DatagramSocket

java.lang.Object
- java.net.DatagramSocket

```
public class DatagramSocket
extends Object
```
This class models a connectionless datagram socket that sends individual packets of data across the network. In the TCP/IP world, this means UDP. Datagram packets do not have guaranteed delivery, or any guarantee about the order the data will be received on the remote host.

Author:

Aaron M. Renn (arenn@urbanophile.com), Warren Levy (warrenl@cygnus.com)

Constructor Summary

Constructors
Constructor and Description
`DatagramSocket()` Initializes a new instance of `DatagramSocket` that binds to a random port and every address on the local machine.
`DatagramSocket(int port)` Initializes a new instance of `DatagramSocket` that binds to the specified port and every address on the local machine.
`DatagramSocket(int port, InetAddress addr)` Initializes a new instance of `DatagramSocket` that binds to the specified local port and address.
`DatagramSocket(SocketAddress address)` Initializes a new instance of `DatagramSocket` that binds to the specified local port and address.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`bind(SocketAddress address)` Binds the socket to the given socket address.
`void`	`close()` Closes this datagram socket.
`void`	`connect(InetAddress address, int port)` This method connects this socket to the specified address and port.
`void`	`connect(SocketAddress address)` Connects the datagram socket to a specified socket address.
`void`	`disconnect()` This method disconnects this socket from the address/port it was connected to.
`boolean`	`getBroadcast()` Checks if SO_BROADCAST is enabled
`InetAddress`	`getInetAddress()` This method returns the remote address to which this socket is connected.
`InetAddress`	`getLocalAddress()` Returns the local address this datagram socket is bound to.
`int`	`getLocalPort()` Returns the local port this socket is bound to.
`SocketAddress`	`getLocalSocketAddress()` Returns the local SocketAddress this socket is bound to.
`int`	`getPort()` This method returns the remote port to which this socket is connected.
`int`	`getReceiveBufferSize()` This method returns the value of the system level socket option SO_RCVBUF, which is used by the operating system to tune buffer sizes for data transfers.
`SocketAddress`	`getRemoteSocketAddress()` Returns the SocketAddress of the host this socket is conneted to or null if this socket is not connected.
`boolean`	`getReuseAddress()` Checks if SO_REUSEADDR is enabled.
`int`	`getSendBufferSize()` This method returns the value of the system level socket option SO_SNDBUF, which is used by the operating system to tune buffer sizes for data transfers.
`int`	`getSoTimeout()` Returns the value of the socket's SO_TIMEOUT setting.
`int`	`getTrafficClass()` Returns the current traffic class
`boolean`	`isBound()` Returns the binding state of the socket.
`boolean`	`isClosed()` Checks if the datagram socket is closed.
`boolean`	`isConnected()` Returns the connection state of the socket.
`void`	`receive(DatagramPacket p)` Reads a datagram packet from the socket.
`void`	`send(DatagramPacket p)` Sends the specified packet.
`void`	`setBroadcast(boolean enable)` Enables/Disables SO_BROADCAST
`void`	`setReceiveBufferSize(int size)` This method sets the value for the system level socket option SO_RCVBUF to the specified value.
`void`	`setReuseAddress(boolean on)` Enables/Disables SO_REUSEADDR.
`void`	`setSendBufferSize(int size)` This method sets the value for the system level socket option SO_SNDBUF to the specified value.
`void`	`setSoTimeout(int timeout)` Sets the value of the socket's SO_TIMEOUT value.
`void`	`setTrafficClass(int tc)` Sets the traffic class value

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - DatagramSocket
```
public DatagramSocket()
               throws SocketException
```
    Initializes a new instance of DatagramSocket that binds to a random port and every address on the local machine.
    
    Throws:
    
    SocketException - If an error occurs.
  - DatagramSocket
```
public DatagramSocket(int port)
               throws SocketException
```
    Initializes a new instance of DatagramSocket that binds to the specified port and every address on the local machine.
    
    Parameters:
    
    port - The local port number to bind to.
    
    Throws:
    
    SocketException - If an error occurs.
  - DatagramSocket
```
public DatagramSocket(int port,
                      InetAddress addr)
               throws SocketException
```
    Initializes a new instance of DatagramSocket that binds to the specified local port and address.
    
    Parameters:
    
    port - The local port number to bind to.
    
    addr - The local address to bind to.
    
    Throws:
    
    SocketException - If an error occurs.
  - DatagramSocket
```
public DatagramSocket(SocketAddress address)
               throws SocketException
```
    Initializes a new instance of DatagramSocket that binds to the specified local port and address.
    
    Parameters:
    
    address - The local address and port number to bind to.
    
