I am building a home automation project for my Final Masters project.
If I were your professor and due to award your master's degree at some time in the near future, then I'd hate to think you'd cheated by posting my questions on an internet forum and inviting lots of folks to do your work for you. It's lazy and it doesn't deserve any reward.
Nobody knows it all. I am only asking for a hint from someone that has the experience. Please if you have any idea, please help me.
Sorry, I thought the idea of a Master's or Doctorate was that you learned to do your own research. So my advice is learn to do your own research or ask your Professor for some hints as to why you're failing to do that and how you could do it better.
Part and parcel of the whole Raspberry Pi project is to stop feeding things to consumers ready built on a plate, but to encourage folk to learn for themselves, to stop working to a script, to experiment with things they've never tried, to research things, to break things (and understand why they're broken and how to avoid that in future), to create new things by encouraging innovation.
Posting a set of three questions on a forum and asking for the boilerplate answers (that your Professor will have seen a hundred times before) does not fit that in any form at all.
I will give you one hint, forget Android, you can have a raw Java JVM running on a Raspberry Pi, but there's nothing from Android on it. With some clever programming you can have an Android client application that activates a server process that runs on a Raspberry Pi. That server process could be written in Java.