What is the EE (i.)

1. The concept of the Java EE

Currently, there are 3 versions of the Java 2 platform, which are Java 2 platform Micro (Java 2 Platform micro Edition,j2me) for small devices and smart cards, and Java 2 Platform Standard Edition for desktop systems (Java 2 Platform Standard EDITION,J2SE), Java 2 Platform Enterprise Edition (Java 2 Platform Enterprise EDITION,J2EE) for creating server applications and services.

EE is an architecture that leverages the Java 2 platform to simplify the development, deployment, and management of enterprise solutions related to complex issues. Based on the core Java platform or the standard version of the Java 2 platform, the EE technology consolidates many of the benefits of the Standard Edition, such as the "write once, run Anywhere" feature, the JDBC API for easy access to the database, CORBA technology and security patterns that protect data in Internet applications, and so on, as well as the EJB (Enterprise JavaBeans), Java servlets API, JSP (Java Server Pages) and full support for XML technology. The ultimate goal is to be an architecture that enables enterprise developers to dramatically reduce time-to-market.

The Java EE architecture provides a middle-tier integration framework to meet the needs of applications that require high availability, high reliability, and scalability without too much expense. By providing a unified development platform, Java EE reduces the cost and complexity of developing multi-tiered applications, while providing strong support for existing application integration, full support for Enterprise JavaBeans, good Wizard support for packaging and deploying applications, adding directory support, enhanced security, Improved performance.

PS:2EE is all called Java2 Platform Enterprise Edition. "The EE platform is essentially a distributed server application design environment-a Java environment that provides a running infrastructure environment for host applications and a set of Java extension APIs to create applications." ”

2. Java and EE

With the rapid development of Internet network, enterprise application based on Internet requires the software platform to be open, distributed and platform-Independent. So there are rpc/com/corba and other technologies, but there are many deficiencies and limitations in the practical application of these technologies. Their specific protocols are difficult to pass through firewalls and are therefore not suitable for application development on the Web. To further develop web-based applications, Sun's sun
One (Open NET Environment Development network environment) and Microsoft Corporation's. NET Web Services technology architecture.

Sun
The one architecture is centered on the Java language, including J2se/j2ee/j2me and a range of standards, technologies, and protocols. It includes Sun's exclusive iplanet software family, which has the most popular LDAP directory server software on the market, as well as forte
For java--software tools that facilitate the writing of the Java language in any environment. We can easily access and use it from the Internet for free, including Java
Products such as the integrated development environment, Java Database and middleware (application server) servers, and their source code. Sun
One is closer to or able to meet the requirements of the Internet for distributed, developmental, and platform-agnostic aspects of intelligent Web services.

With the development of Java technology, it is further subdivided according to the market: Java 2 Enterprise
Edition), J2SE for common PC applications (Java 2 standard
Edition) and three versions of J2ME (Java 2 Micro Edition) for embedded devices and consumer appliances. This article on Sun
The Java core application of one--J2SE/J2EE/J2ME for some introductions.

Advantages of 3.J2EE

The Java EE provides a good mechanism for building a business system with scalability, flexibility and serviceability.

• Keep your existing IT assets

As businesses have to adapt to new business needs, it is important to take advantage of existing investment in enterprise information systems rather than to re-establish a holistic approach. Thus, a server-side platform mechanism built on existing systems in a gradual (rather than radical, totally negated) manner is required by the company. The Java EE architecture can take full advantage of the user's original investments, such as Bea Tuxedo, IBM CICS, IBM Encina, Inprise Visibroker, and Netscape application Server used by some companies. This is possible because Java EE has extensive industry support and a number of important ' enterprise computing ' domain vendors involved. Each supplier provides an upgrade path to existing customers to move into the portable Java EE domain without having to scrap already invested. Because the Java EE platform-based product can operate on virtually any operating system and hardware configuration, the existing operating system and hardware can also be reserved for use.

• High-efficiency development

The Java EE allows the company to hand over some of the common, cumbersome service-side tasks to the middleware vendors to complete. This allows developers to focus on how to create business logic, which reduces development time accordingly. Advanced middleware vendors provide these complex middleware services:
State Management Services – get developers to write less code and not care about how to manage state so that program development can be done faster.
Continuous service – Enabling developers to write applications without coding their data access logic to generate lighter, database-independent applications that are easier to develop and maintain.
Distributed shared data Object Cache service – enables developers to develop high-performance systems that greatly increase the scalability of the overall deployment.

• Supports heterogeneous environments:

Java EE can develop portable programs that are deployed in heterogeneous environments. The Java EE-based application does not rely on any specific operating system, middleware, hardware. Therefore, a well-designed Java EE-based program can be deployed to a variety of platforms in just one development. This is critical in a typical heterogeneous enterprise computing environment. The Java EE Standard also allows customers to order out-of-the-box components that are compatible with Java EE, deploy them to heterogeneous environments, and save the cost of developing their own entire program.

• Scalability

Enterprises must choose a server-side platform that provides excellent scalability to meet the large number of new customers who are doing business on their systems. Applications based on the Java EE platform can be deployed on a variety of operating systems. For example, it can be deployed to high-end UNIX and mainframe systems, which can support 64 to 256 processors in a single machine. (This is what the NT Server has to offer) the Java EE domain provides a broader load-balancing strategy for vendors. Eliminates bottlenecks in the system, allowing multiple servers to be integrated with deployment. This deployment can reach up to thousands of processors, enabling highly scalable systems to meet the needs of future commercial applications.

• Stable availability

A server-side platform must be able to operate 24x7 to meet the needs of our customers and partners. Because the internet is globalized and ubiquitous, it can cause serious losses even at night as planned. If unplanned downtime, it can have disastrous consequences. Java EE is deployed in a reliable operating environment, and they support long-term availability. Some Java EE is deployed in a Windows environment, and customers can choose a more robust operating system such as Sun Solaris, IBM os/390. The most robust operating system can reach 99.999% availability or just 5 minutes of downtime per year. This is the ideal choice for real-time business systems.

Summarize

The Java EE is a completely different technology architecture from traditional application development, including many components that simplify and standardize the development and deployment of application systems, thus improving portability, security, and reuse value.

Java EE Core is a set of technical specifications and guidelines, including various types of components, service architecture and technical level, all have common standards and specifications, so that the different platforms following the Java EE architecture, there is good compatibility, to solve the past enterprise backend use of information products are incompatible with each other, The dilemma that makes it difficult for companies to communicate internally or externally.
This article briefly introduces some basic knowledge of the Java EE, and next time we will continue to learn about the architecture of the Java EE and other knowledge such as APIs. Maybe we are not familiar with these things now, but as we learn, these things will understand.

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What is the EE (i.)