Day One of JavaOne 2025, in conjunction with the release of JDK 24, was held on March 18th, 2025, at the Oracle Conference Center in Redwood Shores, California. Key takeaways included: Scott McNealy providing a retrospective on how Java was created; Mark Reinhold discussing how Oracle stewards Java by balancing conservation with innovation; and an enumeration of 11 developer pain points and their respective solutions.
What follows is a summary of the keynote address and highlighted presentations.
Opening Keynote: Our World, Moved by Java
Chad Arimura, vice president, Java Developer Relations at Oracle, facilitated this keynote address entitled, Our World, Moved by Java. Arimura opened with the original quote from Sun Microsystems that characterized Java:
Java is simple, object-oriented, distributed, interpreted, robust, secure, architecture neutral, portable, high performance, multithreaded dynamic language.
After a short walk down memory lane dating back to the first JavaOne, Arimura maintained how Java is better and faster with every release. He then introduced: Georges Saab, senior vice president, Java Development at Oracle; Scott McNealy, founder of Sun Microsystems, co-founder and board member at Curriki and Chairman Emeritus at LittleHorse; and Colt McNealy, Scott's son, managing member of the LLC and leader of technical staff at LittleHorse.
After stating that Java almost didn't happen, Scott McNealy recalled how he convinced James Gosling to stay at Sun Microsystems after Gosling wanted to pursue other interests. McNealy enticed Gosling to remain at Sun by offering all the resources he needed to follow his passion. And, of course, the rest is history.
McNealy provided an additional, sometimes humorous, retrospective on the state of software companies 30 years ago and how Sun interacted with them for licensing Java. He recalled how he got in trouble back then for characterizing Compaq and Hewlett Packard as a "collision of two garbage trucks."
In the early days of Java, McNealy was featured on the cover of the October 13, 1997 issue of Fortune.
To discuss the technical aspects of Java, Saab introduced Mark Reinhold, senior architect, Java Platform Group at Oracle. Reinhold stated that Java remains the one of the most popular programming platforms in the world and its success is based on a relentless focus on two main goals: developer productivity and program performance. The Oracle team pursues these goals in face of changing programming paradigms, and evolving applications, deployment styles and hardware.
As important as the goals we choose, are the means by which we work to achieve them.
We take the time to think about the big picture and the long term. We don't act only as developers, we also try to act as stewards.
We try to be responsible for overseeing and protecting something considered worth caring for and preserving. We try to preserve the past while evolving for the future.
Stewardship of the Java platform is guided by two key values: readability and compatibility.
Reinhold's predecessor, Graham Hamilton, espoused three main points on readability as: "reading is more important than writing; simplicity matters; and Java should be one language with the same meaning everywhere." Reinhold, quoting his favorite characterization of readability from Harold Abelson and Gerald Jay Sussman, both professors at MIT, stated:
Programs are meant to be read by humans and only incidentally for computers to execute.
When describing the different types of compatibility, namely: source; binary; behavioral; migration; and intellectual, Reinhold focused on intellectual compatibility "which means that new features are built on existing knowledge, rather than destroy it."
To preserve the significant amount of time that developers have invested in the Java platform, Reinhold stated that there should be a balance between conservation and innovation. He stated that we "must have the guts to say no" because, as Gosling once said, "we must have the courage to do no thing rather than the wrong thing."
In Oracle's quest to improve developer productivity and program performance, as described earlier, Reinhold stated that they look for pain points. He introduced, and provided solutions for, all of these 11 pain points:
- "Java is too difficult to teach!"
- "Virtual threads don't scale when I use synchronized!"
- "GC pauses are too long!"
- "ZGC scales poorly on some workloads!"
- "Java programs sometimes start up too slowly!"
- "Using native libraries is too hard!"
- "Quantum computing will break RSA!"
- "The stream API isn't fully extensible!"
- "My favorite bytecode library breaks on JDK 24!"
- "Writing raw HTML in Javadoc comments is tedious!"
- "You're not delivering new features quickly enough!"
Arimura concluded the opening keynote by introducing the new Learn.java website, "a place for beginners, students, and teachers of the Java programming language." This new website complements the work with the Java in Education initiative, a collaboration between Oracle and Java User Groups.
Highlighted Presentations: Next Generation Apps with Java 21 | SQL, JSON and Java
Building Next-Gen Apps with Java 21 and Oracle Database, presented by Anders Swanson, developer evangelist at Oracle. Swanson kicked off his presentation by defining a Converged Database as "any data, any workload, one database." A more formal definition states that converged databases "offer a unified platform for storing, managing, and analyzing a wide range of data types and workloads, including relational, JSON, spatial, graph, vector and more."
Swanson defined the problem with microservices and distributed systems are challenging to correctly implement them at scale. Converged databases offer an opportunity to provide a more robust, scalable data platform that eliminates operational overhead.
Swanson maintained that developers should use converged databases to "eliminate the need for multiple specialized systems by storing, indexing and querying data on a single platform."
Developers interested in experimenting with Swanson's example demos may do so by cloning this GitHub repository.
SQL, JSON, and Java, presented by Josh Spiegel, software architect at Oracle. Spiegel kicked off his presentation by introducing the OSON, Oracle's optimized native binary storage format for JSON used in the Oracle Autonomous JSON Database. He defined three models:
Streaming | Tree/DOM | Data Binding
These models are easier to use from left to right, and offer more performance and control from right to left.
Working with data using the Streaming model was accomplished using the OracleJsonGenerator interface and writing objects with the Java FileOutputStream class.
Data Binding to a Plain Old Java Object was accomplished with Jackson and OSON and included two mapping goals: no intermediate representations, e.g. JSON text and an instance of a Java HashTable; and to preserve types, e.g., timestamps and numeric representations. Spiegel demonstrated how to retrieve and send data in JSON and OSON formats via the usual JDBC methods.
An Oracle database is compatible with Spring Data technologies such as Spring Data JDBC, Spring Data JPA and Spring Data MongoDB.
Developers interested in experimenting with Spiegle's example demos may do so by cloning this GitHub repository.
Conclusion
JavaOne 2025, a three-day event consisting of keynotes, presentations and hands-on labs, is organized by Oracle and the developer relations team. The session catalog provides all of the details and developers can watch the JDK 24 Launch Party that includes the opening keynote.
About the Author
