The Java runtime offers a host of guarantees like memory safety, type safety, encapsulation, and many more. What makes these aspirations actual guarantees is a property called “integrity”. But there are a few mechanisms in Java that allow undermining integrity - some for good, some for less good reasons. Integrity by default states that all such operations need to be disabled by default. Today we discuss why that is so important, what the progress toward this goal has been, and what Java developers need to know to keep their applications going.

Nicolai Parlog talks to Ron Pressler, who is Java Architect at Oracle and, among other things, lead of Project Loom.

The Stable Values API is a preview feature in Java 25 that allows developers to define immutable objects that are initialized at most once. It combines the flexibility of lazy initialization with the performance advantages of final fields.

In this episode, Ana hosts Per Minborg, a member of the Java Core Library team at Oracle and co-author of JEP 502 on Stable Values. Per explains the concept behind Stable Values and how this approach addresses the drawbacks of eager initialization in Java. By deferring the creation of expensive resources until they are actually needed, Stable Values contribute to more efficient application startup. He also discusses the design process and specifics of the API, highlighting its benefits in multi-threaded environments—particularly its ability to ensure thread-safe, at-most-once initialization without the need for complex synchronization mechanisms.

OpenJDK's Project Leyden aims to improve the startup and warmup time of Java applications, for now by shifting computation from those phases to the applications' build time. Java 24 ships with ahead-of-time class loading and linking, which is the first step in that direction. In this episode, we learn about that as well as about Leyden's approach to reach its goals and some features that are available in its early access build plus some that aren't.

Nicolai Parlog discusses with Dan Heidinga, who is JVM Runtime Architect at Oracle and, among other things, member of projects Leyden and Valhalla.