JAVA essentials-13 core specifications

Standard value:

Have you heard of this sentence? "First-class enterprises adopt standards, second-class enterprises adopt brands, and third-class enterprises adopt products !" When I was thinking, is a standard enterprise first-class? Is selling a product a three-Stream company? Even if the sales volume of a product or processing company is large, it cannot make too much money. Why?

 

Simple analysis:

 

Production is only a labor-intensive industry. It is physical labor. In this age, physical labor cannot work hard or work intelligently! This is like when all life was born, it was a blank piece of paper, and a baby grew into an adult process, but it was different, and these differences just become a different place for us and others, just like these companies, it is a process of growth from three to first-class. We should not only see the results of a company but ignore the process! He is only doing a three-stream thing, but if he has been stuck in the Three-stream thing, it is the real three-Stream company!

Second-stream companies are brand companies, such as Apple, McDonald's, and Pepsi! If a product is labeled with a certain brand, its value may be 10 times or times different? Of course, why do you trust the brand? Why can we get the trust of the masses? Who eventually raised him to a very high level? When I see this brand, I feel that it is of good quality. I think the brand company has gone through the severe test of sanstream and won the favor of consumers, today's achievements! When a company is a third-Stream company, it is ready to be a second-Stream company!

 

First-class companies adopt standards. Today, most of our operating systems are Microsoft, and most of our mobile phone systems are android, we must comply with the standards compatible with their systems when installing or making software. Otherwise, no one will buy your software. A product is made up of a brand and becomes a kind of specification. A product is so powerful that you can't leave it without it. It can be seen everywhere and can be seen everywhere, the company that makes game rules is the most powerful company. In fact, this process is also a process of continuous abstraction. At this time, the most specific product is general.

But I cannot understand the j2ee specification. Why is there j2ee13 specification? What is the role of the specification in java? Is it also a top-notch standard? We can take it and. net ,. net is a strategic product of Microsoft, and j2ee describes the product standards. Many products comply with the j2ee standards. They have their own advantages and disadvantages, but they are currently engaged in products and standards ,.. net and j2ee are not at the same level, and j2ee is more abstract.

 

Recognition Criteria:

Today, let's start by following my step to briefly understand what the 13 core standards of java's giant research are? In any case, we need to mix our faces first!

Note: I try my best to find examples in my life that correspond to everyone, but my personal abilities are limited. This is also a process. I will send some initial ideas to you for the time being. You are welcome to add them, if there is no living instance, it means I still need to study it. I will elaborate on it in my blog later!

1. JDBC (java Database Connectivity ):
JDBC APIs provide a unified way to access different databases. Just like ODBC, JDBC shields developers from some details. At the same time, JDBC access to databases is also platform-independent.

Life example: our granary is usually equipped with a Warehouse administrator. Just look for him about the warehouse. He holds the key and stores the specific data of each warehouse!


2. JNDI (Java Name and Directory Interface ):
The jndi api is used to run the name and directory services. It provides consistent models for accessing and operating enterprise-level resources such as DNS and LDAP, local file systems, or objects on application servers.

Examples of life: roster or genealogy. Each of us was born to register a name in the genealogy so that we can know the ins and outs of this person by name!


3. EJB (Enterprise JavaBean ):
One of the reasons why J2ee technology has won wide attention is that EJB provides a framework for developing and implementing distributed business logic, which significantly simplifies enterprise-level application development with scalability and high complexity. The EJB specification defines how the EJB components interact with their containers. Containers are responsible for providing public services, such as directory services, transaction management, security, resource buffer pools, and fault tolerance. However, it should be noted that EJB is not the only way for J2EE. It is precisely because of the openness of EJB that some vendors can achieve the same purpose in parallel with EJB.

Example: What is EJB ...... I understand for the time being that it is a special class. In particular, it can implement distributed services, that is, multiple people can do one thing at the same time. In short, there is a little dizzy!

4. RMI (RemoteMethod Invoke): remote (remote) invoke (CALL ):
As its name indicates, the RMI protocol calls methods on remote objects. It uses serialization to transmit data on the client and server. RMI is a more underlying protocol used by EJB.


5. Java IDL (Interface Definition Language)/CORBA: Common Object Request Breaker Architecture ):
With the support of java IDL, developers can integrate Java and CORBA. They can create Java objects and enable them to expand in corba orb, or they can create Java classes and serve as the client of the CORBA object that is expanded with other ORB. The latter method provides another way to integrate your new application with the old system.


6. JSP (Java Server Pages ):
A Jsp page consists of html code and new Java code embedded in it. The server processes the java code after the page is requested by the client, and then returns the generated html page to the browser of the client.


7. Java Servlet:
Servlet is a small java program that extends the functions of web servers. As a server-side application, it is executed when requested, which is similar to CGI Perl script. Most of the functions provided by Servlet are similar to those provided by jsp, but the implementation methods are different. JSP embeds a small amount of java code in most html code, while servlets are all written in java and generate the corresponding html.


8. XML (Extensible Markup Language ):
XML is a language that can be used to define other Markup languages. It is used to share data in different business processes. The development of XML and Java are independent from each other. However, it has the same objective as java and is exactly platform independent. Through the combination of java and xml, we can get a perfect solution with platform independence.
Examples of life: We have a rule on how to say this code. As long as you are the person in this stockade, we have a set of codes, which are mainly used to transmit information!

9. JMS (Java Message Service ):
Ms is an application interface (API) used to communicate with message-oriented middleware ). It supports point-to-point domains, publishing/subscription domains, and supports the following types: Approved message transmission, transactional message transmission, supports consistent messages and persistent subscribers. JMS also provides another way to integrate your application with the old background system.


10. JTA (Java Transaction Architecture ):
JTA defines a standard API that allows the application system to access various transaction monitors.


11. JTS (Java Transaction Service ):
JTS is the basic implementation of corba ots transaction monitoring. JTS specifies the implementation method of the Transaction Manager. The Transaction manager is a Java image that supports the java Transaction API (JTA) specification at the high-level level and implements omg ots specification at a lower level. JTS Transaction Manager provides transaction services for application servers, resource managers, independent applications, and communication resource managers.


12. JavaMail:
JavaMail is an API used to access the mail service. It provides a set of abstract classes for the mail server. Not only supports SMTP servers, but also supports IMAP servers.

Examples of life: it can be understood as the post office. We fill in the address, the Post Office is responsible for all the rest, and we pack the mail!


13. JAF (JavaBeans Activation Framework ):
JavaMail uses JAF to process MIME-encoded email attachments. MIME byte streams can be converted to java objects or to Java objects. Most applications do not need to use JAF directly.

 

 

Summary:

In our real life, the export is full of standards, the building has building standards, the chefs are qualified to authenticate, the English has an ielts toefl, and the seeds in the ground have a yield, which is not invented by anyone, with our social progress, our experience has improved, and our knowledge has been further clarified. in JAVA, JAVA standards are also a collection of experiences, it's just the application of various examples in life to computer technology!