Architecture of Java EE

Java EE is nothing more than a set of specifications implemented by several containers. Containers are Java EE runtime environments which supply certain services to the components they host like concurrency, dependency injection, life-cycle management etc. These components communicate with other components and the Java EE infrastructure using well-defined contracts. Packaging is done using a standard way (using directory structure that is compressed into archive files) before deploying. Java SE APIs can be used by any Java EE componentsas Java EE is a superset of the Java SE platform.

Figure: Standard Java EE containers

Figure shows the logical relationships between various containers. Protocols like RMI-IIOP, HTTP, SSL etc are used by one container to access another.