Class AbstractSelectableChannel
- java.lang.Object
-
- java.nio.channels.spi.AbstractInterruptibleChannel
-
- java.nio.channels.SelectableChannel
-
- java.nio.channels.spi.AbstractSelectableChannel
- All Implemented Interfaces:
-
Closeable
,AutoCloseable
,Channel
,InterruptibleChannel
- Direct Known Subclasses:
-
DatagramChannel
,Pipe.SinkChannel
,Pipe.SourceChannel
,SctpChannel
,SctpMultiChannel
,SctpServerChannel
,ServerSocketChannel
,SocketChannel
public abstract class AbstractSelectableChannel extends SelectableChannel
Base implementation class for selectable channels.
This class defines methods that handle the mechanics of channel registration, deregistration, and closing. It maintains the current blocking mode of this channel as well as its current set of selection keys. It performs all of the synchronization required to implement the SelectableChannel
specification. Implementations of the abstract protected methods defined in this class need not synchronize against other threads that might be engaged in the same operations.
- Since:
- 1.4
Constructor Summary
Modifier | Constructor | Description |
---|---|---|
protected | AbstractSelectableChannel(SelectorProvider provider) | Initializes a new instance of this class. |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
SelectableChannel | configureBlocking(boolean block) | Adjusts this channel's blocking mode. |
protected void | implCloseChannel() | Closes this channel. |
protected abstract void | implCloseSelectableChannel() | Closes this selectable channel. |
protected abstract void | implConfigureBlocking(boolean block) | Adjusts this channel's blocking mode. |
SelectorProvider | provider() | Returns the provider that created this channel. |
SelectionKey | register(Selector sel,
int ops,
Object att) | Registers this channel with the given selector, returning a selection key. |
Methods declared in class java.nio.channels.SelectableChannel
blockingLock, isBlocking, isRegistered, keyFor, register, validOps
Methods declared in class java.nio.channels.spi.AbstractInterruptibleChannel
begin, close, end
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods declared in interface java.nio.channels.Channel
isOpen
Constructor Detail
AbstractSelectableChannel
protected AbstractSelectableChannel(SelectorProvider provider)
Initializes a new instance of this class.
- Parameters:
-
provider
- The provider that created this channel
Method Detail
provider
public final SelectorProvider provider()
Returns the provider that created this channel.
- Specified by:
-
provider
in classSelectableChannel
- Returns:
- The provider that created this channel
register
public final SelectionKey register(Selector sel, int ops, Object att) throws ClosedChannelException
Registers this channel with the given selector, returning a selection key.
This method first verifies that this channel is open and that the given initial interest set is valid.
If this channel is already registered with the given selector then the selection key representing that registration is returned after setting its interest set to the given value.
Otherwise this channel has not yet been registered with the given selector, so the register
method of the selector is invoked while holding the appropriate locks. The resulting key is added to this channel's key set before being returned.
- Specified by:
-
register
in classSelectableChannel
- Parameters:
-
sel
- The selector with which this channel is to be registered -
ops
- The interest set for the resulting key -
att
- The attachment for the resulting key; may benull
- Returns:
- A key representing the registration of this channel with the given selector
- Throws:
-
ClosedSelectorException
- If the selector is closed -
IllegalBlockingModeException
- If this channel is in blocking mode -
IllegalSelectorException
- If this channel was not created by the same provider as the given selector -
CancelledKeyException
- If this channel is currently registered with the given selector but the corresponding key has already been cancelled -
IllegalArgumentException
- If a bit in theops
set does not correspond to an operation that is supported by this channel, that is, ifset & ~validOps() != 0
-
ClosedChannelException
- If this channel is closed
implCloseChannel
protected final void implCloseChannel() throws IOException
Closes this channel.
This method, which is specified in the AbstractInterruptibleChannel
class and is invoked by the close
method, in turn invokes the implCloseSelectableChannel
method in order to perform the actual work of closing this channel. It then cancels all of this channel's keys.
- Specified by:
-
implCloseChannel
in classAbstractInterruptibleChannel
- Throws:
-
IOException
- If an I/O error occurs while closing the channel
implCloseSelectableChannel
protected abstract void implCloseSelectableChannel() throws IOException
Closes this selectable channel.
This method is invoked by the close
method in order to perform the actual work of closing the channel. This method is only invoked if the channel has not yet been closed, and it is never invoked more than once.
An implementation of this method must arrange for any other thread that is blocked in an I/O operation upon this channel to return immediately, either by throwing an exception or by returning normally.
- Throws:
-
IOException
- If an I/O error occurs
configureBlocking
public final SelectableChannel configureBlocking(boolean block) throws IOException
Adjusts this channel's blocking mode.
If the given blocking mode is different from the current blocking mode then this method invokes the implConfigureBlocking
method, while holding the appropriate locks, in order to change the mode.
- Specified by:
-
configureBlocking
in classSelectableChannel
- Parameters:
-
block
- Iftrue
then this channel will be placed in blocking mode; iffalse
then it will be placed non-blocking mode - Returns:
- This selectable channel
- Throws:
-
ClosedChannelException
- If this channel is closed -
IOException
- If an I/O error occurs
implConfigureBlocking
protected abstract void implConfigureBlocking(boolean block) throws IOException
Adjusts this channel's blocking mode.
This method is invoked by the configureBlocking
method in order to perform the actual work of changing the blocking mode. This method is only invoked if the new mode is different from the current mode.
- Parameters:
-
block
- Iftrue
then this channel will be placed in blocking mode; iffalse
then it will be placed non-blocking mode - Throws:
-
IOException
- If an I/O error occurs