java-se - 正在学习Java SE，为什么感觉学习Java就是在学习一些API。

Question

正在学习Java SE，为什么感觉学习Java SE就是在学习一些API（目前只在少部分重要的地方学习源码）。例如Java的IO流中，就是在学习他们的各种结构关系（继承关系等），它们的构造方法，成员方法等，那要是脱离了这门语言，这些API不是相当于作废？你们学习IO流的时候是怎么学的？不知这种想法是否对？（也许各类面向对象编程语言的三大特征都是相似的：继承，封装，多态）

Answer 1

You can continue to learn Java's multi-threading, reflection, class loader, annotations, etc. These things are the tools used to build the framework structure.

(Learn IO flow, use it as soon as you get it...)

If you feel really bored, you can take a look at openJDK and study virtual machine JNI garbage collection

Answer 2

If you are interested in io flow, why not take a look at the system calls under Linux yourself. selector, epoll and the like.
Language brings you only a practical solution.

If you want to learn a language that is closer to computers, assemble. Due to the existence of object encapsulation, Java seems to be very cohesive. However, I think, at least looking at the source code, you have far more to master. For example, you see a method call, but this method is within an object. The state within the object can have a great impact on the method. But this is not so obvious in c. At least the procedural stuff can be easier to read.

Java is suitable for business. If you like pure technology, c, go, or even script shell, lua, and python are all fine.

Answer 3

1. If you think IO flow is boring, don’t read too much first, just see how to use it. That’s what I did at the beginning

2. The API can be translated, don’t memorize it by rote

3. Programming language is just a tool. Only by combining actual needs can we truly understand it

As for multi-threading, reflection, and class loaders, it is best to deliberately and in-depth study of these annotations after a certain amount of code and usage is the most efficient

In fact, learning has always been boring. What you learn in your non-comfort zone is what makes you different from others. Of course, the most important thing in the early stage is to use it~

Answer 4

Java is easy