Jakarta EE

History

• J2EE 1.2
• J2EE 1.3
• J2EE 1.4
• Java EE 5
• Java EE 6
• Java EE 7
• Java EE 8
• Jakarta EE 8
• Jakarta EE 9

  Specifications

Web specifications

• Jakarta Servlet: defines how to manage HTTP requests, in a synchronous or asynchronous way. It is low level and other Jakarta EE specifications rely on it;
• Jakarta WebSocket: API specification that defines a set of APIs to service WebSocket connections;
• Jakarta Server Faces: a technology for constructing user interfaces out of components;
• Jakarta Expression Language is a simple language originally designed to satisfy the specific needs of web application developers. It is used specifically in Jakarta Server Faces to bind components to beans and in Contexts and Dependency Injection to name beans, but can be used throughout the entire platform.

  Web service specifications

• Jakarta RESTful Web Services provides support in creating web services according to the Representational State Transfer architectural pattern;
• Jakarta JSON Processing is a set of specifications to manage information encoded in JSON format;
• Jakarta JSON Binding provides specifications to convert JSON information into or from Java classes;
• Jakarta XML Binding allows mapping XML into Java objects;
• Jakarta XML Web Services can be used to create SOAP web services.

  Enterprise specifications

• Jakarta Contexts and Dependency Injection is a specification to provide a dependency injection container, as in Spring;
• Jakarta Enterprise Beans specification defines a set of lightweight APIs that an object container will support in order to provide transactions, remote procedure calls, concurrency control, dependency injection and access control for business objects. This package contains the Jakarta Enterprise Beans classes and interfaces that define the contracts between the enterprise bean and its clients and between the enterprise bean and the ejb container.
• Jakarta Persistence are specifications about object-relational mapping between relation database tables and Java classes.
• Jakarta Transactions contains the interfaces and annotations to interact with the transaction support offered by Jakarta EE. Even though this API abstracts from the really low-level details, the interfaces are also considered somewhat low-level and the average application developer in Jakarta EE is either assumed to be relying on transparent handling of transactions by the higher level EJB abstractions, or using the annotations provided by this API in combination with CDI managed beans.
• Jakarta Messaging provides a common way for Java programs to create, send, receive and read an enterprise messaging system's messages.

  Other specifications

• Validation: This package contains the annotations and interfaces for the declarative validation support offered by the Bean Validation API. Bean Validation provides a unified way to provide constraints on beans that can be enforced cross-layer. In Jakarta EE, JPA honors bean validation constraints in the persistence layer, while JSF does so in the view layer.
• Jakarta Batch provides the means for batch processing in applications to run long running background tasks that possibly involve a large volume of data and which may need to be periodically executed.
• Jakarta Connectors is a Java-based tool for connecting application servers and enterprise information systems as part of enterprise application integration. This is a low-level API aimed at vendors that the average application developer typically does not come in contact with.

  Web profile

Certified referencing runtimes

Code sample

Example Backing Bean class

Example Data Access Object class

Example Entity class