David R. Heffelfinger - Payara Micro Revealed: Cloud-Native Application Development with Java

David R. Heffelfinger

Payara Micro Revealed

Cloud-Native Application Development with Java

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Any source code or other supplementary material referenced by the author in this book is available to readers on GitHub.

About the Author

David Heffelfinger

is an independent consultant at Ensode Technology, LLC ( www.ensode.com ). David has authored several books on Jakarta EE and related technologies. He is a frequent speaker at tech conferences such as JavaOne and Oracle Code One. David has served in the JavaOne content committee on multiple occasions. He was named one of 39 Java leaders and experts to follow on Twitter, where you can find him under the handle @ensode.

About the Technical Reviewer

Andres Sacco

has been working as a developer since 2007 in different languages including Java, PHP, NodeJs, and Android. Most of his background is in Java and the libraries or frameworks associated with this language, for example, Spring, Hibernate, JSF, and Quarkus. In most of the companies that he worked for, he researched new technologies in order to improve the performance, stability, and quality of the applications of each company.

Payara is a Jakarta EE and MicroProfilecompliant runtime; both of these are specifications dictating standards for server-side and cloud-based applications. In this chapter, we will provide a brief history of server-side Java and Payara to give some context on how we got to where we are today.

The Java language was released to the world by Sun Microsystems in 1995, and it took the world by storm. In the beginning , the killer feature of Java was Java applets, a technology that allowed rich desktop-like applications to run inside web browsers.

Sun Microsystems started expanding the Java language beyond desktop applications, splitting the language into three editions in 1999; the three editions were called J2SE (Java 2 Standard Edition), J2ME (Java 2, Micro Edition), and J2EE (Java 2, Enterprise Edition).

The introduction of J2EE back in 1999 was a huge success. Sun Microsystems created a standard that other vendors could implement, demand for J2EE soared, and a large number of vendors created products implementing the standard. Some of those products still exist today, like Red Hat JBoss, Oracle WebLogic, and IBM WebSphere application servers.

J2EE was a huge success; it provided APIs that were previously part of the Java language, such as servlets, used to generate markup (typically HTML) on the server, to be displayed on the client (typically a web browser). J2EE introduced several new APIs and technologies that became very popular, such as Java Server Pages (JSP), which made it easier to generate markup server side than it was possible with servlets, and Enterprise Java Beans (EJB), which automated a lot of enterprise requirements such as transactions and security.

J2EE was such a huge success that, even though competing server-side Java technologies emerged, such as the popular Spring Framework, the term J2EE became a generic term meaning server-side Java. It wasnt uncommon for job postings to request J2EE expertise, where the position in question required minimal, if any, actual J2EE knowledge, instead focusing on competing Java technologies.

To this day, it isnt that uncommon to find the term J2EE in job postings and even in informal conversations related to server-side Java, even though J2EE has been obsolete for several years, superseded by Java EE way back in 2006.

Although widely popular, J2EE gained a reputation for being complex and difficult to use. As such, several competing technologies started popping up, claiming to provide equivalent functionality to J2EE, while being easier to work with. Some prominent J2EE competitors at the time included Ruby on Rails and the Spring Framework.

As a response to these competing technologies, Sun Microsystems introduced Java EE (Java, Enterprise Edition) in 2006. Java EE introduced the heavy use of annotations for application configuration, greatly simplifying the task of configuring and developing server-side Java applications.

Some time after the release of Java EE, Oracle Corporation acquired Sun Microsystems; as such, Oracle became the new steward of the Java language and, by extension, of Java EE.

Java EE applications, like J2EE before it, were originally meant to be deployed to an application server, which is a piece of enterprise software that takes care of a lot of the plumbing of the application, freeing application developers to focus on implementing business logic. These application servers tend to be resource heavy, needing large amounts of computing resources such as RAM and CPU.