How to quickly become a Java expert [tomjava original]

How to quickly become a Java expert [tomjava original]
Many netizens asked me if I had any shortcuts to learning java. I said, "I have no choice but to learn java ". However, I am willing to write out some of my learning experience so that later users can take less detours and help others is the greatest pleasure!

To learn java well, you must first understand the general classification of Java. We know that since Sun launched Java, it has made every effort to make it all-encompassing. Therefore, since its development, Java has been divided into three main parts by application: j2se, j2-and J2EE, this is the Sun ONE (Open Net Environment) system. J2se is the standard version of Java2 and is mainly used for programming desktop application software. j2se is mainly used for embedded system development, such as mobile phone and PDA programming. J2EE is the Enterprise Edition of Java2, it is mainly used for the development of distributed network programs, such as e-commerce websites and ERP systems.

Compared with traditional development languages such as Vc, VB, and Delphi, j2se does not seem to have obvious advantages in developing desktop applications. For beginners, it seems a bit esoteric, and it is difficult for developers to have a development environment. So J2EE is the most widely used and best to learn. J2EE includes many components, such as JSP, Servlet, JavaBean, EJB, JDBC, and javamail. It's not a day or two to learn.

So how can we learn J2EE? Of course, I/O, util, and Lang are all familiar with Java syntax? And then learn from JSP. If you have learned HTML, there are a lot of things to do. If not, you can add the HTML basics. In fact, there are not many Java syntaxes in JSP. It is more like a scripting language, a bit like ASP. Then you should learn servlet. Servlet is a server-side applet that generates HTML files sent to the client. During execution, JSP is converted to servlet before running. Although jsp can completely replace servlet in theory, this is also the intention of sun to launch JSP, but servlet is very convenient to control the process jump, it also makes the program clearer. Next, you should learn about JavaBean. Maybe you have long looked at the confusing way JSP embeds Java code in HTML. What is the difference between this method and ASP? Fortunately, Sun provides Javabean to encapsulate the Java code in your JSP to facilitate calls and reuse. The next step is EJB, and EJB is the Enterprise JavaBean. The name seems to be a JavaBean, but it is different from the JavaBean. It is an architecture where you can build safer and more stable enterprise applications. A large amount of code has been completed by middleware (also known as Weblogic and WebSphere J2EE servers), so the amount of code we need to do is small, most of the work is on designing and configuring middleware. As for JDBC, I don't need to talk about it. If you have compiled a program to access the database in Java, you should be familiar with it. Also, if you want to compile a program for sending emails in Java, you have to look at javamail.

Well, after having some basic concepts of Java and J2EE, you should compile some programs and never talk about them on paper. It is best to find some books with examples and CDs, so that you can directly Ctrl + C and then Ctrl + V to see a good program, you don't have to worry about making another mistake! There are also some good Java programming articles that need to be cut down. If you have any questions, even if the question is not too silly, the experts will answer you. The following describes several programming websites in Java:
Csdn Forum http://www.csdn.net/China's most famous Technology Forum, "programmer" magazine is they published, you can raise a question on it, someone will answer you immediately, if you feel good, you can add extra points to the person;
Java research organization http://www.javaresearch.org/There are a lot of original articles, Master is quite a lot;
Java developer http://www.chinajavaworld.com/where Java data is more comprehensive;
Java.com.cn http://www.java.com.cn/Look at this domain name will know how many cattle, registered users almost 10 thousand, and the number of online users is also around one thousand, very popular;
IBM Developer Network http://www-900.ibm.com/developerWorks/cn/java/index.shtml IBM Forever blue giant;

So I read the book and the program. I can solve all the questions asked by others. Is it true that I have become a master? Of course it is not that simple. This is only the first step after the long journey. Believe it? Then, if you go out to pick up a project, do you know how to do it, do you know how to design it, and how to organize personnel for development? There may be nothing else in your mind except some scattered code! What you lack most is actual work experience, rather than the programs created out of thin air in books. So you should find a Java programming job (if you are a student at school, you can work as a part-time employee) and improve yourself in practice, it is the fastest. But you have to pray to meet a master in the company, and he is willing to give you a hard time to teach you, it seems a little difficult!

Another way is to read the open source code program. We know that open source code is mostly from experts. They are well-designed and considerate. Coupled with the participation of a large number of programmers, the value of the Code is naturally the word, powerful (sorry, I have read more about the four talents in the gold market recently ). Two open-source programs required to learn Java are Jive and pet store.

Jive is a well-known BBS program outside China and is fully open to source code. The design of the Forum uses many advanced technologies, such as cache, user authentication, filter, and XML, and the Forum completely shields access to the database, it can be easily transplanted to different databases. The Forum also provides convenient installation and management programs, which are easily overlooked during programming. (Chinese programmers generally only focus on the technical content of programming, but do not fully consider the user experience, this is the gap between us and foreign software ). The jive information is available on many websites. You can find it for research. I believe that after you read the code, you will feel reborn. Unfortunately, since 2.5, jive has no unconditional open source code and license restrictions. Fortunately, there are still top-notch Java programmers in China who are concerned about it. If foreigners are not open-source, can Chinese people not open-source? Here we recommend a Chinese jive version-J. Jive (J-channel edition) is an adaptation of banq, a famous java community in China, based on jive 2.1. It provides all Chinese characters and some practical functions, such as textures, user profile pictures and user data query, and a development team is constantly upgrading. You can visit banq's website http://www.jdon.com/to download, or go to the Tongji Technical Forum server ftp://nro.shtdu.edu.cn to go down, what is the problem on the installation, you can go to the Forum to ask questions.

