- 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 SummaryConstructors Constructor Description DatagramPacket(byte[] buf, int length)Constructs aDatagramPacketfor receiving packets of lengthlength.DatagramPacket(byte[] buf, int offset, int length)Constructs aDatagramPacketfor receiving packets of lengthlength, specifying an offset into the buffer.DatagramPacket(byte[] buf, int offset, int length, InetAddress address, int port)Constructs a datagram packet for sending packets of lengthlengthwith offsetioffsetto the specified port number on the specified host.DatagramPacket(byte[] buf, int offset, int length, SocketAddress address)Constructs a datagram packet for sending packets of lengthlengthwith offsetioffsetto the specified port number on the specified host.DatagramPacket(byte[] buf, int length, InetAddress address, int port)Constructs a datagram packet for sending packets of lengthlengthto the specified port number on the specified host.DatagramPacket(byte[] buf, int length, SocketAddress address)Constructs a datagram packet for sending packets of lengthlengthto the specified port number on the specified host.
 - 
Method SummaryAll Methods Instance Methods Concrete Methods Modifier and Type Method Description InetAddressgetAddress()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.intgetLength()Returns the length of the data to be sent or the length of the data received.intgetOffset()Returns the offset of the data to be sent or the offset of the data received.intgetPort()Returns the port number on the remote host to which this datagram is being sent or from which the datagram was received.SocketAddressgetSocketAddress()Gets the SocketAddress (usually IP address + port number) of the remote host that this packet is being sent to or is coming from.voidsetAddress(InetAddress iaddr)Sets the IP address of the machine to which this datagram is being sent.voidsetData(byte[] buf)Set the data buffer for this packet.voidsetData(byte[] buf, int offset, int length)Set the data buffer for this packet.voidsetLength(int length)Set the length for this packet.voidsetPort(int iport)Sets the port number on the remote host to which this datagram is being sent.voidsetSocketAddress(SocketAddress address)Sets the SocketAddress (usually IP address + port number) of the remote host to which this datagram is being sent.
 
- 
- 
- 
Constructor Detail- 
DatagramPacketpublic DatagramPacket(byte[] buf, int offset, int length)Constructs aDatagramPacketfor receiving packets of lengthlength, specifying an offset into the buffer.The lengthargument must be less than or equal tobuf.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
 
 - 
DatagramPacketpublic DatagramPacket(byte[] buf, int length)Constructs aDatagramPacketfor receiving packets of lengthlength.The lengthargument must be less than or equal tobuf.length.- Parameters:
- buf- buffer for holding the incoming datagram.
- length- the number of bytes to read.
 
 - 
DatagramPacketpublic DatagramPacket(byte[] buf, int offset, int length, InetAddress address, int port)Constructs a datagram packet for sending packets of lengthlengthwith offsetioffsetto the specified port number on the specified host. Thelengthargument must be less than or equal tobuf.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
 
 - 
DatagramPacketpublic DatagramPacket(byte[] buf, int offset, int length, SocketAddress address)Constructs a datagram packet for sending packets of lengthlengthwith offsetioffsetto the specified port number on the specified host. Thelengthargument must be less than or equal tobuf.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
 
 - 
DatagramPacketpublic DatagramPacket(byte[] buf, int length, InetAddress address, int port)Constructs a datagram packet for sending packets of lengthlengthto the specified port number on the specified host. Thelengthargument must be less than or equal tobuf.length.- Parameters:
- buf- the packet data.
- length- the packet length.
- address- the destination address.
- port- the destination port number.
- See Also:
- InetAddress
 
 - 
DatagramPacketpublic DatagramPacket(byte[] buf, int length, SocketAddress address)Constructs a datagram packet for sending packets of lengthlengthto the specified port number on the specified host. Thelengthargument must be less than or equal tobuf.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- 
getAddresspublic 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)
 
 - 
getPortpublic 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)
 
 - 
getDatapublic byte[] getData() Returns the data buffer. The data received or the data to be sent starts from theoffsetin the buffer, and runs forlengthlong.- Returns:
- the buffer used to receive or send data
- See Also:
- setData(byte[], int, int)
 
 - 
getOffsetpublic 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
 
 - 
getLengthpublic 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)
 
 - 
setDatapublic 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()
 
 - 
setAddresspublic void setAddress(InetAddress iaddr) Sets the IP address of the machine to which this datagram is being sent.- Parameters:
- iaddr- the- InetAddress
- Since:
- 1.1
- See Also:
- getAddress()
 
 - 
setPortpublic 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()
 
 - 
setSocketAddresspublic 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- the- SocketAddress
- Throws:
- IllegalArgumentException- if address is null or is a SocketAddress subclass not supported by this socket
- Since:
- 1.4
- See Also:
- getSocketAddress()
 
 - 
getSocketAddresspublic 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)
 
 - 
setDatapublic 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 ofbuf.- Parameters:
- buf- the buffer to set for this packet.
- Throws:
- NullPointerException- if the argument is null.
- Since:
- 1.1
- See Also:
- getLength(),- getData()
 
 - 
setLengthpublic 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)
 
 
- 
 
-