Failed to start Jetty
    at winstone.Launcher.<init>(Launcher.java:186)
    at winstone.Launcher.main(Launcher.java:354)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at Main._main(Main.java:375)
    at Main.main(Main.java:151)
Caused by: java.net.BindException: Address already in use
    at sun.nio.ch.Net.bind0(Native Method)
    at sun.nio.ch.Net.bind(Net.java:433)
    at sun.nio.ch.Net.bind(Net.java:425)
    at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
    at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
    at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:339)
    at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:307)
    at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
    at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:235)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.server.Server.doStart(Server.java:395)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at winstone.Launcher.<init>(Launcher.java:184)
    ... 7 more

```