Rudy De Busscher

By now, we all know that JDK 17 is the latest Java long-term supported release with several new language features. There are already many resources that explain the Java Record and Text Blocks in detail. But JDK 17 has much more interesting changes since JDK 11.

In this session, I go into more detail about some other interesting changes that are not language features but are a good reason to switch to JDK 17.

• Improvements in the Class Data Sharing feature.
• JDK Flight Recorder for monitoring purposes.
• Improvements in Performances in the Garbage collectors
• Preventing security issues with context-specific deserialization filters.

Besides the explanation, you also see these changes in action with some demos.

Java Byte code is OS independent, which means that your application's startup takes more time than a native image. Using the Class Data Sharing functionality introduced in more recent versions of the JVM, you can prepare your application so that it will load very fast.

In this presentation, I'll go into more detail what Class Data Sharing is and how you can use it on an OpenJDK versions. With some Jakarta EE demo applications, you will see gains that you can achieve and reduce memory footprint a lot in Docker containers by sharing memory.