Serializing using Rest Assured response.jsonPath().getObject() returns null

Question

I have an API returning JSON which looks like this

{"listings":[
 {
    "albumId": 1,
    "id": 1,
    "title": "accusamus beatae ad facilis cum similique qui sunt",
    "url": "https://via.placeholder.com/600/92c952",
    "thumbnailUrl": "https://via.placeholder.com/150/92c952"
  },
  {
    "albumId": 1,
    "id": 2,
    "title": "reprehenderit est deserunt velit ipsam",
    "url": "https://via.placeholder.com/600/771796",
    "thumbnailUrl": "https://via.placeholder.com/150/771796"
  },
  {
    "albumId": 1,
    "id": 3,
    "title": "officia porro iure quia iusto qui ipsa ut modi",
    "url": "https://via.placeholder.com/600/24f355",
    "thumbnailUrl": "https://via.placeholder.com/150/24f355"
  },
  {
    "albumId": 1,
    "id": 4,
    "title": "culpa odio esse rerum omnis laboriosam voluptate repudiandae",
    "url": "https://via.placeholder.com/600/d32776",
    "thumbnailUrl": "https://via.placeholder.com/150/d32776"
  },
  {
    "albumId": 1,
    "id": 5,
    "title": "natus nisi omnis corporis facere molestiae rerum in",
    "url": "https://via.placeholder.com/600/f66b97",
    "thumbnailUrl": "https://via.placeholder.com/150/f66b97"
  },
]}

I want to serialize that JSON to my MyObject class. I just need 2 variables, so I will just ignore the others.

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

@JsonIgnoreProperties(ignoreUnknown=true)
public class MyObject {

    private String title;
    private String url;

    // Getters and Setters here
}

My test runner looks like this

public class MyTest {

  @Test
  public void runTest() {

    // Usual Rest-Assured GET request here

    Response response = request
      .request(Method.GET);


    List < MyObject > objects = Arrays.asList(response.jsonPath().getObject("listings", MyObject[].class));

    String testOneTitle = response.jsonPath().get("listings[0].title");
    System.out.println("testOneTitle " + testOneTitle); // OK - Returns String of the title

    System.out.println("Size " + objects.size()); // OK -Returns the size of the List

    for (int z = 0; z < 3; z++) {
      System.out.println("Title " + objects.get(z).getTitle()); // NOK - This returns null 
    }
  }
}

Title null
Title null
Title null

I don't know why it returns null.

I suspect this method doesn't serialize the JSON properly?

List < MyObject > objects = Arrays.asList(response.jsonPath().getObject("listings", MyObject[].class));

Any idea why?

Learning from the discussion here , I am guessing Rest-Assured uses 3rd party library to serialize JSON ? Not sure, but I follow the suggestion on that link by adding dependency

// https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind
implementation group: 'com.fasterxml.jackson.core', name: 'jackson-databind', version: '2.12.3'

Answer 1

I didn't really go through the question in detail as I understood the context, It seems like the issue is with the POJO. Here's something I tried in my local machine and I am able to get the expected

@JsonIgnoreProperties(ignoreUnknown = true)
public static class Listing {

    @JsonProperty("listings")
    public List<Listing> listings = null;
    @JsonProperty("title")
    public String title;
    @JsonProperty("url")
    public String url;
    
    // Getters and Setters here

}

public static void main(String[] args) {

    List<Listing> res = RestAssured.given().when().get("http://localhost:8080/stack").then().extract()
            .response().as(Listing.class).getListings();

    for (int z = 0; z < 5; z++) {
        System.out.println("Title " + res.get(z).getTitle());
    }

}