dk.i1.diameter
Class Message

Object
  dk.i1.diameter.Message

public class Message
extends Object

A Diameter Message. The Message is a container for the MessageHeader and the AVPs. It supports converting to/from the on-the-wire format, and manipulating the AVPs. The class is lean and mean, and does as little checking as possible.

Example of building a Message:

Message msg = new Message();
msg.hdr.application_id = ProtocolConstants.DIAMETER_APPLICATION_ACCOUNTING;
msg.hdr.command_code = ProtocolConstants.DIAMETER_COMMAND_ACCOUNTING;
msg.hdr.setRequest(true);
msg.hdr.setProxiable(true);
//Add AVPs
...
msg.add(new AVP_UTF8String(ProtocolConstants.DI_USER_NAME,"user@example.net"));
msg.add(new AVP_Unsigned64(ProtocolConstants.DI_ACCOUNTING_INPUT_OCTETS,36758373691049));
...

Message msg ...;
for(AVP avp : msg.subset(ProtocolConstants.DI_FRAMED_IP_ADDRESS)) {
    try {
        InetAddress address = new AVP_Address(avp).queryAddress();
        ..do something useful with the address...
    } catch(InvalidAVPLengthException ex) {
        .. handle when peer sends garbage
    } catch(InvalidAddressTypeException ex) {
        .. handle when peer sends garbage
    }
}
AVP avp_reply_message = msg.find(ProtocolConstants.DI_REPLY_MESSAGE);
if(avp!=null) {
    ..do something sensible with reply-message
}

hdr

public MessageHeader hdr

The message header

Message

public Message()

The default constructor. The header is initialized to default values and the AVP list will be empty

Message

public Message(MessageHeader header)

Construct a message with a specific header. The AVP list will be empty.

Parameters:

header - The message header to use instead of a default one.

Message

public Message(Message msg)

Copy-constructor. Implements a deep copy.

encodeSize

public int encodeSize()

Calculate the size of the message in on-the-wire format

Returns:

The number of bytes the message will use on-the-wire.

encode

public void encode(byte[] b)

Encode the message in on-the-wire format to the specified byte array.

Parameters:

b - The byte array which must be large enough.

encode

public byte[] encode()

Encode the message to on-the-wire format

Returns:

A on-the-wire message byte array

decodeSize

public static int decodeSize(byte[] b,
                             int offset)

Determine the complete size of the message from a on-the-wire byte array. There must be at least 4 bytes available in the array.

Parameters:

b - The byte array

offset - The offset into the byte array where the message is supposed to start.

Returns:

The size (in bytes) of the message

decode

public Message.decode_status decode(byte[] b)

Decode a message from on-the-wire format. Implemented as return decode(b,0,b.length)

Parameters:

b - A byte array which consists of exacly 1 message. Superfluous bytes are not permitted.

Returns:

The result for the decode operation.

decode

public Message.decode_status decode(byte[] b,
                                    int offset,
                                    int bytes)

Decode a message from on-the-wire format. The message is checked to be in valid format and the VPs to be of the correct length etc. Invalid/reserved bits are not checked.

Parameters:

b - A byte array possibly containing a Diameter message

offset - Offset into the array where decoding should start

bytes - The bytes to try to decode

Returns:

The result for the decode operation.

size

public int size()

Return the number of AVPs in the message

ensureCapacity

public void ensureCapacity(int minCapacity)

Ensure that ther is room for at least he specified number of AVPs

get

public AVP get(int index)

Gets the AVP at the specified index (0-based)

clear

public void clear()

Removes all AVPs from the message

add

public void add(AVP avp)

Adds an AVP at the end of the AVP list

add

public void add(int index,
                AVP avp)

Inserts an AVP at the specified posistion (0-based)

remove

public void remove(int index)

Removes the AVP at the specified position (0-based)

avps

public Iterable<AVP> avps()

Returns an Iterable for the AVPs

iterator

public java.util.Iterator<AVP> iterator()

Returns an iterator for the AVP list

iterator

public java.util.Iterator<AVP> iterator(int code)

Returns an iterator for the AVPs with the specified code

iterator

public java.util.Iterator<AVP> iterator(int code,
                                        int vendor_id)

Returns an iterator for the AVPs with the specified code and vendor id

prepareResponse

public void prepareResponse(Message request)

Prepare a response the the supplied request. Implemented as hdr.prepareResponse(request.hdr);

See Also:

MessageHeader.prepareResponse(MessageHeader)

prepareAnswer

public void prepareAnswer(Message request)

Prepare an answer from the specified request header. This is identical to prepareResponse().

Since:

0.9.3

subset

public Iterable<AVP> subset(int code)

Returns a iterable subset of the AVPs. Implemented as

return subset(code,0);

subset

public Iterable<AVP> subset(int code,
                            int vendor_id)

Returns a iterable subset of the AVPs. This is mainly useful for the new-style foreach statement as in

 for(AVP avp : message.subset(...something...)) {
    //process the AVP
 }
 

Parameters:

code - The AVP code

Returns:

An iterable subset

find

public AVP find(int code)

Finds an AVP with the specified code. Implemented as find(code,0);

find

public AVP find(int code,
                int vendor_id)

Finds an AVP with the specified code/vendor-id. Returns an AVP with the specified code (and vendor-id) if any. If there are no AVPs in this message with the specified code/vendor-id then null is returned. It is unspecified which AVP is returned if there are multiple matches.

Parameters:

code - AVP code

vendor_id - Vendor-ID. Use 0 to specify none.

Returns:

AP with the specified code/vendor-id. Null if not found.