What level of knowledge of the Java language is needed in this case (all info inside)?

Question

Java

Hi everyone. There is such a game - Korean MMORPG - Lineage 2. In this game, there are two types of assemblies - PTS (seemingly in C ++) and Java (actually in Java)

. there are (and also sold) a huge number of Java assemblies on the network and they are all different, I would like to create my own based on another one - not from scratch, of course, knowledge is not enough.

Therefore, I have a question for experienced Java developers - what level of Java proficiency is needed to be able to:
1) read the source code of the game
2) fix something for the functionality in the game
3) run your converted build.

Briefly about my "attempts" in Jave: I read Schildt, Eckel, somehow got to level 15 in Javarash. Didn't do anything serious.

Below I will attach a link to the forum where the sources of this game are posted, in which you can see everything ()

Also, a huge request to you, write me someone @ArtemIgorevich in telegram, I would like to ask a couple of questions. Of course, you do not want to do this, as compensation I can put 100 rubles into your account as payment for your time (there is no more money)

Answer 1

I started by installing a L2 server for myself and wrap everything up ... It was about 15 years ago, and now I'm a very programmer :)
Your goals described in the comments are solved by a simple server configuration. Read the information about the assembly that you have, try to figure out the structure of the server files and find the files responsible for various parameters of zones, sharpening, skills and other things. Then try to understand which code is responsible for importing and processing settings from configuration files. Do not be afraid of ANOTHER CODE WITH TERRIBLE ALGORITHMS, try to understand it, which is generally incomprehensible - write questions. Challenge accepted, and this challenge will help you later understand complex ERP systems and other enterprise applications ;)

Answer 2

Don't listen 100 percent to anyone (me too) - take the sources, it will be very cool if you manage to run them. And try.
Take a week (a month or two) to try something. Then analyze the results and think further what you need.

Answer 3

This is called "the ability to understand someone else's code", and is trained not by books, but by the practice of independent programming (to be able to think) and parsing someone else's code (to understand other people's thoughts).

Answer 4

Because there are (and also sold) a huge number of Java assemblies on the network and they are all different, I would like to create my own based on another one - not from scratch, of course, knowledge is not enough.

1) read the source code of the game

First, it is not certain that you will find an open source project. Especially paid ones are most likely to be sold in assembled form, which means that you will need to learn not only development in Java, but also reverse engineering.
When they say that the game is written in Java, but it is quite possible that in addition to the language, it was also written on the engine. For example, jMonkey, LibGDX, etc. Accordingly, you need to learn one of these engines / frameworks in order to understand how games generally work.
As you were told to read the source is one thing. Understanding what works and how it works is another.

2) fix something for the functionality in the game

Here again, if there is an open source, then everything is ok. And if the code is closed, then reverse engineering, etc.

3) run your modified build.

Here you understand that you need to be able to make games. We need a game designer, level designer, etc.
Your steps are to give up on this game for now and learn Java development, Java game development, engines and frameworks. And then it becomes clearer.