Question

我正在尝试从API提取数据。执行代码时，出现以下错误：

E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.example.smitsanghvi.moviedb, PID: 9844
                  java.lang.IndexOutOfBoundsException: Invalid index 7, size is 0
                      at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
                      at java.util.ArrayList.get(ArrayList.java:308)
                      at com.example.smitsanghvi.moviedb.MainActivity$CheckConnectionStatus.onPostExecute(MainActivity.java:104)
                      at com.example.smitsanghvi.moviedb.MainActivity$CheckConnectionStatus.onPostExecute(MainActivity.java:44)
                      at android.os.AsyncTask.finish(AsyncTask.java:651)
                      at android.os.AsyncTask.-wrap1(AsyncTask.java)
                      at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:148)
                      at android.app.ActivityThread.main(ActivityThread.java:5417)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Application terminated.

MainActivity.java

它连接到API并尝试获取数据。

下面的代码段。

public class MainActivity extends AppCompatActivity {  


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);    
    new CheckConnectionStatus().execute("https://api.themoviedb.org/3/tv/popular?api_key=(IamNotProvidingInQuestion)&language=en-US&page=1");
}

    //created an asynchronous task
class CheckConnectionStatus extends AsyncTask<String, Void, String> {

protected void onPreExecute(){
    super.onPreExecute();

}
    @Override
    protected String doInBackground(String... params) {
        URL url = null;
        try {
            url = new URL(params[0]);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
        try {
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();


            InputStream inputStream=urlConnection.getInputStream();
            BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(inputStream));

            String s=bufferedReader.readLine();
            bufferedReader.close();
            return s;

        } catch (IOException e) {
            Log.e("Error:", e.getMessage(), e);
        }
        return null;

    }

    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        //created json object to read and parse json

        JSONObject jsonObject=null;
        try {
            jsonObject=new JSONObject(s);
            //creating an arraylist for the tv season info
            ArrayList<SeasonInfo>newlist=new ArrayList<>();


            //reading objects from production companies as its an array
            JSONArray jsonArray=jsonObject.getJSONArray("results");
            //iterating to get the id from the company name
            for(int i=0;i<jsonArray.length();i++)
            {

                JSONObject object=jsonArray.getJSONObject(i);
                SeasonInfo seasonInfo=new SeasonInfo();
                seasonInfo.setOriginal_name(object.getString("original_name"));
                seasonInfo.setOverview(object.getString("overview"));
                seasonInfo.setPoster_path(object.getString("poster_path"));
                seasonInfo.setOriginal_language(object.getString("original_language"));
                seasonInfo.setFirst_air_date(object.getString("first_air_date"));


            }
            Log.i("List:",newlist.get(0).getOverview());

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

}

}

SeasonInfo.java

保留JSON数据。

下面的代码段。

public class SeasonInfo {

public  String original_name;
public String overview;
public  String poster_path;
public String original_language;
public String first_air_date;

public String getPoster_path() {
    return poster_path;
}

public void setPoster_path(String poster_path) {
    this.poster_path = poster_path;
}



public String getOriginal_name() {
    return original_name;
}

public void setOriginal_name(String original_name) {
    this.original_name = original_name;
}

public String getOverview() {
    return overview;
}

public void setOverview(String overview) {
    this.overview = overview;
}

public String getOriginal_language() {
    return original_language;
}

public void setOriginal_language(String original_language) {
    this.original_language = original_language;
}

public String getFirst_air_date() {
    return first_air_date;
}

public void setFirst_air_date(String first_air_date) {
    this.first_air_date = first_air_date;
}

}

这是我正在我的应用程序中使用的来自网站的JSON数据。我在此处附加的JSON数据并不完整，只是第一部分，以便您可以更好地理解。

 [{
"page": 1,
"total_results": 20024,
"total_pages": 1002,
"results": [
{
"original_name": "The Big Bang Theory",
"genre_ids": [],
"name": "The Big Bang Theory",
"popularity": 294.657,
"origin_country": [],
"vote_count": 3133,
"first_air_date": "2007-09-24",
"backdrop_path": "/nGsNruW3W27V6r4gkyc3iiEGsKR.jpg",
"original_language": "en",
"id": 1418,
"vote_average": 6.8,
"overview": "The Big Bang Theory is centered on five characters living in Pasadena, California: roommates Leonard Hofstadter and Sheldon Cooper; Penny, a waitress and aspiring actress who lives across the hall; and Leonard and Sheldon's equally geeky and socially awkward friends and co-workers, mechanical engineer Howard Wolowitz and astrophysicist Raj Koothrappali. The geekiness and intellect of the four guys is contrasted for comic effect with Penny's social skills and common sense.",
"poster_path": "/ooBGRQBdbGzBxAVfExiO8r7kloA.jpg"
}]

Answer 1

尝试对这一行进行注释：

Log.i("List:",newlist.get(0).getOverview());

因为您从未向newlist数组添加任何值，而您正试图获得一些值。

Answer 2

您是否忘记在循环中添加newlist.add(seasonInfo);？
否则，此循环将毫无意义，并且循环后的日志将引发异常。

Android致命异常错误

2 个答案: