package java.nio.channels; import java.util.*; import java.nio.channels.spi.*; public abstract class Selector { protected Selector() { } static Selector open() { return SelectorProvider.provider().openSelector(); } abstract void close(); abstract boolean isOpen(); abstract Set keys(); abstract SelectorProvider provider(); abstract int select(); abstract int select(long timeout); abstract Set selectedKeys(); abstract Set cancelledKeys(); abstract int selectNow(); abstract Selector wakeup(); }