ThreadGroup methods like stop, destroy, isDestroyed, setDaemon and isDaemon methods are deprecated and will be removed in future release. These API/mechanism to destroy a threadgroup is flawed and such method which supports explicitly or automatically destroying a thread group are terminally deprecated.
Signal Chaining APIs like sigset, signal are obsolete and their use is deprecated. sigaction is cross-platform and is supported API for multi-threaded processes.
java.security.cert APIs representing DNs as Principal or String objects are deprecated.
elliptic curves which are either obsolete or not implemented using modern formulas and techniques of SunEC provider are removed.
The non-public class java.awt.PeerFixer is removed. Its purpose was to provide deserialization support of ScrollPane objects created prior JDK 1.1.1.
jaotc, an experimental Java Ahead-of-Time compilation tool is removed. Experimental Java-based JIT compiler, Graal, is also removed.
root certificates with weak 1024-bit RSA public keys have been removed from the cacerts keystore.