Call Paginated Spring rest api from another spring project - rest

Question

I build one API which is paginated, its output looks like this:
{
"content": [
{JSON1},
{JSON2},
...
{JSON20}
],
"pageable": {
"sort": {
"sorted": true,
"unsorted": false,
"empty": false
},
"offset": 0,
"pageSize": 20,
"pageNumber": 0,
"unpaged": false,
"paged": true
},
"totalPages": 2,
"totalElements": 32,
"last": false,
"size": 20,
"number": 0,
"sort": {
"sorted": true,
"unsorted": false,
"empty": false
},
"numberOfElements": 20,
"first": true,
"empty": false
}
So for this call, I have two pages and one each page we have 20 JSON entity is coming.
I wanted to call this same endpoint from the rest template.
Before pagination I used to call the same endpoint like this:
MyEntity[] responseEntity;
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.set("Accept", MediaType.APPLICATION_JSON_VALUE);
// request entity is created with request headers
HttpEntity<MyEntity> requestEntity = new HttpEntity<>(requestHeaders);
Map<String, String> params = new HashMap<>();
params.put("feild1", val1);
params.put("feild2", val2);
responseEntity = restTemplate.getForObject(ApiEndpoint,MyEntity[].class,params);
As the endpoint was returning in the format of Array of MyEntity, above code as good enough. Now I have paginated rest endpoint.
How should I call the paginated endpoint and get the Array of MyEntity data again?
So far I have tried calling with: which is not working for me.
UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(ApiEndpoint);
for (Map.Entry<String, String> entry : params.entrySet()) {
builder.queryParam(entry.getKey(), entry.getValue());
}
ResponseEntity<MyEntity[]> response = restTemplate.exchange(builder.toUriString(), HttpMethod.GET, requestEntity, MyEntity[].class);
Let me know if another way you have can be implemented here. Thanks for your help in advance.

Answer 1

What i did is, created the new class RestPageImpl
#JsonIgnoreProperties(ignoreUnknown = true)
public class RestPageImpl<ConfigurationTable> extends PageImpl<ConfigurationTable> {
private static final long serialVersionUID = -1423116752405536063L;
#JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
public RestPageImpl(
#JsonProperty("content") List<ConfigurationTable> content,
#JsonProperty("number") int number, #JsonProperty("size") int size,
#JsonProperty("totalElements") Long totalElements, #JsonProperty("pageable") JsonNode pageable,
#JsonProperty("last") boolean last, #JsonProperty("totalPages") int totalPages,
#JsonProperty("sort") JsonNode sort, #JsonProperty("first") boolean first,
#JsonProperty("numberOfElements") int numberOfElements) {
super(content, PageRequest.of(number, size), totalElements);
}
public RestPageImpl(List<ConfigurationTable> content, Pageable pageable,
long total) {
super(content, pageable, total);
}
public RestPageImpl(List<ConfigurationTable> content) {
super(content);
}
public RestPageImpl() {
super(new ArrayList<>());
}
}
And on the controller side updated my code to:
MyEntity[] responseEntity =null;
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.set("Accept", MediaType.APPLICATION_JSON_VALUE);
// request entity is created with request headers
HttpEntity<MyEntity> requestEntity = new HttpEntity<>(requestHeaders);
Map<String, String> params = new HashMap<>();
params.put("feild1", val1);
params.put("feild2", val2);
UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(ApiEndpoint);
for (Map.Entry<String, String> entry : params.entrySet()) {
builder.queryParam(entry.getKey(), entry.getValue());
}
ParameterizedTypeReference<RestPageImpl<MyEntity>> type = new ParameterizedTypeReference<RestPageImpl<MyEntity>>() {
};
responseEntity = restTemplate.exchange(builder.toUriString(), HttpMethod.GET, requestEntity, type);
And everything works fine now.