如何使用 AsyncTask 从 URL 返回单个 object

Question

I want to try and return a single object within my JSON response. This is the response which I get and I want the app to display just the film name rather than everything. I want it to return just the name eg "Casino" not "film_name": "Casino" .

JSON Response

{
    "films": [
        {
            "film_id": 3139,
            "imdb_id": 112641,
            "film_name": "Casino",
            "release_dates": [
                {
                    "release_date": "1995-11-28",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "18 ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/18.png",
                    "age_advisory": "strong violence"
                }
            ],
            "film_trailer": null,
            "synopsis_long": "Robert DeNiro, Sharon Stone and Joe Pesci star in director Martin Scorsese's riveting look at how blind ambition, white-hot passion and 24-karat greed toppled an empire. Las Vegas 1973 is the setting for this fact-based story about the Mob's multi-million dollar casino operation - where fortunes and lives were made and lost with a roll of the dice.",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "global",
                        "medium": {
                            "film_image": "https://image.movieglu.com/3139/003139h1.jpg",
                            "width": 199,
                            "height": 300
                        }
                    }
                }
            }
        },
        {
            "film_id": 7257,
            "imdb_id": 80455,
            "film_name": "The Blues Brothers",
            "release_dates": [
                {
                    "release_date": "2009-07-24",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "15 ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/15.png",
                    "age_advisory": ""
                }
            ],
            "film_trailer": "https://trailer.movieglu.com/7257_high.mp4",
            "synopsis_long": "Jake and Elwood Blues endeavor to raise $5,000 for their childhood parrish by putting their old band back together uand taking their show on the road. While touring, they manage to wreak havoc on the entire city of Chicago and much of the midwest.",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "UK",
                        "medium": {
                            "film_image": "https://image.movieglu.com/7257/GBR_007257h0.jpg",
                            "width": 200,
                            "height": 300
                        }
                    },
                    "2": {
                        "image_orientation": "portrait",
                        "region": "global",
                        "medium": {
                            "film_image": "https://image.movieglu.com/7257/AUS_007257h0.jpg",
                            "width": 164,
                            "height": 300
                        }
                    }
                }
            }
        },
        {
            "film_id": 12486,
            "imdb_id": 94336,
            "film_name": "Withnail & I",
            "release_dates": [
                {
                    "release_date": "2007-09-07",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "15 ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/15.png",
                    "age_advisory": ""
                }
            ],
            "film_trailer": null,
            "synopsis_long": "",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "UK",
                        "medium": {
                            "film_image": "https://image.movieglu.com/12486/GBR_012486h0.jpg",
                            "width": 200,
                            "height": 300
                        }
                    }
                }
            }
        },
        {
            "film_id": 279925,
            "imdb_id": 7549996,
            "film_name": "Judy",
            "release_dates": [
                {
                    "release_date": "2019-10-04",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "12A ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/12a.png",
                    "age_advisory": "scenes of drug misuse, infrequent strong language"
                }
            ],
            "film_trailer": "https://trailer.movieglu.com/279925_uk_high_V3.mp4",
            "synopsis_long": "Winter 1968 and showbiz legend Judy Garland arrives in Swinging London to perform a five-week sold-out run at The Talk of the Town. It is 30 years since she shot to global stardom in The Wizard of Oz, but if her voice has weakened, its dramatic intensity has only grown. As she prepares for the show, battles with management, charms musicians and reminisces with friends and adoring fans, her wit and warmth shine through. Even her dreams of love seem undimmed as she embarks on a whirlwind romance with Mickey Deans, her soon-to-be fifth husband. Featuring some of her best-known songs, the film celebrates the voice, the capacity for love, and the sheer pizzazz of \"the world's greatest entertainer.\"",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "UK",
                        "medium": {
                            "film_image": "https://image.movieglu.com/279925/GBR_279925h0.jpg",
                            "width": 202,
                            "height": 300
                        }
                    }
                },
                "still": {
                    "1": {
                        "image_orientation": "landscape",
                        "medium": {
                            "film_image": "https://image.movieglu.com/279925/279925h2.jpg",
                            "width": 300,
                            "height": 200
                        }
                    }
                }
            }
        },
        {
            "film_id": 80849,
            "imdb_id": 77631,
            "film_name": "Grease Sing-A-Long",
            "release_dates": [
                {
                    "release_date": "2010-07-13",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "PG ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/pg.png",
                    "age_advisory": ""
                }
            ],
            "film_trailer": null,
            "synopsis_long": "Rydell High's most famous graduating class is going back to school. A newly restored print brings the highest-grossing musical of all time, \"Grease\" (1978), to the big screen as a sing-along. Join Danny and Sandy with your own crew of T-Birds and Pink Ladies for a carnival ride back to those amazing summer nights!",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "global",
                        "medium": {
                            "film_image": "https://image.movieglu.com/80849/080849h1.jpg",
                            "width": 200,
                            "height": 300
                        }
                    }
                },
                "still": {
                    "1": {
                        "image_orientation": "landscape",
                        "medium": {
                            "film_image": "https://image.movieglu.com/80849/080849h2.jpg",
                            "width": 300,
                            "height": 200
                        }
                    }
                }
            }
        },
        {
            "film_id": 281047,
            "imdb_id": 7715070,
            "film_name": "Horrible Histories: The Movie",
            "release_dates": [
                {
                    "release_date": "2019-07-26",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "PG ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/pg.png",
                    "age_advisory": "mild comic violence, injury detail, rude humour, language"
                }
            ],
            "film_trailer": "https://trailer.movieglu.com/281047_uk_high.mp4",
