Class DatagramPacket
- java.lang.Object
-
- java.net.DatagramPacket
public final class DatagramPacket extends Object
This class represents a datagram packet.
Datagram packets are used to implement a connectionless packet delivery service. Each message is routed from one machine to another based solely on information contained within that packet. Multiple packets sent from one machine to another might be routed differently, and might arrive in any order. Packet delivery is not guaranteed.
- Since:
- 1.0
Constructor Summary
Constructor | Description |
---|---|
DatagramPacket(byte[] buf,
int length) | Constructs a |
DatagramPacket(byte[] buf,
int offset,
int length) | Constructs a |
DatagramPacket(byte[] buf,
int offset,
int length,
InetAddress address,
int port) | Constructs a datagram packet for sending packets of length |
DatagramPacket(byte[] buf,
int offset,
int length,
SocketAddress address) | Constructs a datagram packet for sending packets of length |
DatagramPacket(byte[] buf,
int length,
InetAddress address,
int port) | Constructs a datagram packet for sending packets of length |
DatagramPacket(byte[] buf,
int length,
SocketAddress address) | Constructs a datagram packet for sending packets of length |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
InetAddress | getAddress() | Returns the IP address of the machine to which this datagram is being sent or from which the datagram was received. |
byte[] | getData() | Returns the data buffer. |
int | getLength() | Returns the length of the data to be sent or the length of the data received. |
int | getOffset() | Returns the offset of the data to be sent or the offset of the data received. |
int | getPort() | Returns the port number on the remote host to which this datagram is being sent or from which the datagram was received. |
SocketAddress | getSocketAddress() | Gets the SocketAddress (usually IP address + port number) of the remote host that this packet is being sent to or is coming from. |
void | setAddress(InetAddress iaddr) | Sets the IP address of the machine to which this datagram is being sent. |
void | setData(byte[] buf) | Set the data buffer for this packet. |
void | setData(byte[] buf,
int offset,
int length) | Set the data buffer for this packet. |
void | setLength(int length) | Set the length for this packet. |
void | setPort(int iport) | Sets the port number on the remote host to which this datagram is being sent. |
void | setSocketAddress(SocketAddress address) | Sets the SocketAddress (usually IP address + port number) of the remote host to which this datagram is being sent. |
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructor Detail
DatagramPacket
public DatagramPacket(byte[] buf, int offset, int length)
Constructs a DatagramPacket
for receiving packets of length length
, specifying an offset into the buffer.
The length
argument must be less than or equal to buf.length
.
- Parameters:
-
buf
- buffer for holding the incoming datagram. -
offset
- the offset for the buffer -
length
- the number of bytes to read. - Since:
- 1.2
DatagramPacket
public DatagramPacket(byte[] buf, int length)
Constructs a DatagramPacket
for receiving packets of length length
.
The length
argument must be less than or equal to buf.length
.
- Parameters:
-
buf
- buffer for holding the incoming datagram. -
length
- the number of bytes to read.
DatagramPacket
public DatagramPacket(byte[] buf, int offset, int length, InetAddress address, int port)
Constructs a datagram packet for sending packets of length length
with offset ioffset
to the specified port number on the specified host. The length
argument must be less than or equal to buf.length
.
- Parameters:
-
buf
- the packet data. -
offset
- the packet data offset. -
length
- the packet data length. -
address
- the destination address. -
port
- the destination port number. - Since:
- 1.2
- See Also:
InetAddress
DatagramPacket
public DatagramPacket(byte[] buf, int offset, int length, SocketAddress address)
Constructs a datagram packet for sending packets of length length
with offset ioffset
to the specified port number on the specified host. The length
argument must be less than or equal to buf.length
.
- Parameters:
-
buf
- the packet data. -
offset
- the packet data offset. -
length
- the packet data length. -
address
- the destination socket address. - Throws:
-
IllegalArgumentException
- if address type is not supported - Since:
- 1.4
- See Also:
InetAddress
DatagramPacket
public DatagramPacket(byte[] buf, int length, InetAddress address, int port)
Constructs a datagram packet for sending packets of length length
to the specified port number on the specified host. The length
argument must be less than or equal to buf.length
.
