Some of the important technologies provided by J2EE are:

• Java API for XML-Based RPC (JAX-RPC): This is used to build web services and clients that make use of XML and Remote Procedure Calls.
• Java Server Pages (JSP): This is used for delivering XML and HTML documents. Apart from these, we can make use of OutputStream for delivering other data types as well.
• Java Servlets: Servlets are classes used for extending the server capabilities which hosts applications and can be accessed using the request-response model.

• Enterprise Java Beans (EJB): This is a server-side component that is used for encapsulating the application’s business logic by providing runtime environment, security, servlet LIFECYCLE management, transaction management and other services.
• J2EE Connector ARCHITECTURE: This defines standard architecture to CONNECT J2EE platforms to different EIS (Enterprise Information Systems) such as mainframe processes, database systems and different legacy applications coded in another language.
• J2EE Deployment API: Provides specifications for web services deployment
• Java Management Extensions (JMX): They are used for supplying tools for monitoring and managing applications, objects, devices and networks.
• J2EE Authorization Contract for Containers (JACC): This is used to define security contracts between authorization policy modules and application servers.
• Java API for XML Registries (JAXR): This provides standard API to access different XML Registries to enable infrastructure for the building and deployment of web services.
• Java Message Service (JMS): This is a messaging standard for allowing different JEE components for creating, SENDING, receiving and reading messages by enabling communication in a distributed, loosely coupled, asynchronous and reliable manner.
• Java Naming and Directory Interface (JNDI): This is an API that provides naming and directory functionality for Java-based applications.
• Java Transaction API (JTA): This is used for specifying Java standard interfaces between transaction systems and managers.
• Common Object Request Broker Architecture (CORBA): This provides a standard for defining Object Management Group designed for facilitating system communication deployed on diverse platforms.
• JDBC data access API: This provides API for getting data from any data sources like flat files, spreadsheets, relational databases etc.