FATAL EXCEPTION: ModernAsyncTask #1 An error occured while executing doInBackground()

[Jared Snyder]

I've never seen this error before and don't even know where to start. This Activity is supposed to fetch results from Google Places and is part of a search functionality that ties in with the search view widget. Someone set me in the right direction. Thanks!



PlaceProvider.java:

package com. ...; //Removed for forum
 
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.List;
 
import org.json.JSONException;
import org.json.JSONObject;
 
import android.app.SearchManager;
import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.net.Uri;
import android.util.Log;
 
public class PlaceProvider extends ContentProvider {
 
    public static final String AUTHORITY = "com.....PlaceProvider"; //Removed for forum
 
    public static final Uri SEARCH_URI = Uri.parse("content://"+AUTHORITY+"/search");
 
    public static final Uri DETAILS_URI = Uri.parse("content://"+AUTHORITY+"/details");
 
    private static final int SEARCH = 1;
    private static final int SUGGESTIONS = 2;
    private static final int DETAILS = 3;
 
    // Obtain browser key from https://code.google.com/apis/console
    String mKey = "key=MY_API_KEY"; //Removed for forum
 
    // Defines a set of URIs allowed with this content provider
    private static final UriMatcher mUriMatcher = buildUriMatcher();
 
    private static UriMatcher buildUriMatcher() {
 
        UriMatcher uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
 
        // URI for "Go" button
        uriMatcher.addURI(AUTHORITY, "search", SEARCH );
 
        // URI for suggestions in Search Dialog
        uriMatcher.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY,SUGGESTIONS);
 
        // URI for Details
        uriMatcher.addURI(AUTHORITY, "details",DETAILS);
 
        return uriMatcher;
    }
 
    @Override
    public Cursor query(Uri uri, String[] projection, String selection,
        String[] selectionArgs, String sortOrder) {
        Cursor c = null;
 
        PlaceJSONParser parser = new PlaceJSONParser();
        PlaceDetailsJSONParser detailsParser = new PlaceDetailsJSONParser();
 
        String jsonString = "";
        String jsonPlaceDetails = "";
 
        List<HashMap<String, String>> list = null;
        List<HashMap<String, String>> detailsList = null;
 
        MatrixCursor mCursor = null;
 
        switch(mUriMatcher.match(uri)){
        case SEARCH:
            // Defining a cursor object with columns description, lat and lng
            mCursor = new MatrixCursor(new String[] { "description","lat","lng" });
 
            // Create a parser object to parse places in JSON format
            parser = new PlaceJSONParser();
 
            // Create a parser object to parse place details in JSON format
            detailsParser = new PlaceDetailsJSONParser();
 
            // Get Places from Google Places API
            jsonString = getPlaces(selectionArgs);
            try {
                // Parse the places ( JSON => List )
                list = parser.parse(new JSONObject(jsonString));
 
                // Finding latitude and longitude for each places using Google Places Details API
                for(int i=0;i<list.size();i++){
                    HashMap<String, String> hMap = (HashMap<String, String>) list.get(i);
 
                    detailsParser =new PlaceDetailsJSONParser();
 
                    // Get Place details
                    jsonPlaceDetails = getPlaceDetails(hMap.get("reference"));
 
                    // Parse the details ( JSON => List )
                    detailsList = detailsParser.parse(new JSONObject(jsonPlaceDetails));
 
                    // Creating cursor object with places
                    for(int j=0;j<detailsList.size();j++){
                        HashMap<String, String> hMapDetails = detailsList.get(j);
 
                        // Adding place details to cursor
                        mCursor.addRow(new String[]{ hMap.get("description") , hMapDetails.get("lat") , hMapDetails.get("lng") });
                    }
 
                }
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            c = mCursor;
            break;
 
        case SUGGESTIONS :
 
            // Defining a cursor object with columns id, SUGGEST_COLUMN_TEXT_1, SUGGEST_COLUMN_INTENT_EXTRA_DATA
            mCursor = new MatrixCursor(new String[] { "_id", SearchManager.SUGGEST_COLUMN_TEXT_1, SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA } );
 
