J2EE simplifies application development Author: Not Ran
Sun J2EE (Java2 Enterprise Edition) Architecture provides an intermediate-level integrated framework to meet the needs of applications without too much costs and high availability, high reliability, and scalability. By providing a unified development platform, J2EE reduces the cost and complexity of developing multi-layer applications, while providing strong support for existing applications, fully supporting Enterprise JavaBeans, with good guidance support packaging and deployment applications, add directory support , Enhance the safety mechanism and improve performance. This article describes how J2EE simplifies application development, and it is desirable to make readers to have more in-depth understanding of J2EE.
In today's highly competitive market, various institutions are facing a difficult challenge: to reduce costs in the development cycle, but also provide extensive e-commerce services. In order to solve this problem, many companies are studying how to use Java to implement business logic in the middle layer. Those Java users often find that development is simple, and the deployment is also getting fast. In addition, implementation of distributed Java applications can also increase scalability and reliability.
In the past, Choosing Java companies have encountered safety and performance issues. In many places, these issues have reduced the overall value of Java in the enterprise. Sun has made great efforts to solve these problems, and its recently announced Java 2 Enterprise (J2EE) software development kit (SDK) is the result of this effort.
J2EE is a standard architecture that uses Java language. Today, it takes advantage of it, and companies can easily accelerate distribution deployment in the intermediate layer. Using this architecture in corporate development work, developers will do not have to worry about running key business applications, which can focus on the design and application of business logic.
Sun's J2EE components have several parts, including application programming models, standard implementation platforms to test whether compatibility suits that meet J2EE and implement reference. This latest version of J2EE consolidates features in the Java 2 standard, enhances scalability while smarting Java performance and security issues. Sun also added full support for Enterprise JavaBeans, Java Servlet API, and Java Server Pages (JSP). The ultimate goal is to be an architecture that enables enterprise developers to significantly shorten the market time.
J2EE model
Any person who shoulder highly available and reliable commercial applications know how complicated this work. Establishing access to and managing data from a wide variety of corporate resources often requires a lot of time and money.
The J2EE application programming model (also called J2EEBLUEPRINTS) provides a system model including documentation and instance suite for implementing J2EE-based multi-layer applications, and some simplifying this complex work. It should be used as the principles of developers to design and optimize components to divide development work from strategies to distribute technical resources. In accordance with this model, it will ensure that a J2EE application is identical to the other features.
J2EE Application Programming Model requires developers to divide their work into two categories: business logic and representation logic. The rest is automatically handled by system resources. It is not necessary to encode the intermediate pipeline. Developers can spend more time in business and representation logically, and this transformation is popular for companies that pay attention to shortening project cycles.
J2EE platform
The J2EE platform is a standard environment that runs J2EE applications. It is deployed by J2EE (standards that all J2EE platform products must be supported), IETF standard sets and CORBA standards. The latest J2EE platform also adds a JavaBean component model. Developers can use the JavaBean component model from defining Java class instances and access Java classes through the defined events.
As mentioned earlier, J2EE supports EJB, so developers can perform multi-user and transaction functions. Enterprise JavaBeans divide the application logic into reuse and scalable code segments when running on the J2EE server. Enterprise Javabeans is not a new feature of this product, but J2EE enhances their capacity and portability by defining standard client and service API. EJB runs within one container of the server, which provides all typical intermediate services such as transaction management, security, remote customer connection, survival cycle management, and database connection buffer.
In order to allow the transaction system to run in the presence of an EJB container, developers only need to define the transaction attribute of Beans in the deployment description file. In this way, you don't have to develop code to manage the borders that are easy to errors.
J2EE server
Sun's J2EE server provides naming and directory services through Java Naming and Directory Interface (JNDI), certified, HTTP, and EnterpriseJavabeans compatible with the EnterpriseJavabeans. JNDI is a standard extension of the Java platform that provides applications with unified interfaces with Java features to the company's naming and directory services, including LDAP.
J2EE servers also use JavaServlet technology. Servlet (It can be seen as a small program running on the server) provides developers-based, creating a web-based application independently of a platform-based method, which is unlikely to have performance limitations as using CGI programs. Servlet is a simple and similar technique that expands the web server function, and because it is written in Java, it is possible to access the entire Java API library, including JDBC APIs for accessing the enterprise database.
JSP is an extension of Java Servlet. Servlet provides development and displaying an interactive web page from the server, while JSP has further improved, which makes created and supported HTML and XML pages combined with static templates and dynamic content easier.
Calm heart
We have discussed the technology of constituent platforms in detail, but no new features of SDK have not been involved. A fundamental feature is a compatibility test kit. This tool is mainly used to confirm whether a Java application complies with the J2EE platform specification, which is encapsulated by three test components. The first is a test for basic API-level compatibility, using a classified signature test to ensure that all implementation APIs are neither a collection of API sets, nor a subset.
The second test is actually a supercoming of tests to ensure that all components are operating properly. The third test check end is the peer compatibility. The compatibility test kit makes the user, their J2EE application will cooperate with each other.
J2EE also includes a set of implementation of the reference, in addition to the J2EE platform operations used by the manufacturer and the company, or the guiding principle of developers confirmed the compatibility of some applications.
J2EE has a value
If you want to make sure your application is built in a compatible manner, which is scalable, reliable and compatible with other enterprise applications, it is recommended that you use J2EE. Its deployment and deployment techniques, fast implementation speeds and security, making it a good technology that can carry your business application framework. It can alleviate the burden of certain intermediate pipeline projects, and developers will be interested in re-coding.