- Parameters:
-
buf
- the packet data. -
length
- the packet length. -
address
- the destination address. -
port
- the destination port number. - See Also:
InetAddress
DatagramPacket
public DatagramPacket(byte[] buf, int length, SocketAddress address)
Constructs a datagram packet for sending packets of length length
to the specified port number on the specified host. The length
argument must be less than or equal to buf.length
.
- Parameters:
-
buf
- the packet data. -
length
- the packet length. -
address
- the destination address. - Throws:
-
IllegalArgumentException
- if address type is not supported - Since:
- 1.4
- See Also:
InetAddress
Method Detail
getAddress
public InetAddress getAddress()
Returns the IP address of the machine to which this datagram is being sent or from which the datagram was received.
- Returns:
- the IP address of the machine to which this datagram is being sent or from which the datagram was received.
- See Also:
-
InetAddress
,setAddress(java.net.InetAddress)
getPort
public int getPort()
Returns the port number on the remote host to which this datagram is being sent or from which the datagram was received.
- Returns:
- the port number on the remote host to which this datagram is being sent or from which the datagram was received.
- See Also:
setPort(int)
getData
public byte[] getData()
Returns the data buffer. The data received or the data to be sent starts from the offset
in the buffer, and runs for length
long.
- Returns:
- the buffer used to receive or send data
- See Also:
setData(byte[], int, int)
getOffset
public int getOffset()
Returns the offset of the data to be sent or the offset of the data received.
- Returns:
- the offset of the data to be sent or the offset of the data received.
- Since:
- 1.2
getLength
public int getLength()
Returns the length of the data to be sent or the length of the data received.
- Returns:
- the length of the data to be sent or the length of the data received.
- See Also:
setLength(int)
setData
public void setData(byte[] buf, int offset, int length)
Set the data buffer for this packet. This sets the data, length and offset of the packet.
- Parameters:
-
buf
- the buffer to set for this packet -
offset
- the offset into the data -
length
- the length of the data and/or the length of the buffer used to receive data - Throws:
-
NullPointerException
- if the argument is null - Since:
- 1.2
- See Also:
-
getData()
,getOffset()
,getLength()
setAddress
public void setAddress(InetAddress iaddr)
Sets the IP address of the machine to which this datagram is being sent.
- Parameters:
-
iaddr
- theInetAddress
- Since:
- 1.1
- See Also:
getAddress()
setPort
public void setPort(int iport)
Sets the port number on the remote host to which this datagram is being sent.
- Parameters:
-
iport
- the port number - Since:
- 1.1
- See Also:
getPort()
setSocketAddress
public void setSocketAddress(SocketAddress address)
Sets the SocketAddress (usually IP address + port number) of the remote host to which this datagram is being sent.
- Parameters:
-
address
- theSocketAddress
- Throws:
-
IllegalArgumentException
- if address is null or is a SocketAddress subclass not supported by this socket - Since:
- 1.4
- See Also:
getSocketAddress()
getSocketAddress
public SocketAddress getSocketAddress()
Gets the SocketAddress (usually IP address + port number) of the remote host that this packet is being sent to or is coming from.
- Returns:
- the
SocketAddress
- Since:
- 1.4
- See Also:
setSocketAddress(java.net.SocketAddress)
setData
public void setData(byte[] buf)
Set the data buffer for this packet. With the offset of this DatagramPacket set to 0, and the length set to the length of buf
.
- Parameters:
-
buf
- the buffer to set for this packet. - Throws:
-
NullPointerException
- if the argument is null. - Since:
- 1.1
- See Also:
-
getLength()
,getData()
setLength
public void setLength(int length)
Set the length for this packet. The length of the packet is the number of bytes from the packet's data buffer that will be sent, or the number of bytes of the packet's data buffer that will be used for receiving data. The length must be lesser or equal to the offset plus the length of the packet's buffer.
- Parameters:
-
length
- the length to set for this packet. - Throws:
-
IllegalArgumentException
- if the length is negative of if the length is greater than the packet's data buffer length. - Since:
- 1.1
- See Also:
-
getLength()
,setData(byte[], int, int)