Java EE APIs

As previously mentioned, Java EE is a collection of API specifications designed to work together when developing server-side enterprise Java applications. Java EE 8 APIs include:

• JavaServer Faces (JSF) 2.3
• Java Persistence API (JPA) 2.2
• Enterprise JavaBeans (EJB) 3.2
• Contexts and Dependency Injection for the Java EE Platform (CDI) 2.0
• Java API for JSON Processing (JSON-P) 1.1
• Java API for JSON Binding (JSON-B) 1.0
• Java API for WebSocket 1.0
• Java Message Service (JMS) 2.0
• Java EE Security API 1.0
• Java API for RESTful Web Services (JAX-RS) 2.1
• Java API for XML Web Services (JAX-WS) 2.2
• Servlet 4.0
• Expression Language (EL) 3.0
• JavaServer Pages (JSP) 2.3
• Java Naming and Directory Interface (JNDI) 1.2
• Java Transaction API (JTA) 1.2
• Java Transaction Service (JTS) 1.0
• JavaMail 1.5
• Java EE Connector Architecture (JCA) 1.7
• Java Architecture for XML Binding (JAXB) 2.2
• Java Management Extensions (JMX) 1.2
• Standard Tag Library for JavaServer Pages (JSTL) 1.2
• Bean Validation 2.0
• Managed Beans 1.0
• Interceptors 1.2
• Concurrency Utilities for Java EE 1.0
• Batch Applications for the Java Platform 1.0

The preceding list is a list of specifications, application server vendors or the open source community need to provide implementations for each Java EE API specification. Application server vendors then bundle a set of Java EE API implementations together as part of their application server offerings. Since each implementation is compliant with the corresponding Java EE JSR, code developed against one implementation can run unmodified against any other implementation, avoiding vendor lock-in.

Due to time and space constraints, we won't cover every single Java EE API specification in this book, instead focusing on the most popular Java EE APIs. The following table summarizes the APIs that we will be covering:

We will also cover how to develop microservices by leveraging standard Java EE APIs. Microservices are a modern, popular architectural style in which applications are split up into small modules deployed independently, interacting with each other via the network, typically by leveraging RESTful web services.

We should also note that, with the possible exception of the chapter on microservices, each chapter on this book is standalone; feel free to read the chapters in any order.

Now that we have covered the different APIs provided by Java EE, it is worth reiterating that Java EE is a single standard with multiple implementations, some commercial, and some open source.