SelectorProvider

public abstract class SelectorProvider extends Object

Service-provider class for selectors and selectable channels.

A selector provider is a concrete subclass of this class that has a zero-argument constructor and implements the abstract methods specified below. A given invocation of the Java virtual machine maintains a single system-wide default provider instance, which is returned by the provider method. The first invocation of that method will locate the default provider as specified below.

The system-wide default provider is used by the static open methods of the DatagramChannel, Pipe, Selector, ServerSocketChannel, and SocketChannel classes. It is also used by the ERROR(System.inheritedChannel()/java.lang.System#inheritedChannel System.inheritedChannel()) method. A program may make use of a provider other than the default provider by instantiating that provider and then directly invoking the open methods defined in this class.

All of the methods in this class are safe for use by multiple concurrent threads.

Protected Constructor Summary

SelectorProvider()
Initializes a new instance of this class.

Public Method Summary

Channel
inheritedChannel()
Returns the channel inherited from the entity that created this Java virtual machine.
abstract DatagramChannel
openDatagramChannel(ProtocolFamily family)
Opens a datagram channel.
abstract DatagramChannel
openDatagramChannel()
Opens a datagram channel.
abstract Pipe
openPipe()
Opens a pipe.
abstract AbstractSelector
openSelector()
Opens a selector.
abstract ServerSocketChannel
openServerSocketChannel()
Opens a server-socket channel.
abstract SocketChannel
openSocketChannel()
Opens a socket channel.
static SelectorProvider
provider()
Returns the system-wide default selector provider for this invocation of the Java virtual machine.

Inherited Method Summary

Protected Constructors

protected SelectorProvider ()

Initializes a new instance of this class.

Throws
SecurityException If a security manager has been installed and it denies RuntimePermission("selectorProvider")

Public Methods

public Channel inheritedChannel ()

Returns the channel inherited from the entity that created this Java virtual machine.

On many operating systems a process, such as a Java virtual machine, can be started in a manner that allows the process to inherit a channel from the entity that created the process. The manner in which this is done is system dependent, as are the possible entities to which the channel may be connected. For example, on UNIX systems, the Internet services daemon (inetd) is used to start programs to service requests when a request arrives on an associated network port. In this example, the process that is started, inherits a channel representing a network socket.

In cases where the inherited channel represents a network socket then the Channel type returned by this method is determined as follows:

  • If the inherited channel represents a stream-oriented connected socket then a SocketChannel is returned. The socket channel is, at least initially, in blocking mode, bound to a socket address, and connected to a peer.

  • If the inherited channel represents a stream-oriented listening socket then a ServerSocketChannel is returned. The server-socket channel is, at least initially, in blocking mode, and bound to a socket address.

  • If the inherited channel is a datagram-oriented socket then a DatagramChannel is returned. The datagram channel is, at least initially, in blocking mode, and bound to a socket address.

In addition to the network-oriented channels described, this method may return other kinds of channels in the future.

The first invocation of this method creates the channel that is returned. Subsequent invocations of this method return the same channel.

Returns
  • The inherited channel, if any, otherwise null.
Throws
IOException If an I/O error occurs
SecurityException If a security manager has been installed and it denies RuntimePermission("inheritedChannel")

public abstract DatagramChannel openDatagramChannel (ProtocolFamily family)

Opens a datagram channel.

Parameters
family The protocol family
Returns
  • A new datagram channel
Throws
UnsupportedOperationException If the specified protocol family is not supported
IOException If an I/O error occurs

public abstract DatagramChannel openDatagramChannel ()

Opens a datagram channel.

Returns
  • The new channel
Throws
IOException

public abstract Pipe openPipe ()

Opens a pipe.

Returns
  • The new pipe
Throws
IOException

public abstract AbstractSelector openSelector ()

Opens a selector.

Returns
  • The new selector
Throws
IOException

public abstract ServerSocketChannel openServerSocketChannel ()

Opens a server-socket channel.

Returns
  • The new channel
Throws
IOException

public abstract SocketChannel openSocketChannel ()