This assumes that you have prior build knowledge or have followed the document: Customize Spark’s Look and Feel
Personally, I only changed the ones that had the 5000 ms value. I am not exactly sure what each file pertains to though, but I’ve deduced it to the best of my knowledge from the file name
Open the following files and search for “toaster.setDisplayTime” in them and change the value to your timeout
• /src/java/org/jivesoftware/spark/ui/ChatContainer.java (1 instance)
• /src/java/org/jivesoftware/sparkimpl/plugin/alerts/BroadcastPlugin.java (2 instances)
• /src/java/org/jivesoftware/sparkimpl/plugin/scratchpad/TaskNotification.java (1 instance)
• /src/java/org/jivesoftware/sparkimpl/preference/notifications/NotificationPlugi n.java (2 instances)
• /src/plugins/sip/src/java/org/jivesoftware/sparkplugin/ui/call/MissedCalls.java (1 instance)