While inserting to Android SQLite Database I want to skip the values that user did not fill.
But I am getting null pointer exception.
In my DBHelper class I tried both "... NOT NULL" and without not null option but I think it is not the solution.
public void addToDb(View view) {
SharedPreferences sharedPreferences = getSharedPreferences("entry",0);
float lastlatitude = sharedPreferences.getFloat("latitude",0f);
float lastlongitude = sharedPreferences.getFloat("longitude",0f);
if (mTitleInput.getText().length() == 0 ||
mEntryInput.getText().length() == 0) {
return;
}
try {
Date a = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("EEE, MMM d, ''yy");
String o = sdf.format(a);
title = mTitleInput.getText().toString();
entry = mEntryInput.getText().toString();
dateStr = o;
image = getApplicationContext().getFilesDir().getAbsolutePath() + String.valueOf(System.currentTimeMillis()) + ".jpg";
rating = mRatingBar.getRating();
latitude = lastlatitude;
longitude = lastlongitude;
} catch (NumberFormatException ex) {
Log.e(LOG_TAG, "Failed to parse party size text to number: " + ex.getMessage());
}
// Add to mDb
addNewEntry(title, entry, dateStr, image, rating, latitude, longitude);
//clear UI text fields
mTitleInput.getText().clear();
mEntryInput.getText().clear();
}
EDIT 1 : Stacktrace.
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.aok.secretdiarywithlock, PID: 29148
java.lang.NullPointerException: Attempt to invoke virtual method 'long android.database.sqlite.SQLiteDatabase.insert(java.lang.String, java.lang.String, android.content.ContentValues)' on a null object reference
at com.aok.secretdiarywithlock.CreateEntry.addNewEntry(CreateEntry.java:157)
at com.aok.secretdiarywithlock.CreateEntry.addToDb(CreateEntry.java:139)
at com.aok.secretdiarywithlock.CreateEntry$1.onClick(CreateEntry.java:93)
at android.view.View.performClick(View.java:6597)
at android.view.View.performClickInternal(View.java:6574)
at android.view.View.access$3100(View.java:778)
at android.view.View$PerformClick.run(View.java:25885)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
EDIT 2 : Error code
private long addNewEntry(String title, String entry, String date, String image, Float rate, Float latitude, Float longitude){
ContentValues cv = new ContentValues();
cv.put(EntryContract.EntryEntry.COLUMN_TITLE,title);
cv.put(EntryContract.EntryEntry.COLUMN_TEXT,entry);
cv.put(EntryContract.EntryEntry.COLUMN_DATE,date);
cv.put(EntryContract.EntryEntry.COLUMN_IMAGE,image);
cv.put(EntryContract.EntryEntry.COLUMN_TEXT,entry);
cv.put(EntryContract.EntryEntry.COLUMN_RATING,rate);
cv.put(EntryContract.EntryEntry.COLUMN_LOCATION_LAT,latitude);
cv.put(EntryContract.EntryEntry.COLUMN_LOCATION_LONG,longitude);
// Next line is throwing error
return mDb.insert(EntryContract.EntryEntry.TABLE_NAME, null, cv);
}
Hi you have to check if they are null for example
dateStr = o == null ? "" : o;
this will check if o is null if it is it will set dateStr to empty, if not it will use o. you can use that for all of your variables.
Related
I've been working on a language learning app for a university project which needs to take vocabulary from an SQLite database.
This was previously working fine, but now it gives me an IndexOutOfBoundsException whenever the app has to communicate with the database. This is without me making any changes to the database or the code being used. I had encountered the problem before and managed to resolve it by rebuilding the entire app from scratch and copying code across from the previous project, but now it has started recurring.
