duration for learning JAVA for beginner

Learning a computer language, no matter what it is, for the first time always takes a long time. The language itself is actually very easy to learn and most people know the basic syntax in the first week or two. Learning how to communicate your thoughts to the computer is a long process though and will take time to get proficient at. Most first time learners confuse the libraries that are available with the actual language itself, which slows down the learning process. The libraries are built for convenience to help you, the programmer, achieve your goals, and are very similar across languages. The Java language itself is only 50 key words and a handful of syntax rules. That actually describes most computer languages. You should be able to write very simple programs in the first week or two. Within 2-5 months you should be able to start writing small programs with simple branching logic. In a year +/- you should be able to create larger simple projects. I would assume this is where your goal of "good progress in JAVA and reaching to the level of writing OOP codes" would be reached. This is highly dependent on the effort that you personally put in though. If you only study off and on then those estimates times can become a lot longer. Here is a video link I suggest all new learners watch. It is in English and is an instructor lecture for the first day of a computer science course. The speaker explains a lot of what to realistically expect for your first time learning how to program.