Java Engineers Study Guide
Beginners
Recently, many small partners to ask me how Java White started, learn how to arrange the line, every step should be how to get better. Originally I thought the previous articles we may have solved the problem, it is not true, because I wrote the previous article are standing on the back-end of the global Java reflection and summary, ignoring a lot of the white are the feelings, and many of my friends need to be more basic, more detailed study of the route.
So, today we re-open a new topic, were about Java learning path according to four articles (namely the entry papers, primary articles, intermediate articles, advanced part), I also intend to take this opportunity to recall their own learning Java course. Today we talk about is how White students Started Java.
Declare that the contents of the article does not detail how to operate each step, it will only provide general ideas and direction for everyone to inspire, if you really want to guide the operator step by step, then the thickness of a book that requires at least friends.
The methods described herein are not necessarily for everyone, if wrong please understand.
01
initial preparation work
Development environment to build
This step we tend to skip, but since it is for the white of course, mention it here. First you need a computer, and then install the JDK and JRE, JDK provides the Java development tools, that is, some necessary jar package, JRE is the Java runtime environment components, we are familiar with the JVM in there.
After installing these two Dongdong, the general also configure the environment variable, otherwise there are some directories may not be found correctly.
IDE select and install
IDE refers to local development editor, without it, you can only knock code directly in Notepad such tools in the. IDE biggest advantage is the integration of a large number of tools and features modules allow you to very easily complete the development.
Before we all use eclipse, but the eclipse is already out of fashion, and now I recommend you use intellij idea as your first code editor directly. If students eclipse is used, it may be substantially painless switch.
intellij idea can be downloaded directly on the official website trial version for 30 days, if you want to permanently use the Internet, there are some ways to drop.
About jar package
What jar package is, in fact, a bunch of class will be packaged format files, Java jar in it called packages, these jar package in the compiler can be identified directly, allowing developers to use.
For the uninitiated, it may only need to use some API JDK comes, but if you want to refer to external jar package, might encounter some difficult. For idea, the introduced external jar package there are two ways, one is manually introduced jar package, one is to use maven. Let's talk about who will be in Java Web related articles.
Manual import jar package actually not difficult, you need to download a good jar package, and then select the package to import the jar under the corresponding item, specific methods do not start here say, because can find it online.
Java-based learning in several ways
Learn basic grammar
Learning a language, things are beginning to do is to learn its grammar. I was first learning Java syntax in Runoob, this site allows you to any one language to complete the fastest entry syntax, of course, this is only the equivalent of your browser again basic grammar.
To truly grasp the Java language foundation, just look at basic grammar is not enough, my first contact with Java courses in junior, listening to the teacher talk about the three characteristics of object-oriented heard at a loss, even arrays are initialized reason not clear, but these elements are what we need to know. Therefore, in order to learn the basics of Java, we need to look at the video or read a book to learn.
Watch the video
Video, you can admire the geeky college or listen Java class network foundation course, of course, I can see the video sharing Java programs. We all know that Java is training very much, basically things to learn are also similar, but they are some of the courses is also good, we have a channel, then you can go take a look.
See the benefits of video is that you can receive a better knowledge, but also cost you more practice, so sometimes you can also choose to read.
Reading
Read a book, then, it is not recommended for white too complicated book, such as "Java programming ideas" of this book, and newcomers do not see. Personally, I recommend that you only need to first look at "Java Mastering" This type of book is sufficient, because this part of the study is just off the ground behind you learn, you may later have to go back and re-examine these content.
Now available on Java-based books too much, uneven quality, content homogeneity, in fact, not many I've seen. Give us a suggestion, you only need to pick a book or two to look at, here we recommend two of the most simple of it, "head first java" and "Java from entry to the master."
Look blog
Here then recommend another way to learn is to see the blog, blog than books, it is more suitable for learning a technical point, you can easily find the relevant principles of this knowledge on the Internet, implementation, and code example.
My blog there is not anything to explain the basis of the special, if you look at some of the more basic articles to be viewed on Runoob and other sites. If you have a very clear knowledge want to learn, I believe Soso engine will give you a better answer.