            // Creating a parser object to parse places in JSON format
            parser = new PlaceJSONParser();
 
            // Get Places from Google Places API
            jsonString = getPlaces(selectionArgs);
 
            try {
                // Parse the places ( JSON => List )
                list = parser.parse(new JSONObject(jsonString));
 
                // Creating cursor object with places
                for(int i=0;i<list.size();i++){
                    HashMap<String, String> hMap = (HashMap<String, String>) list.get(i);
 
                    // Adding place details to cursor
                    mCursor.addRow(new String[] { Integer.toString(i), hMap.get("description"), hMap.get("reference") });
                }
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            c = mCursor;
            break;
 
        case DETAILS :
            // Defining a cursor object with columns description, lat and lng
            mCursor = new MatrixCursor(new String[] { "description","lat","lng" });
 
            detailsParser = new PlaceDetailsJSONParser();
            jsonPlaceDetails = getPlaceDetails(selectionArgs[0]);
            try {
                detailsList = detailsParser.parse(new JSONObject(jsonPlaceDetails));
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
 
            for(int j=0;j<detailsList.size();j++){
                HashMap<String, String> hMapDetails = detailsList.get(j);
                mCursor.addRow(new String[]{ hMapDetails.get("formatted_address") , hMapDetails.get("lat") , hMapDetails.get("lng") });
            }
            c = mCursor;
            break;
        }
        return c;
    }
 
    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        // TODO Auto-generated method stub
        return 0;
    }
 
    @Override
    public String getType(Uri uri) {
        // TODO Auto-generated method stub
        return null;
    }
 
    @Override
    public Uri insert(Uri uri, ContentValues values) {
        // TODO Auto-generated method stub
        return null;
    }
 
    @Override
    public boolean onCreate() {
        // TODO Auto-generated method stub
        return false;
    }
 
    @Override
    public int update(Uri uri, ContentValues values, String selection,
        String[] selectionArgs) {
        // TODO Auto-generated method stub
        return 0;
    }
 
    /** A method to download JSON data from url */
    private String downloadUrl(String strUrl) throws IOException{
        String data = "";
        InputStream iStream = null;
        HttpURLConnection urlConnection = null;
        try{
            URL url = new URL(strUrl);
 
            // Creating an http connection to communicate with url
            urlConnection = (HttpURLConnection) url.openConnection();
 
            // Connecting to url
            urlConnection.connect();
 
            // Reading data from url
            iStream = urlConnection.getInputStream();
 
            BufferedReader br = new BufferedReader(new InputStreamReader(iStream));
 
            StringBuffer sb = new StringBuffer();
 
            String line = "";
            while( ( line = br.readLine()) != null){
                sb.append(line);
            }
 
            data = sb.toString();
 
            br.close();
 
        }catch(Exception e){
           Log.d("Exception while downloading url", e.toString());
        }finally{
            iStream.close();
            urlConnection.disconnect();
        }
        return data;
    }
 
    private String getPlaceDetailsUrl(String ref){
 
        // reference of place
        String reference = "reference="+ref;
 
        // Sensor enabled
        String sensor = "sensor=false";
 
        // Building the parameters to the web service
        String parameters = reference+"&"+sensor+"&"+mKey;
 
        // Output format
        String output = "json";
 
        // Building the url to the web service
        String url = "https://maps.googleapis.com/maps/api/place/details/"+output+"?"+parameters;
 
        return url;
    }
 
    private String getPlacesUrl(String qry){
 
        try {
            qry = "input=" + URLEncoder.encode(qry, "utf-8");
        } catch (UnsupportedEncodingException e1) {
            e1.printStackTrace();
        }
 
        // Sensor enabled
        String sensor = "sensor=false";
 
        // place type to be searched
        String types = "types=geocode";
 
        // Building the parameters to the web service
        String parameters = qry+"&"+types+"&"+sensor+"&"+mKey;
 
