aim4.msg.udp
Class UdpHeader

java.lang.Object
  aim4.msg.udp.UdpHeader

public class UdpHeader
extends Object

Small header included in all UDP messages sent to/from the real car.

Nested Class Summary

static class

UdpHeader.UdpMessageType The message type.

Field Summary

static int	LENGTH The size of a UDP header (in bytes)
static int	MAX_MESSENGE_PACKAGE_LENGTH The maximum length of a message package including the header (in bytes)

Constructor Summary

UdpHeader(DataInputStream dis)
Construct the header given a DataInputStream wrapped around a DatagramPacket received over UDP from the real car.

UdpHeader(float currentTime, UdpHeader.UdpMessageType messageType)
Create a header for a particular message type

Method Summary

static int	computeChecksum(byte[] data) Compute the check sum for an array of bytes.
int	getChecksum() Get the check sum.
UdpHeader.UdpMessageType	getMessageType() Get the message type.
float	getTimestamp() Get the time stamp.
String	toString()
DataOutputStream	writeToDataOutputStream(DataOutputStream dos) Write the data header to an I/O stream.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

MAX_MESSENGE_PACKAGE_LENGTH

public static final int MAX_MESSENGE_PACKAGE_LENGTH

The maximum length of a message package including the header (in bytes)

See Also:

Constant Field Values

LENGTH

public static final int LENGTH

The size of a UDP header (in bytes)

See Also:

Constant Field Values

Constructor Detail

UdpHeader

public UdpHeader(DataInputStream dis)
          throws IOException

Construct the header given a DataInputStream wrapped around a DatagramPacket received over UDP from the real car.

Parameters:

dis - The DataInputStream.

Throws:

IOException

UdpHeader

public UdpHeader(float currentTime,
                 UdpHeader.UdpMessageType messageType)

Create a header for a particular message type

Parameters:

currentTime - the current time

messageType - the message type

Method Detail

getTimestamp

public float getTimestamp()

Get the time stamp.

Returns:

the timestamp

getMessageType

public UdpHeader.UdpMessageType getMessageType()

Get the message type.

Returns:

the message type

getChecksum

public int getChecksum()

Get the check sum.

Returns:

the check sum

writeToDataOutputStream

public DataOutputStream writeToDataOutputStream(DataOutputStream dos)
                                         throws IOException

Write the data header to an I/O stream.

Parameters:

dos - the I/O stream

Returns:

the I/O stream

Throws:

IOException

computeChecksum

public static int computeChecksum(byte[] data)

Compute the check sum for an array of bytes.

Parameters:

data - the array of bytes

Returns:

the check sum

toString

public String toString()

Overrides:

toString in class Object