    Throws:
    
    SocketException - If an error occurs.
    
    Since:
    
    1.4
- Method Detail
  - bind
```
public void bind(SocketAddress address)
          throws SocketException
```
    Binds the socket to the given socket address.
    
    Parameters:
    
    address - The socket address to bind to.
    
    Throws:
    
    SocketException - If an error occurs.
    
    IllegalArgumentException - If address type is not supported.
    
    Since:
    
    1.4
  - close
```
public void close()
```
    Closes this datagram socket.
  - connect
```
public void connect(InetAddress address,
                    int port)
             throws SocketException,
                    IllegalArgumentException
```
    This method connects this socket to the specified address and port. When a datagram socket is connected, it will only send or receive packets to and from the host to which it is connected. A multicast socket that is connected may only send and not receive packets.
    
    Parameters:
    
    address - The address to connect this socket to.
    
    port - The port to connect this socket to.
    
    Throws:
    
    SocketException
    
    IllegalArgumentException - If address or port are invalid.
    
    Since:
    
    1.2
  - connect
```
public void connect(SocketAddress address)
             throws SocketException
```
    Connects the datagram socket to a specified socket address.
    
    Parameters:
    
    address - The socket address to connect to.
    
    Throws:
    
    SocketException - If an error occurs.
    
    IllegalArgumentException - If address type is not supported.
    
    Since:
    
    1.4
  - disconnect
```
public void disconnect()
```
    This method disconnects this socket from the address/port it was connected to. If the socket was not connected in the first place, this method does nothing.
    
    Since:
    
    1.2
  - getBroadcast
```
public boolean getBroadcast()
                     throws SocketException
```
    Checks if SO_BROADCAST is enabled
    
    Returns:
    
    Whether SO_BROADCAST is set
    
    Throws:
    
    SocketException - If an error occurs
    
    Since:
    
    1.4
  - getInetAddress
```
public InetAddress getInetAddress()
```
    This method returns the remote address to which this socket is connected. If this socket is not connected, then this method will return null.
    
    Returns:
    
    The remote address.
    
    Since:
    
    1.2
  - getLocalAddress
```
public InetAddress getLocalAddress()
```
    Returns the local address this datagram socket is bound to.
    
    Returns:
    
    The local address is the socket is bound or null
    
    Since:
    
    1.1
  - getLocalPort
```
public int getLocalPort()
```
    Returns the local port this socket is bound to.
    
    Returns:
    
    The local port number.
  - getLocalSocketAddress
```
public SocketAddress getLocalSocketAddress()
```
    Returns the local SocketAddress this socket is bound to.
    
    Returns:
    
    The local SocketAddress or null if the socket is not bound.
    
    Since:
    
    1.4
  - getPort
```
public int getPort()
```
    This method returns the remote port to which this socket is connected. If this socket is not connected, then this method will return -1.
    
    Returns:
    
    The remote port.
    
    Since:
    
    1.2
  - getReceiveBufferSize
```
public int getReceiveBufferSize()
                         throws SocketException
```
    This method returns the value of the system level socket option SO_RCVBUF, which is used by the operating system to tune buffer sizes for data transfers.
    
    Returns:
    
    The receive buffer size.
    
    Throws:
    
    SocketException - If an error occurs.
    
    Since:
    
    1.2
  - getRemoteSocketAddress
```
public SocketAddress getRemoteSocketAddress()
```
    Returns the SocketAddress of the host this socket is conneted to or null if this socket is not connected.
    
    Returns:
    
    The socket address of the remote host if connected or null
    
    Since:
    
    1.4
  - getReuseAddress
```
public boolean getReuseAddress()
                        throws SocketException
```
    Checks if SO_REUSEADDR is enabled.
    
    Returns:
    
    True if SO_REUSEADDR is set on the socket, false otherwise.
    
    Throws:
    
    SocketException - If an error occurs.
    
    Since:
    
    1.4
  - getSendBufferSize
```
public int getSendBufferSize()
                      throws SocketException
```
    This method returns the value of the system level socket option SO_SNDBUF, which is used by the operating system to tune buffer sizes for data transfers.
    
    Returns:
    
    The send buffer size.
    
    Throws:
    
    SocketException - If an error occurs.
    
    Since:
    
    1.2
  - getSoTimeout
```
public int getSoTimeout()
                 throws SocketException
```
    Returns the value of the socket's SO_TIMEOUT setting. If this method returns 0 then SO_TIMEOUT is disabled.
    
    Returns:
    
    The current timeout in milliseconds.
    
    Throws:
    
    SocketException - If an error occurs.
    