            "synopsis_long": "Friends, Romans, Celts lend us your ears. The all-conquering Romans rule the civilised world and that includes the stain that is Britain. While the young Emperor Nero must battle his scheming mother Agrippina for ultimate power, Celt queen Boudicca gathers an army in Britain to repel the rotten Romans. Mixed up in this battle for liberation are the teenage Atti, a reluctant Roman soldier, and Orla, a young Celt with dreams of becoming a warrior like Boudicca. Will they fall on opposite sides or forge a friendship in the chaos of Celtic-inspired rebellion?",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "UK",
                        "medium": {
                            "film_image": "https://image.movieglu.com/281047/GBR_281047h0.jpg",
                            "width": 200,
                            "height": 300
                        }
                    }
                },
                "still": {
                    "1": {
                        "image_orientation": "landscape",
                        "medium": {
                            "film_image": "https://image.movieglu.com/281047/281047h2.jpg",
                            "width": 300,
                            "height": 200
                        }
                    }
                }
            }
        },
        {
            "film_id": 2129,
            "imdb_id": 45152,
            "film_name": "Singin' in the Rain",
            "release_dates": [
                {
                    "release_date": "2019-10-18",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "U ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/u.png",
                    "age_advisory": "very mild comic violence"
                }
            ],
            "film_trailer": "https://trailer.movieglu.com/2129_high.mp4",
            "synopsis_long": "Gene Kelly, Debbie Reynolds and Donald O'Connor star in Singin' in the Rain, one of the greatest and most successful musicals ever filmed - filled with memorable songs, lavish routines and Kelly's fabulous song-and-dance number performed in the rain.\n\nSet during the advent of \"talkies,\" Don Lockwood  has risen to stardom during Hollywood's silent-movie era - paired with the beautiful, jealous and dumb Lina Lamont. And when Lockwood becomes attracted to young studio singer Kathy Selden, Lamont has her fired.\n\nBut with the introduction of talking pictures, Lockwood finds his career in jeopardy after audiences laugh when they hear Lamont speak in her shrill voice for the first time... until the studio decides to use Selden to dub her voice.",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "UK",
                        "medium": {
                            "film_image": "https://image.movieglu.com/2129/GBR_002129h0.jpg",
                            "width": 200,
                            "height": 300
                        }
                    },
                    "2": {
                        "image_orientation": "portrait",
                        "region": "global",
                        "medium": {
                            "film_image": "https://image.movieglu.com/2129/AUS_002129h0.jpg",
                            "width": 220,
                            "height": 300
                        }
                    }
                },
                "still": {
                    "1": {
                        "image_orientation": "landscape",
                        "medium": {
                            "film_image": "https://image.movieglu.com/2129/002129h2.jpg",
                            "width": 300,
                            "height": 200
                        }
                    }
                }
            }
        },
        {
            "film_id": 6548,
            "imdb_id": 38669,
            "film_name": "The Killers (1946)",
            "release_dates": [
                {
                    "release_date": "1946-09-16",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "PG ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/pg.png",
                    "age_advisory": ""
                }
            ],
            "film_trailer": null,
            "synopsis_long": "",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "UK",
                        "medium": {
                            "film_image": "https://image.movieglu.com/6548/GBR_006548h0.jpg",
                            "width": 200,
                            "height": 300
                        }
                    }
                }
            }
        },
        {
            "film_id": 4705,
            "imdb_id": 96928,
            "film_name": "Bill & Ted's Excellent Adventure",
            "release_dates": [
                {
                    "release_date": "1989-08-25",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "PG ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/pg.png",
                    "age_advisory": "Contains mild language and violence"
                }
            ],
            "film_trailer": null,
            "synopsis_long": "Bill Preston and Ted Logan are two totally excellent dudes facing one most heinous history exam. With the help of Rufus an ultra-cool messenger in a time traveling phone booth, the triumphant two-some bag a bevy of historical heavy weights like the \"Bodacious Philosopher Socrates, \"One Very Excellent Barbarian\" Genghis Khan, the \"Short Dead Dude\" Napoleon and Noah's Wife Joan of Arc to stage the most hysterical high school project ever. History's about to be rewritten by two guys who can't even spell.",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "UK",
                        "medium": {
                            "film_image": "https://image.movieglu.com/4705/GBR_004705h0.jpg",
                            "width": 200,
                            "height": 300
                        }
                    }
                }
            }
        },
        {
            "film_id": 3855,
            "imdb_id": 93191,
            "film_name": "Wings of Desire",
            "release_dates": [
                {
                    "release_date": "1990-10-01",
                    "notes": "GBR"
                }
            ],
            "age_rating": [
                {
                    "rating": "12 ",
                    "age_rating_image": "https://assets.movieglu.com/age_rating_logos/uk/12.png",
                    "age_advisory": "Contains one use of strong language"
                }
            ],
            "film_trailer": null,
            "synopsis_long": "\"Wings of Desire\" is one of cinema's loveliest city symphonies. Bruno Ganz is Damiel, an angel perched atop buildings high over Berlin who can hear the thoughts fears, hopes, dreams of all the people living below. But when he falls in love with a beautiful trapeze artist, he is willing to give up his immortality and come back to earth to be with her. Made not long before the fall of the Berlin wall, this stunning tapestry of sounds and images, shot in black and white and color by the legendary Henri Alekan, is movie poetry. And it forever made the name Wim Wenders synonymous with film art.",
            "images": {
                "poster": {
                    "1": {
                        "image_orientation": "portrait",
                        "region": "UK",
                        "medium": {
                            "film_image": "https://image.movieglu.com/3855/GBR_003855h0.jpg",
                            "width": 200,
                            "height": 300
                        }
                    }
                },
                "still": {
                    "1": {
                        "image_orientation": "landscape",
                        "medium": {
                            "film_image": "https://image.movieglu.com/3855/003855h2.jpg",
                            "width": 300,
                            "height": 200
                        }
                    }
                }
            }
        }
    ],
    "status": {
        "count": 10,
        "state": "OK",
        "method": "filmsNowShowing",
        "message": null,
        "request_method": "GET",
        "version": "WALS_2v200",
        "territory": "UK",
        "device_datetime_sent": "2020-05-17T08:30:17.360Z",
        "device_datetime_used": "2020-05-17 08:30:17"
    }
}

