Hi, has any one had to implement the parsing of the JQGrid multisearch filter json in a grails controller before?

The JSON comes through in the format below

{
"groupOp":"AND",
"rules":[
{
"field":"customernumber",
"op":"lt",
"data":"200"
}
,
{
"field":"country",
"op":"eq",
"data":"USA"
}
]
}

And I was wondering, before I tackle it myself, if anybody else had some example code or library that would be worth looking at. I have looked at the JQGrid plugin for grails but I could not see that it covered the advanced multisearch, just the standard tool bar search.

Thanks in advance