类层次结构
- java.lang.Object 
       
- java.nio.channels.spi.AbstractInterruptibleChannel (implements java.nio.channels.Channel, java.nio.channels.InterruptibleChannel) 
         
- java.nio.channels.SelectableChannel (implements java.nio.channels.Channel) 
           
- java.nio.channels.spi.AbstractSelectableChannel
 
 
 - java.nio.channels.SelectableChannel (implements java.nio.channels.Channel) 
           
 - java.nio.channels.spi.AsynchronousChannelProvider
 - java.nio.channels.SelectionKey 
         
- java.nio.channels.spi.AbstractSelectionKey
 
 - java.nio.channels.Selector (implements java.io.Closeable) 
         
- java.nio.channels.spi.AbstractSelector
 
 - java.nio.channels.spi.SelectorProvider
 
 - java.nio.channels.spi.AbstractInterruptibleChannel (implements java.nio.channels.Channel, java.nio.channels.InterruptibleChannel)