Here is the error message:
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.flagquizgame, PID: 3568
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.flagquizgame/com.example.flagquizgame.ChineseQuizActivity1}: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3835)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
Caused by: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
at java.util.ArrayList.get(ArrayList.java:437)
at com.example.flagquizgame.ChineseQuizActivity1.loadQuestions(ChineseQuizActivity1.java:151)
at com.example.flagquizgame.ChineseQuizActivity1.onCreate(ChineseQuizActivity1.java:65)
at android.app.Activity.performCreate(Activity.java:8207)
at android.app.Activity.performCreate(Activity.java:8191)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3808)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
And here is my code from the relevant classes. The error is thrown when it tries to run the getRandomTenQuestions and getRandomThreeOptions method.
public ArrayList<VocabModel> getRandomTenQuestions(FlagsDatabase fd, int lesson_id, String language)
{
ArrayList<VocabModel> modelArrayList = new ArrayList<>();
SQLiteDatabase liteDatabase = fd.getWritableDatabase();
Cursor cursor = liteDatabase.rawQuery("SELECT * FROM vocabtable WHERE lesson_id = " + lesson_id + " AND language = '" + language + "' ORDER BY " +
"RANDOM () LIMIT 10", null);
int vocabIdIndex = cursor.getColumnIndex("vocab_id");
int vocabIndex = cursor.getColumnIndex("vocab");
int vocabImageIndex = cursor.getColumnIndex("vocab_image");
int lessonIdIndex = cursor.getColumnIndex("lesson_id");
int languageIndex = cursor.getColumnIndex("language");
while (cursor.moveToNext()) {
VocabModel model = new VocabModel(cursor.getInt(vocabIdIndex)
, cursor.getString(vocabIndex)
, cursor.getString(vocabImageIndex)
, cursor.getInt(lessonIdIndex)
, cursor.getString(languageIndex));
modelArrayList.add(model);
}
return modelArrayList;
}
public ArrayList<VocabModel> getRandomThreeOptions(FlagsDatabase fd, int vocab_id, int lesson_id, String language) {
ArrayList<VocabModel> modelArrayList = new ArrayList<>();
SQLiteDatabase liteDatabase = fd.getWritableDatabase();
Cursor cursor = liteDatabase.rawQuery("SELECT * FROM vocabtable WHERE vocab_id != " + vocab_id + " AND lesson_id = " + lesson_id + " AND language = '" + language + "' ORDER BY " +
"RANDOM () LIMIT 3", null);
int vocabIdIndex = cursor.getColumnIndex("vocab_id");
int vocabIndex = cursor.getColumnIndex("vocab");
int vocabImageIndex = cursor.getColumnIndex("vocab_image");
int lessonIdIndex = cursor.getColumnIndex("lesson_id");
int languageIndex = cursor.getColumnIndex("language");
while (cursor.moveToNext()) {
VocabModel model = new VocabModel(cursor.getInt(vocabIdIndex)
, cursor.getString(vocabIndex)
, cursor.getString(vocabImageIndex)
, cursor.getInt(lessonIdIndex)
, cursor.getString(languageIndex));
modelArrayList.add(model);
}
return modelArrayList;
}
I have also considered that it might be related to this class but I'm not sure how:
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE IF NOT EXISTS \"vocabtable\" (\n" +
"\t\"vocab_id\"\tINTEGER,\n" +
"\t\"vocab\"\tTEXT,\n" +
"\t\"vocab_image\"\tTEXT,\n" +
"\t\"lesson_id\"\tINTEGER,\n" +
"\t\"language\"\tTEXT\n" +
");");
}
#Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
db.execSQL("DROP TABLE IF EXISTS vocabtable");
onCreate(db);
}
The only thing I've considered is it could be related to Android Studio updating. I'm not 100% sure but both times the problem has recurred seems to have been after downloading an update. If so, will I just have to rebuild the project from scratch again or is there some other way around it?
Thanks!
This question already has answers here:
What causes a java.lang.ArrayIndexOutOfBoundsException and how do I prevent it?
(26 answers)
Closed 4 years ago.
When size of data is 600, there is no exceltion.
When the size of the data is 800 I am getting following exception, after completing all the iterations and exiting the loop at following line:
'imageAdapter = new ImageAdapter(MainActivity.getAppContext(), posters);'
Issue is not related to splitArray[] which is inside the loop. Please note that it works for smaller size data.
Please help.
