Understanding the basics of Java EE
Java is a legacy language and platform that has survived through the decades because it tasks itself with evolving as the new age development requirements. The Java Enterprise Edition (Java EE) is one such evolution step that has made it a favorite amongst companies that offer Java application development.
Its ‘write once, run anywhere’ paradigm (due to JVM – Java Virtual Machine) has effectively been utilized to write code that works across devices – laptops, smartphones, tablets, etc.
The major building blocks of J2EE or Java for Enterprise Edition platform are:
- Compiler – converts source code into Java code.
- Loader – interprets Java class file into readable format.
- JAR – an assembly of Java class related libraries.
- Java Doc – an automatic documentation generator.
- JDB – the database documentation generator.
The typical Java EE application architecture
The multi-tier architecture provided by J2EE is one of a kind and enables Java application development to be accessible, scalable, and manageable as per the requirements of the enterprise-level application being developed.
Following are the tiers provided by J2EE:
- Client Tier – These applications run in an environment other than the Java EE server. They can be web browsers, standalone desktop applications, or even other servers. The server processes the client tier requests, and sends back the response with minimal overhead.
- Middle Tier – The main business logic of the application resides in the business tier. Before sending the response, the client requests are processed in this tier through various authentication, analysis, and data transformation methods.
- Data Tier – It is a collective name for the legacy systems, enterprise resource planning systems, and databases that hold the workforce information, customer information as well as important documents and data related to internal and consumer-facing enterprise applications.
There are also several frameworks and ‘tier-developers’ available for J2EE development.
These tools reduce redundant hand coding by enabling Java developers to design, generate, and deploy middle-tier data objects rapidly through an ergonomic interface. They allow the developer to map data objects to tables with custom attribute selection. These tier developers can work with custom hooks, web services, multiple database connections and parent-child relationships.
They can be used by just paying developer license fees, and J2EE applications can be developed using the following steps:
- Keep the database ready for integration.
- Identify the database interactions of the application.
- Create a Tier Developer project. (For example, Alachisoft.)
- This generates and runs 50% of the application immediately.
- Develop the remaining 50% by inserting the appropriate business logic.
Important Enterprise Frameworks
- Struts 2 – Developed by Apache, this is an enterprise ready framework that streamlines the entire product development life-cycle. Struts 2 has been developed by collaboration of Webwork and Struts community. It creates dynamic responses and is particularly used in HTTP-independent framework interfaces.
- Seam – Developed by JBoss, this is essentially a Java Web Application framework, but comes in handy in the enterprise scenario too as it provides full stack development options including Ajax, JavaServer Faces (JSF), Java Persistence (JPA), Enterprise Java Beans (EJB 3.0) and Business Process Management (BPM). It provides WYSIWYG quality applications that are facilitated by JBoss. This eliminates complexity at both – the application level and the API level.
- OpenXava – This framework helps developing Ajax applications with Java enterprise (J2EE). This is mainly aimed at improving the productivity. It manages to do exactly that by providing a full-fledged application in response to developers providing only the JPA classes. This is mainly used to develop complex real life applications that are heavy on the business logic side, as it requires no code generation. Its major feature is its speed – that makes it faster than the popular frameworks like Spring MVC, Ruby on Rails, etc.