Entry: Introduction to the learning process of J2EE beginners

P.s: From the PHP project team to the Java project team, I am a beginner of J2EE. I found this article and reposted it. I hope you can spur me.

 

Java has developed into three main parts by application: j2se, j2-and J2EE. These three modules complement each other and have different application scopes.

J2se is the standard version of Java2 and is mainly used for programming desktop applications;

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.

Learn j2se first

To learn J2EE, you must first learn j2se. At the beginning, you are advised not to use IDE, and then gradually transition to using IDE for development. After all, it is convenient to use it. Learning j2se recommendations
Two books: Java2 Core Technology 1-2, Java programming thoughts, and java mode. Among them, "Java programming ideas" should be studied and intensively read. This period of time is basic learning.
It may be long or short, depending on the level of the learner.

Do not be entangled by IDE

In the process of learning Java and J2EE, you will encounter a wide variety of Ides. Don't be confused by them. When learning Java, you should learn the language, and don't care too much about the additional functions of IDE.
Yes. It is easy to convert Java programming between different ides. If you care too much about ide functions, it is easy to delay your understanding of the language. Currently, popular ides include JBuilder,
Enhanced version of wsad for eclipse and eclipse. Use one of them. We recommend that you start with eclipse J2EE. JBuilder is more suitable for writing j2se processes.
.

Select and learn server usage Configuration

When you have j2se and IDE experience, you can start learning J2EE. The web server is tomcat, which is undoubtedly the first choice for Learning Web Services. And Applications
Currently, there are three main servers: JBoss, WebLogic, and websphere. Many projects start to adopt JBoss, and a large number of companies start to do WebSphere or
WebLogic port to the JBoss Application Server (cost saving). Here we will talk about how to learn Tomcat and JBoss. I think it is the first choice and the easiest way to get started. Learning server enabling
It is best to ask experienced people with configuration (if possible), because they may solve the problem in one sentence, and it may take one or two days for you to explore the Internet on your own (I did this silly thing ), we should focus on
In terms of learning principles and theories, the use of a particular technology will never replace one's knowledge and knowledge.

Learn Web Knowledge

If you are using an e-commerce website, you may have to play several roles:

HTML, may need to use dreamwave and other ide.

Javascript, learn simple data verification, Data Association display, and so on

J2eeapi Learning

Learning j2eeapi and learning server should be an iterative process.

I want to learn JSP and Servlet programming first. There are many books in this regard. I suggest reading two articles by oreilly, JSP design and Java
Servlet programming, oreilly's book is always outstanding and I have to admire it.

To learn JDBC database programming, most J2EE projects are MIS systems, and database access is the core. This should belong to j2se learning. Here we will emphasize it.

Learn the jndi api, which can be combined with learning EJB.

Learning ejb api, recommended book "Excellent EJB"

After the above learning, we can probably deal with general applications.

Some people say that they can follow Sun's J2EE tutorial.

Learning EJB Design Patterns and viewing code (most important)

The design pattern is an internal skill, so the importance of it can be said. If you don't use the design pattern, you will write a bunch of spam that use EJB, slow and a bunch of bugs, the result is not as good as that of ejbs.
Implementation (EJB is not equal to J2EE)

No matter what language you want to learn, you should read a lot of code. If you don't have a certain amount of code, you cannot learn J2EE.

Currently, many open-source projects can be used as teaching materials:

Jive Forum

PetStore sun

Dune sun

Wait, read one and use it in your own project.

Other J2EE Learning

As you learn more about J2EE, you need to pay attention to some technical changes in the current field.

J2EE is a field of competition. Everyone puts forward their own solutions, such as structs, hiberate, OFBiz, etc.
The goal and goal are determined. It is not difficult to add them in advance, but it does not need to be too deep. After all, learning principles and theories are the most important thing.

J2eeapi

Assumerver pages (JSP) technology 1.2

Java Servlet technology 2.3

API 2.0

Java XML processing API (JAXP) 1.1

2.0 Enterprise JavaBeans Technology

Java Messaging Service (JMS) 1.0

Java Naming Directory Interface (JNDI) 1.2

Java transaction API (JTA) 1.0

Java sdk api 1.2

Javajans activation architecture (JAF) 1.0

J2EE Connector Architecture (JCA) 1.0

Java authentication and authorization Service (JAAS) 1.0

Learning some of the above APIs depends on your project. It is good to know all of them.

As mentioned above, the Java language itself is not difficult to learn, but there are too many technologies, so it is very difficult to learn Java. In retrospect, basically every beginner can
How do you know which method (API) is in which package? Haha, no other, but skilled.

 

From: http://ldj2008.blog.sohu.com/77281287.html