Data get lost when reciver offline during the conversation

when sender and receiver sharing data in b/w connection lost at receiver -end , receiver appears online to the sender during this session after that when receiver comes online the data get lost how we can handle this situation

You can either set xmpp.client.idle setting as low as possible (without making your clients reconnect sporadically) or wait till someone contributes OF-446 feature to the Openfire project.