Is it too much lines of code inside a class file?

Question

Hi,
I was wondering about how many lines can be considered too much in a java class file. I saw some class files with more the two thousand lines of code and even more than three thousand lines. When we have so many lines in the code I've realized that the file becomes slow for edition and it's not readable as it should be. So, as a best practice, or even due to technical issues, in average how many lines of code we'd write in order to keep the readability and avoid compile and build issues? How many lines a class should have without putting our code and performance at risk ?
thanks a lot

Answer 1

My general rule of thumb--in a class everything shold be very consistent, that is to say: you should be focusing on 1 idea in your class. IMO: If you have a class for users, you need to consistent in just what that class does. When the class becomes large, then look for related themes that run through methods of that class, and if here are many, you should make a "related class" that does satelite functions of the "core" offered in the main user class.
Thousands of lines do not a good class make, I break in to related categories of classes long before then, and as a rule I keep under 500 lines in a class--usually under 300. In any case, no more lines of code need go into a class than that to implement the core features in the main idea for that class--and no less lines of code than is needed too, don't religate a method to another class just becasue you feel it would make the class it belongs too big.
Along the idea of the user class:
Storage for the user data
Home information
Work information
physical information
tastes and preferences
family
and etc
all of these could be a class in and of themselves, but definetely are closely related to the user class.