Constructor Detail

• DelegatingDatagramSocket

  DelegatingDatagramSocket()

  Initializes a new DelegatingDatagramSocket instance and binds it to any available port on the local host machine.

• DelegatingDatagramSocket

  DelegatingDatagramSocket(DatagramSocket delegate)

  Initializes a new DelegatingDatagramSocket instance which to implement the DatagramSocket functionality by delegating to a specific DatagramSocket.

  Parameters:

  delegate - the DatagramSocket to which the new instance is to delegate

• DelegatingDatagramSocket

  DelegatingDatagramSocket(int port)

  Initializes a new DelegatingDatagramSocket instance and binds it to the specified port on the local host machine.

  Parameters:

  port - the port to bind the new socket to

• DelegatingDatagramSocket

  DelegatingDatagramSocket(int port, InetAddress laddr)

  Initializes a new DelegatingDatagramSocket instance bound to the specified local address.

  Parameters:

  port - the local port to bind the new socket to

  laddr - the local address to bind the new socket to

• DelegatingDatagramSocket

  DelegatingDatagramSocket(SocketAddress bindaddr)

  Creates a datagram socket, bound to the specified local socket address.

  Parameters:

  bindaddr - local socket address to bind, or null for an unbound socket

• DelegatingDatagramSocket

  DelegatingDatagramSocket(DatagramSocket delegate, SocketAddress address)

  Initializes a new DelegatingDatagramSocket instance which implements the DatagramSocket functionality.

  Parameters:

  delegate - the DatagramSocket to which the new instance is to delegate.

  address - The local socket address to bind, or null for an unbound socket.

Method Detail

• setDefaultReceiveBufferSize

   static void setDefaultReceiveBufferSize(int size)

  Specifies a default receive buffer size for the underlying sockets. This function must be called before using the DelegatingDatagramSocket constructor. The size must be greater than 0 to be effective.

  Parameters:

  size - the size to which to set the receive buffer size.

• setDefaultDelegateFactory

   static void setDefaultDelegateFactory(DatagramSocketFactory factory)

  If a factory is provided, then any new instances of DelegatingDatagramSocket will automatically use a socket from the factory instead of the super class. If this method is used, the factory class needs to ensure the socket objects are properly constructed and initialized - in particular, any default receive buffer size specified through DelegatingDatagramSocket#setDefaultReceiveBufferSize() won't automatically be applied to sockets obtain from the factory.

  Parameters:

  factory - The factory assigned to generates the new DatagramSocket for each new DelegatingDatagramSocket which do not use a delegate socket.

• bind

   void bind(SocketAddress addr)

  Binds this DatagramSocket to a specific address and port.

  If the address is null, then the system will pick up an ephemeral port and a valid local address to bind the socket.

  Parameters:

  addr - the address and port to bind to

• close

   void close()

  Closes this datagram socket.

  Any thread currently blocked in receive upon this socket will throw a SocketException.

• connect

   void connect(InetAddress address, int port)

  Connects the socket to a remote address for this socket. When a socket is connected to a remote address, packets may only be sent to or received from that address. By default a datagram socket is not connected.

  If the remote destination to which the socket is connected does not exist, or is otherwise unreachable, and if an ICMP destination unreachable packet has been received for that address, then a subsequent call to send or receive may throw a PortUnreachableException. Note, there is no guarantee that the exception will be thrown.

  Parameters:

  address - the remote address for the socket

  port - the remote port for the socket

• connect

   void connect(SocketAddress addr)

  Connects this socket to a remote socket address.

  Parameters:

  addr - the remote address

• disconnect

   void disconnect()

  Disconnects the socket. This does nothing if the socket is not connected.

• getBroadcast

   boolean getBroadcast()

  Tests if SO_BROADCAST is enabled.

• getChannel

   DatagramChannel getChannel()

  Returns the unique DatagramChannel object associated with this datagram socket, if any.

  A datagram socket will have a channel if, and only if, the channel itself was created via the open method

• getInetAddress

   InetAddress getInetAddress()

  Returns the address to which this socket is connected. Returns null if the socket is not connected.

• getLocalAddress

   InetAddress getLocalAddress()

  Gets the local address to which the socket is bound.

  If there is a security manager, its checkConnect method is first called with the host address and -1 as its arguments to see if the operation is allowed.

• getLocalPort

   int getLocalPort()

  Returns the port number on the local host to which this socket is bound.

• getLocalSocketAddress

   SocketAddress getLocalSocketAddress()

  Returns the address of the endpoint this socket is bound to, or null if it is not bound yet.