AsyncTaskClass

public class GetFilmsTask extends AsyncTask {
    //String films = "UNDEFINED";
    private TextView textView;
    StringBuilder builder = new StringBuilder();

    public GetFilmsTask(TextView textView) {
        this.textView = textView;
    }

    @Override
    protected String doInBackground(Object[] objects) {
        URL url = null;
        HttpsURLConnection urlConnection = null;
        try{
            url = new URL("https://api-gate2.movieglu.com/filmsNowShowing/?n=10");
            urlConnection = (HttpsURLConnection) url.openConnection();
            urlConnection.setRequestProperty("api-version", "v200");
            urlConnection.setRequestProperty("Authorization", "*****************************");
            urlConnection.setRequestProperty("client", "*******");
            urlConnection.setRequestProperty("x-api-key", "v***********************************");
            urlConnection.setRequestProperty("device-datetime", "2018-09-14T08:30:17.360Z");
            urlConnection.setRequestProperty("territory", "UK");
        }catch(Exception ex){

        }

        try {
            InputStream stream = new BufferedInputStream(urlConnection.getInputStream());
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(stream));
            //here is a temporary string to hold each line that is read from the reader

            String inputLine;
            while ((inputLine = bufferedReader.readLine()) != null) {
                builder.append(inputLine);
                //builder.append("film_name");
            }


            /*JSONObject topLevel = new JSONObject(builder.toString());
            JSONObject filmName = topLevel.getJSONObject("film_name");
            films = filmName.getString("film_name");*/

        }catch(Exception ex){
            System.out.println(ex.toString());
        }
        finally {
            //closes the connection.
            urlConnection.disconnect();
        }

        return null;
    }

    @Override
    protected void onPostExecute(Object o) {
        textView.setText("Current Film: " + builder);
        Log.d("good", String.valueOf(builder));
    }
}

Answer 1

you'll definitely want to spend some time looking at the AsyncTask https://developer.android.com/reference/android/os/AsyncTaskdocumentation to get an understanding how it works. Honestly, most of your time will be spent reading API docs for the rest of your development life - also be aware that AsyncTask is deprecated.

One of the most confusing things is, you're looking up a LIST of films, but only setting ONE title to the text view, so something is up design wise that you want to look into.

But since you have the JSON and you need to get films, you probably want to set something up like this:

// com.example.film.Film
// Create your film class which does the work
public class Film {
    private long id;        // film_id
    private long imdbId;    // imdb_id
    private String title;   // name also where film.getTitle() comes from
    ...
}

You'll need to look at JSON parsing, but your code looks like you've already started to dabble (commented out) so just keep on going with that.

Now you want to create an AsyncTask that gets your film lists

/**
 * The generics you use here can be read about on the AsyncTask documentation page.
 * String - is going to be your String[] args for the request
 * Integer - is going to be what you use to update progress (although you can skip for now)
 * List<Film> - is going to be the response that you get from doInBackground and passed into onPostExecute.
 */
public class GetFilmsAsyncTask extends AsyncTask<String,Integer,List<Film>> {
    @Override
    protected List<Film> doInBackground(String[] objects) { 
        // Use your String[] to build your URL, maybe page size, maybe filter, etc.
        return filmList;  // Parsed from Json
    }

    @Override
    protected void onPostExecute(List<Film> films) {
        // Now do stuff with the film list you got
    }
}

I'm guessing this is closer to what you want, but there are still some missing things: - Instead of TextView you probably want to provide this data to a list view of some kind - You'll need to look into your JSON processing