Many netizens asked me if I have learned Java, I said, "No, I'm only ripe." But I am very willing to write some of my experiences to learn, so that the later people will bent, help others are the biggest happiness! To learn Java, you must first know the general classification of Java. We know that since SUN has launched Java, we will try to make it out, so Java has developed to the present, and it is divided into three blocks according to application: J2SE, J2ME and J2EE, this is Sun One (Open Net Environment )system. J2se is the standard version of Java2, mainly for desktop applications. J2ME is primarily applied to embedding is system development, such as mobile phones and PDA programming; J2EE is a java2 enterprise version, mainly for distributed network programs, Such as e-commerce websites and ERP systems. J2SE development desktop application compared to VC, VB, Dephi these traditional development languages, the advantage is not obvious. J2ME For beginners, it seems to be a bit deep, and general developers have difficult to develop environments. So now the most widely used and best student is J2EE. J2EE includes many components such as JSP, Servlet, JavaBean, EJB, JDBC, Javamail, etc. It is not a one or two things to learn. So how do you learn J2EE? Of course, Java grammar first look at it first, I / O bag, util package, lang package, are you familiar? Then learn from JSP. If you have learned HTML, then things have to do more, if not, then you will make up a filling of the HTML foundation. In fact, there are not many JAVA syntax in JSP. It is more like a scripting language, a bit like ASP. Then you have learned a servlet. Servlet is a server-side applet, and he is responsible for generating an HTML file sent to the client. JSP is executed, and it is also converted to servlet and then run. Although JSP can completely replace servlet, this is also the intention of Sun launches JSP, but servlet is used to control the process jump or convenient, and the program is clearer. Next, you should learn Javabean, maybe you have long been seen whether JSP is chaotic in HTML, this way is there again? Fortunately, Sun provides JavaBean to encapsulate JAVA code in your JSP, making it easy to reuse. Then EJB, EJB is Enterprise Javabean, see the name, it is Javabean, but it is still different from JavaBean. It is an architecture that you can build safer and more stable enterprise applications. Its large number of code has been completed by middleware (which is the WebLogic, WebSphere we often listened to WebSphere, so the amount of program code we have to do is very small, most of the work is in design and configuring the middleware. As for JDBC, I don't have to say more. If you use Java to edit the database, you should be familiar. Also, if you want to send an email with Java, you have to look at JavaMail.
Then my book also look, the program is also done, others ask my question, I can solve it, is it a master? Of course, it is not so simple, this is just the first step in the Long March. Do not believe? Then you go out to pick a project, you know how to start, do you know how to design? Do you know how to organize personnel to develop? You now have some of the scattered code in your mind, there may be no other thing! What you are most lacking now is the actual work experience, rather than books that you want to come out. So you will find a Java programming work (if you can do part-time jobs in school), raise yourself in practice, that is the fastest. However, you have to pray that you encounter a master in the company, and he is willing to teach you anymore, this seems to be a bit difficult! There is also a way to read an open source program. We know that the open source is mostly from the master. They have reasonable design, considering thoughtful, coupled with the majority of programmers to participate, the value of the code is naturally the word beads, powerful (sorry, even the "gold four talents" too much). Two open source procedures for learning Java must read is Jive and Pet Store.. JIVE is a very famous BBS program, fully open source. The design of the forum has adopted many advanced technologies such as cache, user authentication, FILTER, XML, etc., and the forum fully shields access to the database, which can be easily transplanted in different databases. The forum also has a convenient installation and management procedure. This is a part that we are easily ignored when we usually program (Chinese programmers generally pay attention to the technical content of programming, but do not consider the user's feelings, this is our gap between us with foreign software The location). JIVE's information is available on many websites, you can find it. I believe that after reading the code, there will be a feeling of reborn. Unfortunately, JIVE will no longer have no conditional open source, while there is a License restriction. Fortunately, there is also a first-class Java programmer in China to pay attention to it. Foreigners do not open source, is the Chinese can't open source? Here you recommend a Chinese JIVE version -j channel. JIVE (J Dao Edition) is a famous Banq, a famous Banq, a famous Chinese Java, has adapted, and all Chinese, including some practical functions, such as map, user avatar, and user data query, and there is a development team in non-stop upgradin. You can visit Banq's website http://www.jdon.com/ to download, or go to the Tongji Technology Forum server ftp://nro.shtdu.edu.cn, what is the problem, you can go to the forum Go up asked. Pet Store. (Pet Shop) is Sun Company to demonstrate its J2EE programming specification, it should be very authoritative, and friends who want to learn J2EE and EJB don't miss it.
