javax.microedition.io
Interface Datagram

All Superinterfaces:

DataInput, DataOutput

public interface Datagram

extends DataInput, DataOutput

This is the generic datagram interface. It represents an object that will act as the holder of data to be send or received from a datagram connection. The DataInput and DataOutput interfaces are extended by this interface to provide a simple way to read and write binary data in and out of the datagram buffer. A special function reset() may be called to reset the read/write point to the beginning of the buffer.

Method Summary

String	getAddress() Get the address in the datagram
byte[]	getData() Get the buffer
int	getLength() Get the length
int	getOffset() Get the offset
void	reset() Reset the read/write pointer and zeros the offset and length parameters.
void	setAddress(Datagram reference) Set datagram address, copying the address from another datagram.
void	setAddress(String addr) Set datagram address.
void	setData(byte[] buffer, int offset, int len) Set the buffer, offset and length
void	setLength(int len) Set the length

Methods inherited from interface java.io.DataInput

readBoolean, readByte, readChar, readDouble, readFloat, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedShort, readUTF, skipBytes

Methods inherited from interface java.io.DataOutput

write, write, write, writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeDouble, writeFloat, writeInt, writeLong, writeShort, writeUTF

Method Detail

getAddress

public String getAddress()

Get the address in the datagram

Returns:

the address in string form, or null if no address was set

getData

public byte[] getData()

Get the buffer

Returns:

the data buffer

getLength

public int getLength()

Get the length

Returns:

the length of the data

getOffset

public int getOffset()

Get the offset

Returns:

the offset into the data buffer

setAddress

public void setAddress(String addr)
                throws IOException

Set datagram address. The parameter string describing the target of the datagram takes the form:

     {protocol}:{target}
 

E.g. The "target" can be "//{host}:{port}" (but is not necessarily limited to this.)
So in this example a datagram connection for sending to a server could be addressed as so:

     datagram://123.456.789.12:1234
 

Note that if the address of a datagram is not specified, then it defaults to that of the connection.

Parameters:

addr - the new target address as a URL

Throws:

IllegalArgumentException - if the address is not valid

setAddress

public void setAddress(Datagram reference)

Set datagram address, copying the address from another datagram.

Parameters:

reference - the datagram who's address will be copied as the new target address for this datagram.

Throws:

IllegalArgumentException - if the address is not valid

setLength

public void setLength(int len)

Set the length

Parameters:

len - the new length of the data

Throws:

IllegalArgumentException - if the length is negative or larger than the buffer

setData

public void setData(byte[] buffer,
                    int offset,
                    int len)

Set the buffer, offset and length

Parameters:

addr - the data buffer

offset - the offset into the data buffer

len - the length of the data in the buffer

Throws:

IllegalArgumentException - if the length or offset fall outside the buffer

reset

public void reset()

Reset the read/write pointer and zeros the offset and length parameters.