How to get the total page number for pagination - spring

Question

I try to make my pageable data for weeks everything works but I would like to know the total number of pagination pages here are the data of my mongonDB.
{
"content": [
{
"mame": "iPhone X",
"eategory": "High-Tech",
"productId": "aDPXF7Xq",
"details": {
"vating": "00",
"stocks": "20",
"price": "800000",
"tags": [
{
"tagsl": "Apple",
"tags2": "aull",
"tags3": null
}
],
"brand": "Apple",
"description": "Iphone xX",
"picture": [
{
"picturel": "photol",
"picture2": null,
"picture3": null,
"picture4": null,
"picture5": null
}
],
"thumbnails": [
{
"thumbnaill": "thumbails 1",
"thumbnail2": null,
"thumbnail3": null,
"thumbnail4": null,
"thumbnail5": null
}
]
}
},
{
"mame": "iPhone X",
"eategory": "High-Tech",
"productId": "cjjVqOBk",
"details": {
"rating": "10",
"stocks": "20",
"price": "800000",
"tags": [
{
"tagsl": "Apple",
"tags2": "aull",
"tags3": null
}
],
"brand": "Apple",
"description": "Iphone xX",
"picture": [
{
"picturel": "photol",
"picture2": null,
"picture3": null,
"picture4": null,
"picture5": null
}
],
"thumbnails": [
{
"thumbnaill": "thumbails 1",
"thumbnail2": null,
"thumbnail3": null,
"thumbnail4": null,
"thumbnail5": null
}
]
}
},
{
"mame": "iPhone X",
"eategory": "High-Tech",
"productId": "LhKiRGr6",
"details": {
"vating": "10",
"stocks": "20",
"price": "800000",
"tags": [
{
"tagsl": "Apple",
"tags2": "aull",
"tags3": null
}
],
"brand": "Apple",
"description": "Iphone xX",
"picture": [
{
"picturel": "photol",
"picture2": null,
"picture3": null,
"picture4": null,
"picture5": null
}
],
"thumbnails": [
{
"thumbnaill": "thumbails 1",
"thumbnail2": null,
"thumbnail3": null,
"thumbnail4": null,
"thumbnail5": null
}
]
}
},
{
"mame": "iPhone X",
"eategory": "High-Tech",
"productId": "dgCvi8NJ",
"details": {
"vating": "10",
"stocks": "20",
"price": "800000",
"tags": [
{
"tagsl": "Apple",
"tags2": "aull",
"tags3": null
}
],
"brand": "Apple",
"description": "Iphone xX",
"picture": [
{
"picturel": "photol",
"picture2": null,
"picture3": null,
"picture4": null,
"picture5": null
}
],
"thumbnails": [
{
"thumbnaill": "thumbails 1",
"thumbnail2": null,
"thumbnail3": null,
"thumbnail4": null,
"thumbnail5": null
}
]
}
}
],
"pageable": {
"sort": {
"sorted": false,
"unsorted": true,
"empty": true
},
"offset": 0,
"pageNumber": 0,
"pageSize": 20,
"paged": true,
"unpaged": false
},
"totalPages": 1,
"totalElements": 4,
"last": true,
"size": 20,
"sort": {
"sorted": false,
"unsorted": true,
"empty": true
},
"number": 0,
"numberOfElements": 4,
"first": true,
"empty": false
}
Now here is the data paging code
#GetMapping("/engine/search")
public PageImpl<Products> engineSearch(#RequestParam("p") String query, #RequestParam(value = "page", defaultValue = "0") int page, Pageable pageable) {
Criteria criteria = new Criteria();
final Aggregation aggregation = Aggregation.newAggregation(
Aggregation.match( criteria.orOperator(
Criteria.where( "name" ).regex( query, "i" ),
Criteria.where( "details.brand" ).regex( query, "i" ),
Criteria.where( "details.tags.tags1" ).regex( query, "i" ),
Criteria.where( "details.tags.tags2" ).regex( query, "i" ),
Criteria.where( "details.tags.tags3" ).regex( query, "i" )
)),
Aggregation.skip(page * 4),
Aggregation.limit(4)
);
List<Products> filter = mongoTemplate.aggregate(aggregation, "Product", Products.class).getMappedResults();
return new PageImpl<Products>(filter, pageable, filter.size());
}

Answer 1

Mongodb 3.4 has introduced $facet aggregation which processes multiple aggregation pipelines within a single stage on the same set of input documents.
Using $facet and $group you can find documents with $limit and can get total count.
You can use below aggregation in mongodb 3.6
db.collection.aggregate([
{ "$facet": {
"totalData": [
{ "$match": { }},
{ "$skip": 10 },
{ "$limit": 10 }
],
"totalCount": [
{ "$count": "count" }
]
}}
])