The veteran driver who has been playing Java for many years will take you on the car to learn Java comprehensively, and can also teach you how to learn to get a good offer this year .
Speaking of the comprehensive system , it is based on the knowledge content required by most companies at present . After all, we learn Java for high-paying jobs. The "Historical Records" says that "the world is full of benefits, and the world's hustle and bustle is for profit." Going to ", learning Java technology for high-paying jobs is human nature, and it is also the goal of most people's struggle.
Let’s take a look at what skills are needed to recruit Java programmers in the market:
Everyone has looked at the recruitment requirements of the above three companies and found that the current requirements for junior Java engineers are similar, and the main frameworks are SpringMVC , Mybatis , SpringBoot , and SpringCloud . The database is MySQL and Oracle . Generally, small and medium-sized companies use MySQL, while slightly larger companies are mainly Oracle, as well as web-related basic content and the use of tools such as git , Maven , and SVN .
Therefore, we must first understand what technology needs to be learned in the current market. The knowledge you have learned must be useful and keep up with the forefront of the times. The so-called comprehensive and systematic learning of Java, we must first understand what we should learn.
The Java content of the comprehensive system is as follows:
One, JavaSE basic articles
JavaSE is a standard version, which is the basic part of the Java language. Various frameworks derived from Java (such as the Spring series) and various products are based on the JavaSE standard. JavaSE is the foundation for the upward development of Java and the underlying foundation for any advanced Java product. It's all JavaSE, which is generally the "daddy" of all children. If you don't learn JavaSE well and don't understand it thoroughly, it will be like a book when you learn the framework later, so the importance of this part of JavaSE is self-evident, and I hope you will remember it.
Mainly include content: data types, basic grammar, operators, process control, arrays, object-oriented, common classes, exception handling, collections, IO streams, multithreading, reflection, annotation, analysis, network programming.
Recommended learning tutorial: 2020 Java zero-based introductory basic tutorial
PS: The content of JavaSE is very large. Any set of JavaSE tutorials will not cover all the methods, but will only choose the content commonly used in daily work to explain, so many of the content in JavaSE is in the API documentation after class. Slowly understand, you must learn to learn actively, and you can't just sit back and wait.
Recommended learning books: Java core technology
This book was written by Lao Mei. Since its publication, it has been favored by the majority of Java programmers. It has been selling well and is a classic Java book. Covers all the basic knowledge of the Java Platform Standard Edition JavaSE, provides a large number of complete and practical application examples, and introduces the basic knowledge of the Java language, object-oriented programming, interfaces and internal classes, event listener model, and swing graphical users in detail. Interface programming, packaged applications, exception handling, login and debugging, generic programming, collection framework, multithreading, etc. ( This book is a must-read book for every Java programmer )
Two, database articles
Database is a must-learn content for learning Java language. Common databases are MySQL and Oracle . As beginners, they usually learn MySQL. Under normal circumstances, small and medium-sized enterprises will choose MySQL database. Larger Internet companies I will choose to use Oracle, and learning Oracle is more complicated than MySQL. It is recommended that you mainly learn MySQL database, and Oracle can be used as an understanding. Learning the database is relatively simple, the basic operation is to add, delete, modify and check.
Three, web development
Web front-end content: HTML/CSS/JavaScript/ (front-end page)
Note: Java back-end development does not need to pay too much attention to the processing of HTML pages and CSS, but at least it must be able to use simple HTML. JavaScript is a must, because Javaweb back-end programmers need to be exposed to the use of AJAX to process data and display. Of course, if you only focus on server-side implementation without considering any user interface, you don’t need to focus on HTML, CSS, and JavaScript. However, although there are many developments that are completely separated from the front-end, it is impossible to not care about the front-end, especially JavaScript, but The front end can be completely ignorant of any implementation of the server backend.
Recommended study books: "JavaScript DOM Programming Art" (Second Edition)
This book makes sense as the most recommended front-end introductory book. He can really let everyone understand dom script programming, or the ideas and principles behind front-end programming technology. For beginners, this book does not have any threshold, just follow the book example to write code step by step. We will know how to operate and control browser elements, and will learn how to achieve simple page effects. This simple and easy sense of accomplishment is the most valuable experience when starting a programming language.
