How to deserialize Json Springboot webservice

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How to deserialize Json Springboot webservice

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#2 by (0 votes)

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I'm trying to consume the themoviedb webservice and am encountering the following error.

----------------------- POJO ----------------------- - package com.wsemovie.model;

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

@JsonIgnoreProperties(ignoreUnknown = true)
public class Movie {

    public String adult;        
    public String budget;            
    public String  original_language;
    public String  original_title;
    public String  overview;    
    public String  title;


    public Movie() {
        super();
    }
    public String getAdult() {
        return adult;
    }
    public void setAdult(String adult) {
        this.adult = adult;
    }
    public String getBudget() {
        return budget;
    }
    public void setBudget(String budget) {
        this.budget = budget;
    }
    public String getOriginal_language() {
        return original_language;
    }
    public void setOriginal_language(String original_language) {
        this.original_language = original_language;
    }
    public String getOriginal_title() {
        return original_title;
    }
    public void setOriginal_title(String original_title) {
        this.original_title = original_title;
    }
    public String getOverview() {
        return overview;
    }
    public void setOverview(String overview) {
        this.overview = overview;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
}

-------------- Controller ---------------------

@Controller
public class MovieController {   
    @GetMapping("/") 
    @ResponseBody
    public String movies(Model model ) {        
        RestTemplate restTemplate = new RestTemplate();
        ResponseEntity<List<Movie>> resposne = 
                restTemplate.exchange(
                "https://api.themoviedb.org/3/movie/55?api_key=8a39fa19e513b70d41402ac67813ae35",            
                HttpMethod.GET,
                null,
                new ParameterizedTypeReference<List<Movie>>() { }
                );
        List<Movie> lista = resposne.getBody();

        model.addAttribute("lista", lista);
        return "movie"; //Invocando o template thymeleaf
    }   
}

---------------------- JSON ------------------------ -----------

{ "adult": false, "backdrop_path": "/AuXC0SsPZaAfddtSMnxSnbEeEjR.jpg", "belongs_to_collection": null, "budget": 2000000, "genres": [ { "id": 18, "name": "Drama" }, { "id": 53, "name": "Thriller" } ], "homepage": null, "id": 55, "imdb_id": "tt0245712", "original_language": "is", "original_title": "Amores perros", "overview": "Three different people in Mexico City are catapulted into dramatic and unforeseen circumstances in the wake of a terrible car crash: a young punk stumbles into the sinister underground world of dog fighting; ; and an ex-radical turned hit man rescues a gunshot Rotweiler. ", "popularity": 5,686, "poster_path": "/8gEXmIzw1tDnBfOaCFPimkNIkmm.jpg", "production_companies": [ { "id": 5084, "logo_path": null, "name": "Altavista Films", "origin_country": "" }, { "id": 11230, "logo_path": null, "name": "Zeta Film", "origin_country": "" } ], "production_countries": [ { "iso_3166_1": "MX", "name": "Mexico" } ], "release_date": "2000-06-16", "revenue": 20908467, "runtime": 154, "spoken_languages": [ { "iso_639_1": "is", "name": "Spanish" } ], "status": "Released", "tagline": "Love. Betrayal. Death.", "title": "Amores Perros", "video": false, "vote_average": 7.7, "vote_count": 855 }

There was an unexpected error (type = Internal Server Error, status = 500). Error while extracting response for type [java.util.List] and content type [application / json; charset = utf-8]; nested exception is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token at [Source: (PushbackInputStream); line: 1, column: 1] org.springframework.web.client.RestClientException: Error while extracting response for type [java.util.List] and content type [application / json; charset = utf-8]; nested exception is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token at [Source: (PushbackInputStream); line: 1, column: 1]

java json spring-boot

asked by anonymous 20.12.2018 / 01:04

2 answers

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score 0 · Answer 1

By all indications, the API call would return some attributes that would make up your Movie object, not a list of them. You could try the following approach: deserialize JSON by populating a Movie object and then adding the object to the list with the Google gson library:

Dependency:

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.6.2</version>
</dependency>

Implementation:

Gson gson = new Gson(); //instancie o obj Gson
String jsonInString = resposne.getBody(); //se não for uma String, o que acho difícil, converta
Movie filme = new Movie();
filme = gson.fromJson(jsonInString, Movie.class);
lista.add(filme);

For more details, take a look:

score 0 · Answer 2

From what I saw you are deserializing a List<Cotacao> and not a Movie as you included in the question, probably the JSON return is not a list and you are trying to deserialize to list.

Edit

By checking your JSON you are only receiving one instance of Movie , and you are parsing directly to List<Movie> . Swap code to only serialize Movie instead of list