Java IO (File; Streams, Reader, Writer, Serialization)URL & HTTP NIO (Files. Paths, Channel, Gathering, Scanning, Walk)XML & JAX-P (XML, XSchema; XSL Transform; JAX-P : SAX Parser, DOM Builder)Multi-Threaded (Thread, Runnable, Virtual Trend, Thread Local, Synchronization, Timer)Concurrency (Executor; Future, Callable, Synchronization, Lock, Atomic, Scoped Value, Fork / Join; Structured Concurrency, Flow API (Reactive))Class Loading & ReflectionNetwork / Socket Programming (Server & Client Sockets, TCP/UDP)Protocols (RMI, Email (POP3, SMTP, IMAP), FTP)
