computer science

Jakarta EE

Jakarta EE is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Jakarta EE rather than just read about it. In short: Jakarta EE, formerly Java Platform, Enterprise Edition (Java EE) and Java 2 Platform, Enterprise Edition (J2EE), is a set of specifications, extending Java SE with specifications for enterprise features such as distributed computing and web services. Jakarta EE applications are run on reference runtimes, which can be microservices or application servers, which handle transactions, security, scalability, concurrency…

Key takeaways

Jakarta EE belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Jakarta EE to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Jakarta EE from memory before moving on to harder problems.

Reference excerpt

Jakarta EE, formerly Java Platform, Enterprise Edition (Java EE) and Java 2 Platform, Enterprise Edition (J2EE), is a set of specifications, extending Java SE with specifications for enterprise features such as distributed computing and web services. Jakarta EE applications are run on reference runtimes, which can be microservices or application servers, which handle transactions, security, scalability, concurrency and management of the components they are deploying. Jakarta EE is defined by its specification. The specification defines APIs (application programming interface) and their interactions. As with other Java Community Process specifications, providers must meet certain conformance requirements in order to declare their products as Jakarta EE compliant. Examples of contexts in which Jakarta EE referencing runtimes are used are: e-commerce, accounting, banking information systems.

History The platform created by Sun Microsystems was known as Java 2 Platform, Enterprise Edition or J2EE from version 1.2, until the name was changed to Java Platform, Enterprise Edition or Java EE in version 1.5. After Sun was acquired in 2009, Java EE was maintained by Oracle under the Java Community Process. On September 12, 2017, Oracle Corporation announced that it would submit Java EE to the Eclipse Foundation. The Eclipse top-level project has been named Eclipse Enterprise for Java (EE4J). The Eclipse Foundation could not agree with Oracle over the use of javax and Java trademarks. Oracle owns the trademark for the name "Java" and the platform was renamed from Java EE to Jakarta EE. The name refers to the largest city on the island of Java and also the capital of Indonesia, Jakarta. The name should not be confused with the former Jakarta Project which fostered a number of current and former Java projects at the Apache Software Foundation.

Specifications Jakarta EE includes several specifications that serve different purposes, like generating web pages, reading and writing from a database in a transactional way, and managing distributed queues. The Jakarta EE APIs include several technologies that extend the functionality of the base Java SE APIs, such as Jakarta Enterprise Beans, connectors, servlets, Jakarta Server Pages and several web service technologies.

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 Faces: a technology for constructing user interfaces out of components; Jakarta Expression Language (EL) is a simple language originally designed to satisfy the specific needs of web application developers. It is used specifically in Jakarta Faces to bind components to (backing) beans and in Contexts and Dependency Injection to named 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 (REST) 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 Activation (JAF) specifies an architecture to extend component Beans by providing data typing and bindings of such types. Jakarta Contexts and Dependency Injection (CDI) is a specification to provide a dependency injection container; Jakarta Enterprise Beans (EJB) specification defines a set of lightweight APIs that an object container (the EJB container) will support in order to provide transactions (using JTA), remote procedure calls (using RMI or RMI-IIOP), 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 (JPA) are specifications about object-relational mapping between relation database tables and Java classes. Jakarta Transactions (JTA) 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 in implementing the X/Open XA standard, 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 (JMS) provides a common way for Java programs to create, send, receive and read an enterprise messaging system's messages.

Other specifications Jakarta Validation: This package contains the annotations and interfaces for the declarative validation support offered by the Jakarta Validation API. Jakarta Validation provides a unified way to provide constraints on beans (e.g. Jakarta Persistence model classes) that can be enforced cross-layer. In Jakarta EE, Jakarta Persistence 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 (EIS) as part of enterprise application integration (EAI). This is a low-level API aimed at vendors that the average application developer typically does not come in contact with.

Web profile In an attempt to limit the footprint of web containers, both in physical and in conceptual terms, the web profile was created, a subset of the Jakarta EE specifications. The Jakarta EE web profile comprises the following:

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Jakarta EE

Start with the simplest possible case. Write down what Jakarta EE claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Jakarta EE before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Jakarta EE ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Jakarta EE

In research: Jakarta EE appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Jakarta EE in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Jakarta EE is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computing platforms, Java (software platform), Java enterprise platform, so understanding it makes those chapters shorter.
In everyday life: Look for Jakarta EE outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Jakarta EE in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Jakarta EE means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Jakarta EE out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Jakarta EE in simple terms?

Why does Jakarta EE matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Jakarta EE?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Jakarta EE.