• getPort

   int getPort()

  Returns the port for this socket. Returns -1 if the socket is not connected.

• getReceiveBufferSize

   int getReceiveBufferSize()

  Gets the value of the SO_RCVBUF option for this DatagramSocket, that is the buffer size used by the platform for input on this DatagramSocket.

• getRemoteSocketAddress

   SocketAddress getRemoteSocketAddress()

  Returns the address of the endpoint this socket is connected to, or null if it is unconnected.

• getReuseAddress

   boolean getReuseAddress()

  Tests if SO_REUSEADDR is enabled.

• getSendBufferSize

   int getSendBufferSize()

  Gets the value of the SO_SNDBUF option for this DatagramSocket, that is the buffer size used by the platform for output on this DatagramSocket.

• getSoTimeout

   int getSoTimeout()

  Retrieves setting for SO_TIMEOUT. Zero returned implies that the option is disabled (i.e., timeout of infinity).

• getTrafficClass

   int getTrafficClass()

  Gets the traffic class or type-of-service in the IP datagram header for packets sent from this DatagramSocket.

  As the underlying network implementation may ignore the traffic class or type-of-service set using setTrafficClass this method may return a different value than was previously set using the setTrafficClass method on this DatagramSocket.

• isBound

   boolean isBound()

  Returns the binding state of the socket.

• isClosed

   boolean isClosed()

  Returns whether the socket is closed or not.

• isConnected

   boolean isConnected()

  Returns the connection state of the socket.

• receive

   void receive(DatagramPacket p)

  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 packet's length, the message is truncated.

  If there is a security manager, a packet cannot be received if the security manager's checkAccept method does not allow it.

  Parameters:

  p - the DatagramPacket into which to place the incoming data

• send

   void send(DatagramPacket p)

  Sends a datagram packet from this socket. The DatagramPacket 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.

  If there is a security manager, and the socket is not currently connected to a remote address, this method first performs some security checks. First, if p.getAddress().isMulticastAddress() is true, this method calls the security manager's checkMulticast method with p.getAddress() as its argument. If the evaluation of that expression is false, this method instead calls the security manager's checkConnect method with arguments p.getAddress().getHostAddress() and p.getPort(). Each call to a security manager method could result in a SecurityException if the operation is not allowed.

  Parameters:

  p - the DatagramPacket to be sent

• setBroadcast

   void setBroadcast(boolean on)

  Enables/disables SO_BROADCAST.

  Parameters:

  on - whether or not to have broadcast turned on

• setReceiveBufferSize

   void setReceiveBufferSize(int size)

  Sets the SO_RCVBUF option to the specified value for this DatagramSocket. The SO_RCVBUF option is used by the network implementation as a hint to size the underlying network I/O buffers. The SO_RCVBUF setting may also be used by the network implementation to determine the maximum size of the packet that can be received on this socket.

  Because SO_RCVBUF is a hint, applications that want to verify what size the buffers were set to should call getReceiveBufferSize.

  Parameters:

  size - the size to which to set the receive buffer size.

• setReuseAddress

   void setReuseAddress(boolean on)

  Enables/disables the SO_REUSEADDR socket option.

  Parameters:

  on - whether to enable or disable the SO_REUSEADDR socket option

• setSendBufferSize

   void setSendBufferSize(int size)

  Sets the SO_SNDBUF option to the specified value for this DatagramSocket. The SO_SNDBUF option is used by the network implementation as a hint to size the underlying network I/O buffers. The SO_SNDBUF setting may also be used by the network implementation to determine the maximum size of the packet that can be sent on this socket.

  As SO_SNDBUF is a hint, applications that want to verify what size the buffer is should call getSendBufferSize.

  Increasing the buffer size may allow multiple outgoing packets to be queued by the network implementation when the send rate is high.

  Parameters:

  size - the size to which to set the send buffer size.

• setSoTimeout

   void setSoTimeout(int timeout)

  Enables/disables SO_TIMEOUT with the specified timeout, in milliseconds. With this option set to a non-zero timeout, a call to receive for this DatagramSocket will block for only this amount of time. If the timeout expires, a SocketTimeoutException is raised, though the DatagramSocket is still valid. The option must be enabled prior to entering the blocking operation to have effect. The timeout must be greater than zero. A timeout of zero is interpreted as an infinite timeout.

  Parameters:

  timeout - the specified timeout in milliseconds

• setTrafficClass

   void setTrafficClass(int tc)

  Sets traffic class or type-of-service octet in the IP datagram header for datagrams sent from this DatagramSocket. As the underlying network implementation may ignore this value applications should consider it a hint.

  Parameters:

  tc - an int value for the bitset