Isso pode ser configurado definindo o "maxIdleTime" no conector do soquete. Veja Configurando Conectores
Por exemplo, em jetty.xml
<Call name="addConnector">
<Arg>
<New class="org.mortbay.jetty.nio.SelectChannelConnector">
<Set name="maxIdleTime">10000</Set>
Do manual:
Set the maximum Idle time for a connection, which roughly translates to the Socket.setSoTimeout(int) call, although with NIO implementations other mechanisms may be used to implement the timeout.