public abstract class SelectorProvider extends Object
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 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.
| Modifier | Constructor and Description |
|---|---|
protected |
SelectorProvider()
Initializes a new instance of this class.
|
| Modifier and Type | Method and Description |
|---|---|
Channel |
inheritedChannel()
Returns the channel inherited from the entity that created this
Java virtual machine.
|
abstract DatagramChannel |
openDatagramChannel()
Opens a datagram channel.
|
abstract DatagramChannel |
openDatagramChannel(ProtocolFamily family)
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.
|
protected SelectorProvider()
SecurityException - If a security manager has been installed and it denies
RuntimePermission("selectorProvider")public static SelectorProvider provider()
The first invocation of this method locates the default provider object as follows:
If the system property java.nio.channels.spi.SelectorProvider is defined then it is taken to be the fully-qualified name of a concrete provider class. The class is loaded and instantiated; if this process fails then an unspecified error is thrown.
If a provider class has been installed in a jar file that is visible to the system class loader, and that jar file contains a provider-configuration file named java.nio.channels.spi.SelectorProvider in the resource directory META-INF/services, then the first class name specified in that file is taken. The class is loaded and instantiated; if this process fails then an unspecified error is thrown.
Finally, if no provider has been specified by any of the above means then the system-default provider class is instantiated and the result is returned.
Subsequent invocations of this method return the provider that was returned by the first invocation.
public abstract DatagramChannel openDatagramChannel() throws IOException
IOException - If an I/O error occurspublic abstract DatagramChannel openDatagramChannel(ProtocolFamily family) throws IOException
family - The protocol familyUnsupportedOperationException - If the specified protocol family is not supportedIOException - If an I/O error occurspublic abstract Pipe openPipe() throws IOException
IOException - If an I/O error occurspublic abstract AbstractSelector openSelector() throws IOException
IOException - If an I/O error occurspublic abstract ServerSocketChannel openServerSocketChannel() throws IOException
IOException - If an I/O error occurspublic abstract SocketChannel openSocketChannel() throws IOException
IOException - If an I/O error occurspublic Channel inheritedChannel() throws IOException
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.
IOException - If an I/O error occursSecurityException - If a security manager has been installed and it denies
RuntimePermission("inheritedChannel") Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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