JavaEE内容：Servlet/JSP
Although JSP is rarely used on the Internet now, it may be replaced by some templates or JS AJAX methods, but I think it should be contacted, if it is necessary to use it, it will not do anything, and it is a dynamic web page of Java EE Implement standard components. Learning the JSP process can also help us better understand the process of web sessions, and master what we need to know about web sessions. If you learn Javaweb and JSP without contacting it, it is equivalent to learning to use Springboot without contacting SpringFramework at all. Wouldn't it be silly. Including the concepts that we must know to develop Javaweb, such as Web application context, request object, response object, HttpSession, Cookie, etc. are all embodied in the contact learning JSP and Servelt, as well as some relatively rare EJB JSF JMS and Java Felix.
Some beginners are not clear about these inevitably and there will be misunderstandings, especially some more mature engineers say the same, I can only say that they are very ignorant, just code machines, in fact, they are confused about application development and design.
There is no technology that will never be eliminated and there is no universal technology that will always be popular. It depends on the environment and application. The technology and tools that meet my needs are good and right.
Four, high-level framework
1. Springframework core IOC container
2. Spring boot is a more comprehensive Spring tool based on Spring to improve efficiency
3. The most popular ORM frameworks today are Mybatis and MP (Mybatis plug-in), Hibernate is optional for learning
4. Template technology, relatively mature Freemarker
5. Spring Cloud microservice framework, a full set of distributed system solutions provided by Spring Cloud.
Five, tools
Maven is a tool for constructing and managing projects, while svn and git are project source code and related documentation management tools developed by teams. Learners need to master their applications.
Tomcat, jetty, resin, JBoss, GlassFish, etc. are all servers that deploy and run Java web applications.
The above is the content that beginners probably learn. I try to stand from the perspective of beginners. It is not particularly complicated. I am afraid that the beginners will not understand it and there is no substantial help. So I try to use the vernacular to make it simpler, and list the main Java knowledge points for everyone.
Knowing the general content of Java to learn, the following is how to learn Java in the best way, so as to achieve the level of employment. First, we should understand what it is like to achieve the level of finding a job.
To what extent can Java learn to reach the level of employment:
For most students who are new to Java, what I am most concerned about is what I have to learn and to what extent I can find relevant Java R&D jobs.
Different software companies have different requirements for the level of R&D personnel. If from the perspective of most small and medium-sized enterprises, an IT technician who can enter the company usually needs to have the following capabilities.
1 Understand and master Java's core object-oriented design ideas and code construction, and be able to design and write business functions in an object-oriented manner;
2 Proficiency in the development of at least two databases, such as Oracle, mySql, and proficient in writing basic and advanced SQL statements;
3 Must master and proficiently apply the Springframework IOC container, deeply understand and apply the concepts of IOC and AOP, and use MVC to realize the processing of web requests;
4 Familiar with the ORM framework myBatis and JDBCTemplate, which are used in Java to process the database, should also have an understanding of Hibernate;
5 Proficiency in applying Spring boot, a collection of Spring enhancement tools;
6 At least proficient in using Eclipse and IDEA integrated development tools to build applications;
7 Able to basically master the use of MVN GIT Maven in the project;
8 Front-end development must master JavaScript and commonly used JS frameworks
The above are the basic requirements for entry of small and medium software companies. If you can reach this level, it should not be difficult to find a Java job.
Recommended learning method: system video tutorial + book assistance + human guidance
Video tutorials: For Java beginners, watching videos is also the most common way to learn. Video tutorials will explain the knowledge commonly used in work, and the videos are generally divided into chapters and sections, and each section only talks about one knowledge point. , It is clearer to learn. But the video tutorial should be as complete as possible, preferably a complete set of video learning.
Book assistance: Books are convenient for supplementing theoretical knowledge, so that it is easier to understand Java's object-oriented core design concepts and code practice functions.
PS: But most people don't have the patience to read the book, so most people just watch video tutorials to learn. If you can see, just watch, if you can't, don't watch.
Someone’s guidance : Most people can’t learn Java very well by their own ability, because you don’t know the industry or how to learn it. If you want to find a job by self-learning Java with zero basis, the probability is extremely low. Therefore, it is recommended that if you really want to do this, try to find someone to take you with you. If you don’t understand, you can ask directly, avoid detours, and improve efficiency. The quality of learning determines the salary and starting point of future work, so it should be taken seriously.
