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§4.3 Class DatagramSocket
public class java.net.DatagramSocket
extends java.lang.Object (I-§1.12)
{
// Constructors
public DatagramSocket(); §4.3.1
public DatagramSocket(int port); §4.3.2
// Methods
public void close(); §4.3.3
protected void finalize(); §4.3.4
public int getLocalPort(); §4.3.5
public void receive(DatagramPacket p); §4.3.6
public void send(DatagramPacket p); §4.3.7
}
This class represents a socket for sending and receiving datagram packets (§4.2).
A datagram socket is the sending or receiving point for a connectionless packet delivery
service. Each packet sent or received on a datagram socket is individually addressed and
routed. Multiple packets sent from a machine to another may be routed differently, and
may arrive in any order.
DatagramSocket
public DatagramSocket()
throws SocketException
- Constructs a datagram socket and binds it to any available port on the local
host machine.
- Throws
- SocketException (I-§4.17)
- if the socket could not be opened, or the socket could not bind the
specified local port.
DatagramSocket
public DatagramSocket(int port)
throws SocketException
- Constructs a datagram socket and binds it to the specified port on the local
host machine.
- Parameters:
local
-
port to use
- Throws
- SocketException (I-§4.17)
- if the socket could not be opened, or the socket could not bind the
specified local port.
close
public void close()
- Closes this datagram socket.
finalize
protected void finalize()
- Ensures that this socket is closed if there are no longer any references to
this socket.
- Overrides:
- finalize in class Object (I-§1.12.4).
getLocalPort
public int getLocalPort()
- Returns:
- the port number on the local host to which this socket is bound.
receive
public void receive(DatagramPacket p)
throws IOException
- Receives a datagram packet from this socket. When this method returns,
the DatagramPacket's buffer is filled with the data received. The datagram
packet also contains the sender's IP address, and the port number on the
sender's machine.
- This method blocks until a datagram is received. The length field of the datagram packet object contains the length of the received message. If the
message is longer than the buffer length, the message is truncated.
- Parameters:
p
-
the DatagramPacket into which to place the incoming data
- Throws
- IOException (I-§2.29)
- If an I/O error occurs.
send
public void send(DatagramPacket p)
throws IOException
- Sends a datagram packet from this socket. The DatagramPacket (I-§4.2)
includes information indicating the data to be sent, its length, the IP
address of the remote host, and the port number on the remote host.
- Parameters:
p
-
the DatagramPacket to be sent
- Throws
- IOException (I-§2.29)
- If an I/O error occurs.
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Java API Document (HTML generated by dkramer on April 22, 1996)
Copyright © 1996 Sun Microsystems, Inc.
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Please send any comments or corrections to doug.kramer@sun.com