How to select few elements in json using groovy - json

Question

I have following json file,
{
"catalog": {
"book": [
{
"id": "bk101",
"author": "Gambardella, Matthew",
"title": "XML Developer's Guide",
"genre": "Computer",
"price": "44.95",
"publish_date": "2000-10-01",
"description": "An in-depth look at creating applications with XML."
},
{
"-id": "bk102",
"author": "Ralls, Kim",
"title": "Midnight Rain",
"genre": "Fantasy",
"price": "5.95",
"publish_date": "2000-12-16",
"description": "A former architect battles "
}
]
}
}
I want to get only few elements from the above, for eg.
catalog.book[0].title should give result
{
"catalog": {
"book": [
{ "title": "XML Developer's Guide"}
]
}
}
But it will give result only {"title": "XML Developer's Guide"}, the tree is missing.
Please help.

Answer 1

you have to create a function which return the subset of json .subset contain all the field you want
//simple javascript code
function subset_of_json(jsonobj,fieldsYouWant){
//fieldsYouWant is an array ['title'] or ['title' ,'id'] or any field you want
var json ={catalog :{book:[]}};
var bookArr =jsonobj.catalog.book;
for(var i=0;i<bookArr.length;i++){
var obj ={};
for(var k=0;k<fieldsYouWant.length;k++){
obj[fieldsYouWant[k]]=bookArr[i][fieldsYouWant[k]];
}
json.catalog.book.push(obj)
}
return json
}