Importance of the project
Many Java beginners have watched some videos and said they "will" after learning for a while. Here I need to correct a problem for everyone. I hope that everyone who learns Java can clearly know what the center of learning programming is. In fact, in my opinion, there has never been such a saying about learning to program. Learning programming is different from mathematics, physics, and chemistry in junior high school. Remember some formulas and do the same type of exercises to prove that you can do similar types of problems. Programming only talks about the level and level of technical ability. What can best prove the stage of technical ability is that in the process of doing the project, the quality of the developed Internet products, the quality of the code written, and the troubleshooting ability , How about the ability to find bugs, how about the ability to conceive the overall layout of functional modules, and so on. If you want to reach the entry level as a beginner, you have to have the coding ability of some simple projects. The most important thing for a beginner is to cultivate your own programming thinking. Every program is different, and you can't memorize it all. , Learning programming does not rely on rote memorization. Only when you can code and write something independently can you get a job.
Therefore, the ability to do projects can be used to measure the level of learning at which stage, and often those who say "will" often have not written much code, and they can't do a project. This is just talking on paper and completely misinterpreting it. I don’t know what I’m learning to learn programming, and I don’t know where I should go.
Therefore, in the overall process of learning, a Java beginner must have two projects that can be obtained and can be written on the resume as capital for finding a job, and must have a good understanding of the ins and outs of these two projects. Maybe the interview is successful at the end. After learning all the content of Java, if a beginner is not up to the level that can do simple projects, then his entire learning process is in vain. If the final learning goal is not reached, the quality of learning is not good. So the importance of the project I hope everyone is clear, because there are too many Java beginners who don't know what the purpose of the final learning is, and finally waste time in vain.
Learning mentality:
Learning to program is definitely not a simple task. In other words, it is still quite difficult. After all, it is possible to go out and find a job, which can range from five to six thousand to tens of thousands of jobs. None of these knowledge is casual or anyone can learn. Regarding this learning mentality, I hope to remind everyone to focus on "learning", because I found that many Java beginners learn like " complete tasks ". The so-called task completion is " I watch these videos Will I be able to find a job when I finish it? ” “ Can I find a job after I have learned all this? ” Learning is not the same as “ learning ”. These are two different concepts.
Did you understand it?
Can you apply it?
Are you paying attention?
You should be the clearest. I found that those who treat learning as completing tasks are not patient. They deceive themselves into " I can find a job after watching these videos. " In the end, I gradually understood that I was deceiving myself and others, and finally gave up saying that I was not suitable for learning this. In fact, there is only one truth in unmasking these people: they do not have the patience to study, and they do not like to learn. This is caused by previous experience and caused by many years of habit.
Therefore, the correct learning mentality must focus on the learning itself . You have to learn this knowledge, these contents, and these technologies, which need to be gradually accumulated day by day, and no results can be achieved in a short time.
PS: If you have no patience and interest in learning, I advise you not to learn programming. Learning programming is definitely a patient job, and it is an industry that requires continuous learning and charging. In other words, in the information age, people who don’t like to learn and those who have the patience to learn knowledge can’t get along in the information age. This is true in any industry. Those who don’t learn, progress, and stay close to the times must Will be eliminated.
In the end, those who can get a job by self-study Java basically have the following points:
1. Have a strong learning patience and enterprising spirit
2. Don't be lazy, write enough code, practice makes perfect
3. Have a certain learning ability, be good at self-study and be good at solving problems by yourself
4. You can write some simple projects independently
The above content is written by myself. From the point of view of Java beginners, I hope that you can use easy-to-understand language to make everyone clearly understand the learning content of a comprehensive Java system and to what degree you should get it. An offer for a Java job, I hope it can be helpful to everyone.
At last
If you want to learn Java, I will share some Java learning materials with you. You don’t have to waste time searching everywhere. I have compiled all the materials from Java entry to proficiency. There are 6000G in total. These materials are all made by me. Java’s latest Java learning routes compiled in recent years, Java written test questions, Java interview questions, Java zero-based to proficient video courses, Java development tools, Java practice projects, Java e-books, Java study notes, PDF document tutorials, Java programmers Face-to-face, Java job application resume templates, etc., these materials will definitely bring you a great help in learning Java in the next. Every Java beginner must have it. Please enter my Java technology QQ exchange group: 127522921 to download by yourself. All the information is in the group file, so you need to communicate and learn more with you when you go in.