New APIs in Java 21

Comparing Java 21 (21-ea+6-365-open) with Java 20 (20-ea+32-2328-open).

Element	Modification
java.base
java.io
Console	+ sealed
java.lang.reflect
ClassFileFormatVersion
RELEASE_21	added
java.lang
ThreadGroup
allowThreadSuspension(boolean)	removed
java.compiler
javax.lang.model
SourceVersion
RELEASE_21	added
java.desktop
javax.swing.plaf.synth
SynthComboBoxUI
getMinimumSize(JComponent)	added

Data Source

This report is based on simple comparison of all public and protected APIs of the java.* and javax.* packages of JDK builds 21-ea+6-365-open and 20-ea+32-2328-open. It does not make statements about compatibility.

For the latest Java versions the corresponding CSRs (Compatibility & Specification Review) are linked for a quick reference to find out about the reasoning of the change.

More detailed API comparisons based on the japicmp tool can be found here.