Oracle Java EE Exams Certification [2020] : practice Java EE

With Java EE Certifications, demonstrate a wide range of skills that extend well beyond fundamental Java programming. Prove that you are capable of architecting systems, defining requirements and overseeing execution when compared to other candidates in the job market.

The Java Platform, Enterprise Edition (Java EE) is a collection of Java APIs owned by Oracle that software developers can use to write server-side applications. It was formerly known as Java 2 Platform, Enterprise Edition, or J2EE.

Sun Microsystems (together with industry partners such as IBM) originally designed Java EE to simplify application development in a thin-client-tiered environment. Java EE simplifies app development and decreases the need for programming by creating standardized, reusable modular components and by enabling the tier to handle many aspects of programming automatically.

Java EE applications are hosted on application servers, such as IBM’s WebSphere, Oracle’s GlassFish or Red Hat’s WildFly server, all of which run either in the cloud or within a corporate data center. While Java EE apps are hosted on the server side, examples of Java EE clients include an internet of things (IoT) device, smartphone, RESTful web service, standard web-based application, WebSocket or even microservices running in a Docker container.

Java EE architecture goals

The Java EE architecture provides services that simplify the most common challenges facing developers when building modern applications, in many cases through APIs, thus making it easier to use popular design patterns and industry-accepted best practices.

For example, one common challenge enterprise developers face is how to handle requests coming in from web-based clients. To simplify this challenge, Java EE provides the Servlet and JavaServer Pages (JSP) APIs, which provide methods for activities like finding out what a user typed into a text field in an online form or storing a cookie on a user’s browser.

Another common task is how to store and retrieve information in a database. To address this goal, Java EE provides the Java Persistence API (JPA,) which makes it easy to map data used within a program to information stored in the tables and rows of a database. Also, creating web services or highly scalable logic components is simplified through the use of the Enterprise JavaBeans (EJB) specification. All of these APIs are well tested, relatively easy for Java developers to learn and can greatly simplify some of the hardest parts of enterprise development.

Java EE core technologies

Along with the four aforementioned APIs, there are more than 30 Java APIs included as Java EE core technologies, with that number to approach 50 with the eventual release of Java EE 8. These Java EE core technologies broadly fall into the following file categories:

• HTTP client technologies. For dealing with HTTP-based clients, Java EE includes the Java API for WebSocket programming, an API for JSON Processing, the JSF and Servlet APIs and the JSP Standard Tag Library (JSTL).
• Database and resource access technologies. For interacting with external and back-end systems, Java EE includes JavaMail, a standard connector architecture, a Java Message Service (JMS) API and a Java Transaction API (JTA) for enforcing two-phase commits.
• REST and web service technologies: To help with the development and deployment of REST-, SOAP-, XML- and JSON-based web services, the Java APIs for RESTful Web Services (JAX-RS) and XML-based web services (JAX-WS) are included, along with APIs for XML messaging and XML registries (JAXR).
• Java EE security and container management: For implementing custom Java EE security and managing Java EE containers, software developers have access to the Java Authorization Contract for Containers and the Java Authentication Service Provider Interface for Containers.

Java EE vs. Java SE

The APIs listed above are just a sampling of the various Java EE components available to developers. All of the APIs defined in the Java Standard Edition, or Java SE, are also offered to Java EE applications.

Java EE does not compete with Java SE, but is instead a superset of APIs that builds upon the foundation provided by Java SE and the standard Java Development Kit (JDK).

Java EE applications build upon the foundation provided by Java SE, and all Java EE applications run on a Java virtual machine that supports all of the APIs defined by Java SE.

Developers today increasingly recognize the need for distributed, transactional, and portable applications that leverage the speed, security, and reliability of server-side technology. Enterprise applications provide the business logic for an enterprise. They are centrally managed and often interact with other enterprise software. In the world of information technology, enterprise applications must be designed, built, and produced for less money, with greater speed, and with fewer resources.

With the Java Platform, Enterprise Edition (Java EE), development of Java enterprise applications has never been easier or faster. The aim of the Java EE platform is to provide developers with a powerful set of APIs while shortening development time, reducing application complexity, and improving application performance.

The Java EE platform is developed through the Java Community Process (JCP), which is responsible for all Java technologies. Expert groups composed of interested parties have created Java Specification Requests (JSRs) to define the various Java EE technologies. The work of the Java Community under the JCP program helps to ensure Java technology’s standards of stability and cross-platform compatibility.

The Java EE platform uses a simplified programming model. XML deployment descriptors are optional. Instead, a developer can simply enter the information as an annotation directly into a Java source file, and the Java EE server will configure the component at deployment and runtime. These annotations are generally used to embed in a program data that would otherwise be furnished in a deployment descriptor. With annotations, you put the specification information in your code next to the program element affected.

In the Java EE platform, dependency injection can be applied to all resources a component needs, effectively hiding the creation and lookup of resources from application code. Dependency injection can be used in Enterprise JavaBeans (EJB) containers, web containers, and application clients. Dependency injection allows the Java EE container to automatically insert references to other required components or resources, using annotations.

This tutorial uses examples to describe the features available in the Java EE platform for developing enterprise applications. Whether you are a new or experienced enterprise developer, you should find the examples and accompanying text a valuable and accessible knowledge base for creating your own solutions.