How can I get data in json array by ID

I have a problem, may you help me! I have a json array:

"category" : [
{
    id: 1,
    product: [{id : product_1, type : ball}] 
},
{
    id : 2,
    product :[{id : product_2, type : pen}]
}
]

My problem is: if i have a link such as: http://test/category/1 then , How can I do to get product information by category with id = 1 ? Thanks for any suggestion :)