RELEASE NOTES: JDK 21.0.8

`TypeMirror` Changed to Provide Annotations for Types Loaded from Bytecode

The implementation of TypeMirror now provides access to annotations for types loaded from bytecode. Previously type annotations were not associated with types loaded from bytecode.

Annotation processors can access type annotations for elements using AnnotationMirror#getAnnotationMirrors, and the annotations will be included in the output of AnnotationMirror#toString.

Any programs that relied on annotations being omitted for elements loaded from the classpath should be updated to handle type annotations.

java.net.http.HttpClient Is Enhanced to Report HTTP/2 Flow Control Errors to the Server

The java.net.http.HttpClient will now report HTTP/2 flow control errors to the server when they are detected. This is an implementation detail that should be transparent to users of the HttpClient API, but could result in streams being reset or connections being closed if connecting to a non-conformant HTTP/2 server.

Incorrect result of Integer.numberOfLeadingZeros

Integer.numberOfLeadingZeros may return an incorrect result on x86_64 with AVX2. The issue is caused by an incorrect JIT compiler optimization. As a workaround, the following command-line options can be used -XX:+UnlockDiagnosticVMOptions -XX:DisableIntrinsic=_numberOfLeadingZeros_i.

New System.map and System.dump_map Diagnostic Commands Have Been Added

New System.map and System.dump_map diagnostic commands have been added to jcmd. When executed, these commands print the virtual memory map of the JVM process, together with Native Memory Tracking information about the virtual memory segments. For the latter information to be displayed, Native Memory Tracking must be enabled.

jcmd <pid> System.map will print the virtual memory map of the JVM indicated by <pid> to the stdout of jcmd.

jcmd <pid> System.dump_map will cause the target JVM indicated by <pid> to print the virtual memory map to a file named vm_memory_map_<pid>.txt into the current directory of the target JVM.

Removed Baltimore CyberTrust Root Certificate after expiry date

The following expired root certificate has been removed from the cacerts keystore: ` + alias name "baltimorecybertrustca [jdk]" Distinguished Name: CN=Baltimore CyberTrust Root, OU=CyberTrust, O=Baltimore, C=IE `