        // Output format
        String output = "json";
        // Building the url to the web service
        String url = "https://maps.googleapis.com/maps/api/place/autocomplete/"+output+"?"+parameters;
        return url;
    }
 
    private String getPlaces(String[] params){
        // For storing data from web service
        String data = "";
        String url = getPlacesUrl(params[0]);
        try{
            // Fetching the data from web service in background
            data = downloadUrl(url);
        }catch(Exception e){
            Log.d("Background Task",e.toString());
        }
        return data;
    }
 
    private String getPlaceDetails(String reference){
        String data = "";
        String url = getPlaceDetailsUrl(reference);
        try {
            data = downloadUrl(url);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return data;
    }
}

Details from logcat:

03-09 19:05:40.521: E/AndroidRuntime(6976): FATAL EXCEPTION: ModernAsyncTask #1
03-09 19:05:40.521: E/AndroidRuntime(6976): java.lang.RuntimeException: An error occured while executing doInBackground()
03-09 19:05:40.521: E/AndroidRuntime(6976): at android.support.v4.content.ModernAsyncTask$3.done(ModernAsyncTask.java:137)
03-09 19:05:40.521: E/AndroidRuntime(6976): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
03-09 19:05:40.521: E/AndroidRuntime(6976): at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
03-09 19:05:40.521: E/AndroidRuntime(6976): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
03-09 19:05:40.521: E/AndroidRuntime(6976): at java.util.concurrent.FutureTask.run(FutureTask.java:138)
03-09 19:05:40.521: E/AndroidRuntime(6976): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
03-09 19:05:40.521: E/AndroidRuntime(6976): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
03-09 19:05:40.521: E/AndroidRuntime(6976): at java.lang.Thread.run(Thread.java:1019)
03-09 19:05:40.521: E/AndroidRuntime(6976): Caused by: java.lang.NullPointerException
03-09 19:05:40.521: E/AndroidRuntime(6976): at java.net.URLEncoder.encode(URLEncoder.java:92)
03-09 19:05:40.521: E/AndroidRuntime(6976): at com.....PlaceProvider.getPlacesUrl(PlaceProvider.java:266)
03-09 19:05:40.521: E/AndroidRuntime(6976): at com.....PlaceProvider.getPlaces(PlaceProvider.java:290)
03-09 19:05:40.521: E/AndroidRuntime(6976): at com.....PlaceProvider.query(PlaceProvider.java:88)
03-09 19:05:40.521: E/AndroidRuntime(6976): at android.content.ContentProvider$Transport.query(ContentProvider.java:187)
03-09 19:05:40.521: E/AndroidRuntime(6976): at android.content.ContentResolver.query(ContentResolver.java:262)
03-09 19:05:40.521: E/AndroidRuntime(6976): at android.support.v4.content.CursorLoader.loadInBackground(CursorLoader.java:49)
03-09 19:05:40.521: E/AndroidRuntime(6976): at android.support.v4.content.CursorLoader.loadInBackground(CursorLoader.java:35)
03-09 19:05:40.521: E/AndroidRuntime(6976): at android.support.v4.content.AsyncTaskLoader.onLoadInBackground(AsyncTaskLoader.java:242)
03-09 19:05:40.521: E/AndroidRuntime(6976): at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:51)
03-09 19:05:40.521: E/AndroidRuntime(6976): at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:40)
03-09 19:05:40.521: E/AndroidRuntime(6976): at android.support.v4.content.ModernAsyncTask$2.call(ModernAsyncTask.java:123)
03-09 19:05:40.521: E/AndroidRuntime(6976): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
03-09 19:05:40.521: E/AndroidRuntime(6976): ... 4 more

[Jared Snyder]

So, apparently the issue was related to the "qry" not being appropriately checked for null before being passed to the encoder.

This fixed it:

try {

    if (qry != null) {

        qry = "input=" + URLEncoder.encode(qry, "utf-8"); //This is line 266

    }

} catch (UnsupportedEncodingException e1) {
    e1.printStackTrace();
}