Question

I need to implement a Routing Table where there are a number of paramters.

For eg, i am stating five attributes in the incoming message below

Customer Txn Group Txn Type Sender Priority  Target UTI       CORP     ONEOFF   ABC    LOW       TRG1 UTI       GOV      ONEOFF   ABC    LOW       TRG2 

What is the best way to represent this data in XML so that it can be queried efficiently.

I want to store this data in XML and using Java i would load this up in memory and when a message comes in i want to identify the target based on the attributes.

Appreciate any inputs.

Thanks, Manglu

Answer 1

If you’re loading it into memory, it doesn’t really matter what form the XML takes – make it the easiest to read or write by hand, I would suggest. When you load it into memory, then you should transform it into an appropriate data structure. (The exact nature of the data structure would depend on the exact nature of the requirements.)

EDIT: This is to counter the arguments made in comments by Dimitre:

I’m not sure whether you thought I was suggesting that people implement their own hashtable – I certainly wasn’t. Just keep a straight hashtable or perhaps a MultiMap for each column which you want to use as a key. Developers know how to use hashtables.

As for the runtime efficiency, which do you think is going to be more efficient:

• You build some XSLT (and bear in mind this is foreign territory, at least relatively speaking, for most developers)
• XSLT engine parses it. This step may be avoidable if you’re using an XSLT library which lets you just parameterise an existing query. Even so, you’ve got some extra work to do.
• XSLT engine hits hashtables (you hope, at least) and returns a node
• You convert the node into a more useful data structure

Or:

• You look up appropriate entries in your hashtable based on the keys you’ve been given, getting straight to a useful data structure

I think I’d trust the second one, personally. Using XSLT here feels like using a screwdriver to bash in a nail…