Thread: Need code to get count from huge json file

The json file i'm using is around 4GB. Need java code to get no. of entries from json file.
The "id" must be present multiple times in this huge file, so need to get distinct count.

The file looks like,
{"$xmlns":{"mm":"MetadataManagement","abm":"Title" },"startIndex":1,"itemsPerPage":500,"entryCount":2 08,"entries":[
{"id":"4643245807014,"updated":1373162401000,"titl e":"Life is Elsewhere","added":1351040528000},
{"id":"4643245807015,"updated":1373162401001,"titl e":"Titani","added":1851040528000},
{"id":"4643245807015,"updated":1473162401001,"titl e":"Titanic","added":1851040528000}
]}

The code i used works for a small file but for huge size file it throws out of memory error.
I'm a beginner in java, please help me.

JSONObject jsonObject = (JSONObject) parser.parse(new FileReader("C:\\Kishore\\2013-09-29.17_30_00.full.json"));
JSONArray jsonMainArr = (JSONArray) jsonObject.get("entries");

int count = jsonMainArr.size();
System.out.println("No. of elements = " + count);