Practice Code
In addition, the general Java books or video course will require you to complete some appropriate exercises, you need to own this part using the IDE to complete in the computer.
In the IDE, you can be well familiar with the Java language, basic code, and can try a variety of API, and tested a number of language features, such as inheritance, encapsulation, polymorphism, and so on.
In addition, this is also a good chance you are familiar with the IDE, because in the company to do development IDE may take a variety of functions, know in advance the good IDE is definitely useful.
Java entry required knowledge carding
In the Java entry stage, you may need to access this part of the knowledge around, but the focus when you are no matter which way by learning from, the content you are learning the basics of Java.
Java Basics
This part is you have to master the content, in the introductory stage you need to play them a solid foundation in order to be better in the back of the learning content.
How to play solid foundation of it, the best way is in each case on the IDE on the book or on the video have achieved it again, of course, sometimes you can also write your own some interesting examples.
1 basic data types
For example int, double, char, and their packaging.
Familiar with the basic data types used to understand the number of bytes occupied by each type, and the conversion between them and the packaging.
2 Process Control
For example, for circulation, if else, while circulation and so on
If the students have learned c language, you can skip this part.
String in string type 3
Java string type is a very important type, it is not the basic data types, but very common, familiar and practical String related api, you begin to learn to string it.
4 Array
Initialize an array of ways which, how should write two-dimensional array, the array as a method parameter how should you deal with?
5 classes and objects
Java is the most important two concepts: classes and objects, they have what use is it, what is the difference and touch it, please practice them in your code it.
Java core technology
For this part, I believe that many white only understand their basic use, but does not understand some of the principles behind it: for example, why there are interfaces and abstract classes these differences, what is the point polymorphism is why there must be reflection .
Novice when learning this part, just you need to know how to use it. Of course, you'd better put these properties are achieved again, to deepen the impression.
As for why these characteristics, what is the principle behind these features is that the content is not what we are talking about, we will tell them the contents of the articles in primary and secondary. Because, to understand these principles, you have to understand JVM, understand the basis of concurrent technology to understand the network infrastructure even more. Obviously, this is not something you can do now.
1 abstract classes and interfaces
Write some interfaces, and write some implementation class to implement these interfaces, and find out why we need an interface, why subclasses need to implement the interface in the method.
Similarly, to achieve some abstract class bar. Then take a look at it any different interfaces.
2 inheritance, polymorphism and encapsulation
How to Understand What is the connection between inheritance, the parent class and subclass of it.
Encapsulation is a way to protect the code, there are ways in which it can be achieved package.
Overloading and polymorphism are generally divided into rewriting, which are how to use?
3 Exception Handling
Java Exception handling is mainly used for capturing and processing errors, you write some try catch block to catch the error bars.
4 collections
The collection is something we often need to deal with, List, Map, Set, and so, as soon as possible to become familiar with API, then write some tests you an example.
5 IO input and output streams
IO input and output streams can manipulate the contents of documents, data and other networks, how to complete such a complex operation in Java code does, in fact, only a few simple api on it.
6 Multi-threading
In order to make the most rational system of resource allocation and scheduling, we need multi-threaded, multi-threaded program will make it fun, it will bring a lot of problems, use the Thread and related API, try these interesting things right.
Optional content:
1 reflection (to understand, not entry must)
2 enumerated types and generics (can understand, not entry must)
Communication network 3 (socket used to understand the basic, required network infrastructure)
4 database operations (JDBC can understand the basic need database infrastructure)
to sum up
All in all, for a white Java, the Java entry can be divided into these steps:
1 First, build a good Java development environment
2 familiar with Java and some other sites by Runoob basic grammar
3 familiar with the basics of Java by reading to see a video, etc., to deepen understanding through code practice
4 By reading to see a video, etc. preliminary understanding of the core Java technology, deepen understanding through code practice.
This article is for everyone to provide a study of ideas, and recommend some learning methods, if you can learn to follow such a step, and with some for your own learning methods to complete the study program, I believe you can be well completed Java entry.