Chapter 3. OpenJDK features The latest Red Hat build of OpenJDK 17 release might include new features. Additionally, the latest release might enhance, deprecate, or remove features that originated from Red Hat build of OpenJDK 17 releases. Note For all the other changes and security fixes, see OpenJDK 17.0.2 Released . 3.1. New features and enhancements Review the following release notes to understand new features and feature enhancements that have been included with the Red Hat build of OpenJDK 17.0.2 release: IANA Time Zone Database The Internet Assigned Numbers Authority (IANA) updated its Time Zone Database to version 2021c. Red Hat OpenJDK date and time libraries depends on IANA's Time Zone Database for determining local time for various regions around the world. Note The 2021b release of the Time Zone Database updated time zone rules that existed before 1970. For more information about the 2021b release, see 2021b release of tz code and data available on the IANA website. For more information about IANA's 2021c Time Zone Database release, see JDK-8274857 . For more information about IANA's Time Zone Database, see Time Zone Database on the IANA website. 3.2. OpenJDK enhancements Red Hat build of OpenJDK 17 provides enhancements to features originally created in releases of Red Hat build of OpenJDK. OpenJDK's identification of Microsoft Windows versions Before the Red Hat build of OpenJDK 17 release, the os.name system property that is retrieved from System.getProperty() and the HotSpot error logs would report Windows 10.0 on Microsoft Windows 11 and Windows Server 2019 on Microsoft Windows Server 2022. Red Hat build of OpenJDK now identifies the correct version on these systems. System property behavior change Red Hat build of OpenJDK 17 reverts the behavior of the file.encoding system property to a state identical to Red Hat build of OpenJDK 11 on most supported platforms, except for macOS. This change improves how the system property behaves on the Microsoft Windows platform, where the system locales and user locales differ. For more information about the behavior change to the file.encoding system property, see JDK-8275343 . Vector class update Red Hat build of OpenJDK 17 updates the java.util.Vector class, so that this class now reports any ClassNotFoundException messages that have been generated with the java.io.ObjectInputStream.GetField.get(name, object) method during the deserialization process. These exception messages occur when a vector's class, wrapped inside an element, is not found. Before the java.util.Vector class update, the class reported any StreamCorruptedException messages when the previously detailed incident occurred. A StreamCorruptedException message does not provide information about a missing class. For more information about the update to the java.util.Vector class, see JDK-8277157 . Z Garbage Collector bug fix Before the Red Hat build of OpenJDK 17 update, the Z Garbage Collector (ZGC) experienced lengthy Concurrent Process Non-strong References times that caused latency and throughput issues for Java applications that use ZGC for memory management. You could determine these lengthy times by entering the -Xlog:gc* against a garbage collector (GC) log in your command-line interface. The Red Hat build of OpenJDK 17 release removes the bug that caused these issues, so the ZGC can now achieve shorter Concurrent Process Non-strong References times. For more information about ZGC bug fix, see JDK-8277533 . 3.3. Deprecated and removed features Review the following release notes to understand pre-existing features that have been either deprecated or removed in the Red Hat build of OpenJDK 17.0.2 release: Google GlobalSign root certificate Red Hat build of OpenJDK 17.0.2 removes the following root certificate from the cacerts keystore: Alias name globalsignr2ca [jdk] Distinguished name CN=GlobalSign, O=GlobalSign, OU=GlobalSign Root CA - R2 For more information about this removed Google GlobalSign root certificate, see JDK-8272535 .

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