Pet Store (Pet Store) is an open source code program launched by Sun to demonstrate its J2EE programming specifications. It should be very authoritative. Do not miss it if you want to learn J2EE and EJB.

You will be happy to say, haha, it's so easy to become a Java master! I remember that tomjava also met a project manager who claimed that Java was very simple and could be learned in just three months. In fact, people who say this are just as arrogant as Japan once claimed to be "winning China in three months. It's not about tomjava. You just learned the Java skeleton, but haven't learned the essence of Java. Now you have to study the design model. The design pattern is a required course for senior programmers to truly grasp the core idea of object-oriented. The design pattern is not a specific "technology", it tells the idea, it not only shows the flexible application and wisdom of interfaces or abstract classes in actual cases, this allows you to grasp the applications of interfaces or abstract classes, so as to take a step forward from the original Java language. More importantly, the design pattern repeatedly emphasizes a purpose for you: make your program as reusable as possible.

About the design model of the information, or to recommend to everyone banq website http://www.jdon.com/, he interpret the 23 gof mode in easy to understand, pure Java description, really classic. If you have time to study the MVC structure (the design idea of separating Model-View-control), Struts is a popular implementation method, however, Struts is very complicated to use. We only need to learn its essence. We can design our own MVC structure. Then you will study software refactoring and extreme XP programming, and I believe you will go further.

After completing these steps, you may wish to organize your Java code, sort out the classic programs and common applications, and then carefully create them to improve their reusability and scalability. Let's look for some more like-minded friends to set up a studio. You can undertake some projects. It may be difficult at the beginning, but you have accumulated technical skills and have a thorough consideration, the next project can be completed quickly. I believe everyone will come to you in the future, so money is coming ......

Of course, you can also participate in some open-source projects. On the one hand, you can improve yourself, and on the other hand, you can also contribute to the Chinese software industry! Developers use cvs for cooperative development on the Internet, and use QQ, MSN, and e-mail to discuss and contact. Is it interesting that programmers from all over the world develop the same software at the same time?
The following describes two good open-source project websites:
Hubei Province software public development platform http://gro.clinux.org/
Consortium http://cosoft.org.cn/

Wow, I'm so happy that I have finally become a master! Neither. The ancients said: "The wise man is handsome ". Do you know the current development situation of the computer industry? Do you know the fight between Microsoft's. Net blueprint and Sun One Plan? Do you know where computer technology will develop? In fact, from the recent actions of major computer manufacturers, we can see that "Web services will be the commanding heights of next-generation Internet applications", while Microsoft's. net blueprint and Sun ONE plan, that is, Web services. Web Service is a brand new distributed computing model, which is a series of standard integrations (XML, SOAP, UDDI, WSDL and WSFL ). It allows software written in different languages to be easily integrated, making network resources and Web sites a service rather than a messy waste. In the near future, we will be able to click the mouse at home to complete all preparations for traveling, including flight booking, route booking, and room booking. Please note that all of this is done automatically between Web sites, and there is no need to use e-commerce as it is now. In fact, many links are manual operations. You may think this is a night talk, but it is very likely that you will undertake a project to integrate the ERP systems of two enterprises. It is very likely that the systems of upstream enterprises are compiled by Delphi, while those of downstream enterprises are compiled by Java. You said that you are a master of Java, and everyone sees how you do it. So, you have to learn new technologies, such as Web Services, and you need to know a little about Delphi (DELPHI6 now provides Web Service controls ). The Java System you compiled may be integrated with. net, so do you understand. Net? In the end, you may find that you have become a master of Java, but you have been engaged in other technologies for a lot of time. Tai chi Zhang Sanfeng said that the most amazing trick is no trick. Maybe this is the truth!

Because of the rise, there are not many web services on the Internet. I 'd like to recommend several websites to you:
China UDDI Technology Alliance http://www.uddi-china.org/
Csdn Chai Xiao road column http://www.csdn.net/develop/author/ColumnAuthor/fennivel/ (Note: Chai Xiao road is also a famous person on the Internet, he published a lot of articles about web services, but also a book, it should be referred to as the pioneer of Web Service technology in China)
Xml & Web Service columns for IBM developer networks: http://www-900.ibm.com/developerWorks/cn/xml/index.shtml? Csdn IBM is a Web Service promoter

... You have struggled to become a master of Java! Yes, it's not easy. It's not easy. It's really touching! So let me have a call. What? What is my phone number? Faint. You can call to ask if you don't know. Really ......
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