Delphi ODAC: Disecting JMS messages from Oracle AQ - delphi

Question

I'm trying to evaluate ODAC for using Oracle AQ.
The request queue contains JMS objects like these (but without linebreaks and other whitespace):
SYS.AQ$_JMS_BYTES_MESSAGE(
SYS.AQ$_JMS_HEADER(
'null','null','null','null','null','null',
SYS.AQ$_JMS_USERPROPARRAY(
SYS.AQ$_JMS_USERPROPERTY('Key1',100,'Value1','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key2',100,'Value2','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key3',100,'Value3','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key4',100,'Value4','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key5',100,'Value5','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key6',100,'Value6','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key7',100,'Value7','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key8',100,'Value8','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key9',100,'Value9','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key10',100,'Value10.0','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key11',100,'Value11','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key12',100,'Value12','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key13',100,'Value13','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key14',100,'Value14','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key15',100,'Value15','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key16',100,'Value16','null',27),
SYS.AQ$_JMS_USERPROPERTY('Key17',100,'Value17','null',27)
)
),
4168,'null','oracle.sql.BLOB#959acc'
)
I can receive the underlying object (a string Payload comes back as an empty string, but a TOraObject PayLoad contains data).
I'm trying to disscect the TOraObject PayLoad, and am looking for a table that converts the DataType values into the correct AttrXxxx[Name] property calls.
OraType.AttributeCount:4
OraType.Name:"SYS"."AQ$_JMS_BYTES_MESSAGE"
OraType.DataType:15
Attribute[0].Name:HEADER
Attribute[0].DataType:15
OraType.AttributeCount:7
OraType.Name:"SYS"."AQ$_JMS_HEADER"
OraType.DataType:15
Attribute[0].Name:REPLYTO
Attribute[0].DataType:15
OraType.AttributeCount:3
OraType.Name:"SYS"."AQ$_AGENT"
OraType.DataType:15
Attribute[0].Name:NAME
Attribute[0].DataType:1
Attribute[1].Name:ADDRESS
Attribute[1].DataType:1
Attribute[2].Name:PROTOCOL
Attribute[2].DataType:5
Attribute[1].Name:TYPE
Attribute[1].DataType:1
Attribute[2].Name:USERID
Attribute[2].DataType:1
Attribute[3].Name:APPID
Attribute[3].DataType:1
Attribute[4].Name:GROUPID
Attribute[4].DataType:1
Attribute[5].Name:GROUPSEQ
Attribute[5].DataType:5
Attribute[6].Name:PROPERTIES
Attribute[6].DataType:17
OraType.AttributeCount:1
OraType.Name:"SYS"."AQ$_JMS_USERPROPARRAY"
OraType.DataType:17
Attribute[0].Name:ELEMENT
Attribute[0].DataType:15
OraType.AttributeCount:5
OraType.Name:"SYS"."AQ$_JMS_USERPROPERTY"
OraType.DataType:15
Attribute[0].Name:NAME
Attribute[0].DataType:1
Attribute[1].Name:TYPE
Attribute[1].DataType:5
Attribute[2].Name:STR_VALUE
Attribute[2].DataType:1
Attribute[3].Name:NUM_VALUE
Attribute[3].DataType:5
Attribute[4].Name:JAVA_TYPE
Attribute[4].DataType:5
Attribute[1].Name:BYTES_LEN
Attribute[1].DataType:5
Attribute[2].Name:BYTES_RAW
Attribute[2].DataType:1
Attribute[3].Name:BYTES_LOB
Attribute[3].DataType:102
By trial and error, I have come so far:
case DataType of
102:
LOB := ObjectPayLoad.AttrAsLob[Name];
15:
AttributeOraObject := ObjectPayLoad.AttrAsObject[Name];
17:
AttributeOraArray := ObjectPayLoad.AttrAsArray[Name];
else
begin
PayLoadAttributeAsString := ObjectPayLoad. AttrAsString[Name];
Logger.Log(' "%s"', [PayLoadAttributeAsString]);
end;
end;
A more complete list is welcome :-)
After this, I will need to research the other way around: generating the right TOraObject that has a JMS content in it.
Tips for that are also welcome.
--jeroen

Answer 1

Edit:
ODAC has multiple units defining constants.
The constant dtOraBlob with value 102 is in the OraClasses unit; constants defining DataType values start with the prefix dt, regardless of the unit that defines them.
Original:
I have found a few of these constants in the MemData unit:
case DataType of
102:
LOB := OraObject.AttrAsLob[Name];
MemData.dtObject: // 15
begin
AttributeOraObject := OraObject.AttrAsObject[Name];
LogOraObject(AttributeOraObject, Level+1);
end;
MemData.dtArray: // 17
begin
AttributeOraArray := OraObject.AttrAsArray[Name];
LogOraArray(AttributeOraArray, Level);
end;
MemData.dtFloat: // 5
begin
AttributeFloat := OraObject.AttrAsFloat[Name];
Logger.Log(Prefix+'"%g"', [AttributeFloat]);
end;
MemData.dtString: // 1
begin
PayLoadAttributeAsString := OraObject.AttrAsString[Name];
Logger.Log(Prefix+'"%s"', [PayLoadAttributeAsString]);
end;
else
begin
PayLoadAttributeAsString := OraObject.AttrAsString[Name];
Logger.Log(Prefix+'"%s"', [PayLoadAttributeAsString]);
end;
end;
I can't find the 102 constant though, but I'm pretty sure it is for a LOB field.
Anyone who can confirm that?
--jeroen