Common problems for beginners in Java [2]: lack of basic object-oriented skills

It is reasonable to say that Java is a very OO language, and the Java Community has always been full of the "object" atmosphere. However, when I interviewed a Java programmer, I often encountered something that surprised me. I met
There are more than one job seeker who cannot even be clear about what is "polymorphism. Many people claim to have used design models, but more than half of them are limited to single-key and abstract factory models. When I thoroughly asked him/her whether the abstract factory model exists
Many people are confused about the benefits.
Why do many Java programmers lack basic object-oriented skills? It's strange that Java
Framework. Nowadays, Java's various frameworks are too developed and foolish. As a result, many programmers only need to step by step and fill in the Code according to the framework, which has basically lost OOA and OOD capabilities. Some of my Java programmers are familiar with spring, hibernate, and other frameworks. But if you give him a simple requirement, let him write an independent web framework.
Application. In the future, such developers will only become the so-called "blue-collar software", and their positions will be difficult to improve.
As in the previous post, I also raised the following questions:
★What are the differences between interface-based inheritance and implementation-based inheritance?Advantages,Disadvantages?
★What Is Inheritance (including extend and implement )?Disadvantages?
★What is polymorphism?Disadvantages?
★Why can Java inherit more interfaces than classes?
★How do you design a class structure if you want to write a game (such as a man-machine game or a five-game player?
★How do I consider scalability when designing a class structure?

If you can clarify the above issues, it means that your oo foundation is still successful. Otherwise, I suggest you look for books on OOAD and design patterns, and write simple small programs by yourself (not relying on those frameworks ), combine the learned model theory into practice. In this way, you can improve your OOAD capabilities, and the effect will be better.

Let's talk about the 3rd common faults: lack of good programming habits.

Http://program-think.blogspot.com/2009/01/defect-of-java-beginner-2-oo.html