Spring RestTemplate with paginated API

Question

Our REST APIs are returning results in Pages. Here is an example of one Controller

@RequestMapping(value = "/search", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE + ";charset=UTF-8") @ResponseStatus(HttpStatus.OK) public Page<MyObject> findAll(Pageable pageable) {   ... } 

Is there an easy way to consume that API with RestTemplate?

if we do

ParameterizedTypeReference<Page<MyObject>> responseType = new ParameterizedTypeReference<Page<MyObject>>() { };  ResponseEntity<Page<MyObject>> result = restTemplate.exchange(url, HttpMethod.GET, null/*httpEntity*/, responseType);  List<MyObject> searchResult = result.getBody().getContent(); 

it throws an exception

org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not construct instance of org.springframework.data.domain.Page,  problem: abstract types either need to be mapped to concrete types, have custom deserializer, or be instantiated with additional type information at [Source: java.io.PushbackInputStream@3be1e1f2; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of org.springframework.data.domain.Page, problem: abstract types either need to be mapped to concrete types, have custom deserializer, or be instantiated with additional type information 

Thank you in advance

Answer 1

When migrating from Spring Boot 1.x to 2.0, changed the code reading the Rest API response as

import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.fasterxml.jackson.databind.JsonNode;  import org.springframework.data.domain.PageImpl; import org.springframework.data.domain.PageRequest; import org.springframework.data.domain.Pageable;  import java.util.ArrayList; import java.util.List;  public class RestPageImpl<T> extends PageImpl<T>{      @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)     public RestPageImpl(@JsonProperty("content") List<T> 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<T> content, Pageable pageable, long total) {         super(content, pageable, total);     }      public RestPageImpl(List<T> content) {         super(content);     }      public RestPageImpl() {         super(new ArrayList<>());     } }