Java EE 5 is an abbreviation of "Java Platform, Enterprise Edition 5". It is a standard proposed for enterprise systems by Sun Microsystems, Inc. (now Oracle Corporation) related to Java platforms. To the Java SE set of standard functions, Java EE adds a set of functions intended for Servlets, EJB, and other server applications used for the development of business systems. Application servers implement handling as components, various services, communication methods, and so on, in accordance with these conventions as a Java EE 5 platform, thereby providing technology for creating multi-tiered applications that combine reusable components.
Under Java EE 5, applications are provided as EAR (Enterprise ARchive) files. Web applications, EJB, and other Java EE 5 modules are archived and included in the EAR file. A mutual reference relationship can be set between the modules within an EAR file. By deploying a Java EE 5 application included in an EAR file to a Java EE 5 platform, it can operate without the need to set classpaths and so on.
The application development method centering on EJB and Web service applications has changed considerably. In addition, innovations such as the ability to use Dependency Injection using annotation have greatly changed resource and object referencing methods. Deployment as an EAR file means that deployment descriptors (application.xml) are no longer required.
These changes have made it simple to develop applications.
