Core JAVA Application fixes

We just build an application in JAVA for our personal use but the developer quit the job in middle and now we have an unfinished application. We need someone to help us in completing it. Only a few things are remaining. I'll share the exact details but to complete it you must know how to do the following things in core JAVA 1) Auto Complete text box to fetch from database 2) Pop up boxes in an application 3) The database for this application will be online but in case internet is down we want it to be stored into a txt file and then exported to the online database as soon as the connectivity is back on. MOST IMP THING: after exporting to the cloud the text file should be empty... mainly we dont want anything from our database to be in our system. 4) How to work with printing a receipt based on certain criteria i.e one will be internal and one will be external.... internal will be divided in categories. If u know how to do all of the above in core java than you could be the perfect fit. Attached is a description. Highlighted fields are remaining to be completed.