    Since:
    
    1.1
  - getTrafficClass
```
public int getTrafficClass()
                    throws SocketException
```
    Returns the current traffic class
    
    Returns:
    
    The current traffic class.
    
    Throws:
    
    SocketException - If an error occurs
    
    Since:
    
    1.4
    
    See Also:
    
    setTrafficClass(int tc)
  - isBound
```
public boolean isBound()
```
    Returns the binding state of the socket.
    
    Returns:
    
    True if socket bound, false otherwise.
    
    Since:
    
    1.4
  - isClosed
```
public boolean isClosed()
```
    Checks if the datagram socket is closed.
    
    Returns:
    
    True if socket is closed, false otherwise.
    
    Since:
    
    1.4
  - isConnected
```
public boolean isConnected()
```
    Returns the connection state of the socket.
    
    Returns:
    
    True if socket is connected, false otherwise.
    
    Since:
    
    1.4
  - receive
```
public void receive(DatagramPacket p)
             throws IOException
```
    Reads a datagram packet from the socket. Note that this method will block until a packet is received from the network. On return, the passed in DatagramPacket is populated with the data received and all the other information about the packet.
    
    Parameters:
    
    p - A DatagramPacket for storing the data
    
    Throws:
    
    IOException - If an error occurs.
    
    SocketTimeoutException - If setSoTimeout was previously called and the timeout has expired.
  - send
```
public void send(DatagramPacket p)
          throws IOException
```
    Sends the specified packet. The host and port to which the packet are to be sent should be set inside the packet.
    
    Parameters:
    
    p - The datagram packet to send.
    
    Throws:
    
    IOException - If an error occurs.
  - setBroadcast
```
public void setBroadcast(boolean enable)
                  throws SocketException
```
    Enables/Disables SO_BROADCAST
    
    Parameters:
    
    enable - True if SO_BROADCAST should be enabled, false otherwise.
    
    Throws:
    
    SocketException - If an error occurs
    
    Since:
    
    1.4
  - setReceiveBufferSize
```
public void setReceiveBufferSize(int size)
                          throws SocketException
```
    This method sets the value for the system level socket option SO_RCVBUF to the specified value. Note that valid values for this option are specific to a given operating system.
    
    Parameters:
    
    size - The new receive buffer size.
    
    Throws:
    
    SocketException - If an error occurs.
    
    IllegalArgumentException - If size is 0 or negative.
    
    Since:
    
    1.2
  - setReuseAddress
```
public void setReuseAddress(boolean on)
                     throws SocketException
```
    Enables/Disables SO_REUSEADDR.
    
    Parameters:
    
    on - Whether or not to have SO_REUSEADDR turned on.
    
    Throws:
    
    SocketException - If an error occurs.
    
    Since:
    
    1.4
  - setSendBufferSize
```
public void setSendBufferSize(int size)
                       throws SocketException
```
    This method sets the value for the system level socket option SO_SNDBUF to the specified value. Note that valid values for this option are specific to a given operating system.
    
    Parameters:
    
    size - The new send buffer size.
    
    Throws:
    
    SocketException - If an error occurs.
    
    IllegalArgumentException - If size is 0 or negative.
    
    Since:
    
    1.2
  - setSoTimeout
```
public void setSoTimeout(int timeout)
                  throws SocketException
```
    Sets the value of the socket's SO_TIMEOUT value. A value of 0 will disable SO_TIMEOUT. Any other value is the number of milliseconds a socket read/write will block before timing out.
    
    Parameters:
    
    timeout - The new SO_TIMEOUT value in milliseconds.
    
    Throws:
    
    SocketException - If an error occurs.
    
    Since:
    
    1.1
  - setTrafficClass
```
public void setTrafficClass(int tc)
                     throws SocketException
```
    Sets the traffic class value
    
    Parameters:
    
    tc - The traffic class
    
    Throws:
    
    SocketException - If an error occurs
    
    IllegalArgumentException - If tc value is illegal
    
    Since:
    
    1.4
    
    See Also:
    
    getTrafficClass()

Class DatagramSocket

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DatagramSocket

DatagramSocket

DatagramSocket

DatagramSocket

Method Detail

bind

close

connect

connect

disconnect

getBroadcast

getInetAddress

getLocalAddress

getLocalPort

getLocalSocketAddress

getPort

getReceiveBufferSize

getRemoteSocketAddress

getReuseAddress

getSendBufferSize

getSoTimeout

getTrafficClass

isBound

isClosed

isConnected

receive

send

setBroadcast

setReceiveBufferSize

setReuseAddress

setSendBufferSize

setSoTimeout

setTrafficClass