FATAL EXCEPTION: main
Process: com.udacityproject.svs.popularmovies, PID: 12517
java.lang.ArrayIndexOutOfBoundsException: length=5; index=5
at com.udacityproject.svs.popularmovies.MainActivity$1.deliverResult(MainActivity.java:130)
at com.udacityproject.svs.popularmovies.MainActivity$1.deliverResult(MainActivity.java:57)
at android.support.v4.content.AsyncTaskLoader.dispatchOnLoadComplete(AsyncTaskLoader.java:255)
at android.support.v4.content.AsyncTaskLoader$LoadTask.onPostExecute(AsyncTaskLoader.java:80)
at android.support.v4.content.ModernAsyncTask.finish(ModernAsyncTask.java:487)
at android.support.v4.content.ModernAsyncTask$InternalHandler.handleMessage(ModernAsyncTask.java:504)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
Constructor for Image Adapter :
public ImageAdapter(#NonNull Context context, #NonNull Poster[] objects){
super(context, 0, objects);
posters = objects;
}
Function:
public void deliverResult(String[] data) {
if (data != null) {
Poster[] posters = new Poster[data.length];
for (int i=0; i<data.length; i++) {
String imagePath = "http://image.tmdb.org/t/p/w185/" ;
int imageId;
String title;
String overview;
String rating;
String releaseDate;
String[] splitArray;
try {
splitArray = data[i].split("[*]");
} catch (PatternSyntaxException e) {
e.printStackTrace();
return;
}
imagePath+=splitArray[2];
imageId = Integer.valueOf(splitArray[0]);
title = splitArray[1];
rating = splitArray[3];
overview = splitArray[4];
releaseDate = splitArray[5];
posters[i] = new Poster( imageId, imagePath, title, overview, rating, releaseDate);
}
imageAdapter = new ImageAdapter(MainActivity.getAppContext(), posters);
mMoviePoster.setAdapter(imageAdapter);
}
}
One of the line included between the 600th and 800th line is incomplete.
Add this following line :
assert splitArray.length > 4 : "Following line lacks a column: " + data[i];
after :
splitArray = data[i].split("[*]");
It should tell you which line lacks the fifth column
I have:
String stringDate = "2017-02-16T15:00:00Z"
I want to convert this into a Date and after it i want to be converted to Long. Here is my code:
private void normalizeDate(ContentValues values) {
// normalize the date value
if (values.containsKey(SmogContract.MeasurementEntry.COLUMN_FROM_DATE_TIME)) {
Date date = convertDateFromStringToDate(values.getAsString(SmogContract.MeasurementEntry.COLUMN_FROM_DATE_TIME));
long fromDateValue = date.getTime();
values.put(SmogContract.MeasurementEntry.COLUMN_FROM_DATE_TIME, SmogContract.normalizeDate(fromDateValue));
}
if (values.containsKey(SmogContract.MeasurementEntry.COLUMN_TILL_DATE_TIME)) {
long fromDateValue = values.getAsLong(SmogContract.MeasurementEntry.COLUMN_TILL_DATE_TIME);
values.put(SmogContract.MeasurementEntry.COLUMN_TILL_DATE_TIME, SmogContract.normalizeDate(fromDateValue));
}
}
private Date convertDateFromStringToDate(String stringDate){
DateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
format.setTimeZone(TimeZone.getTimeZone("GMT"));
Date convertedFromStringDate = null;
try {
convertedFromStringDate = format.parse(stringDate);
} catch (ParseException e) {
e.printStackTrace();
}
return convertedFromStringDate;
}
Here is the exception that i am getting:
java.lang.NullPointerException: Attempt to invoke virtual method 'long java.lang.Long.longValue()' on a null object reference
at com.example.marcin.smog_mapa.data.SmogProvider.normalizeDate(SmogProvider.java:109)
at com.example.marcin.smog_mapa.data.SmogProvider.insert(SmogProvider.java:85)
at android.content.ContentProvider$Transport.insert(ContentProvider.java:263)
at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:163)
at android.os.Binder.execTransact(Binder.java:453)
The format.parse(...) statement fails with a ParseException, leaving convertedFromStringDate at null.
Check your console for the stack trace and make sure stringDate has the correct format.
OK, so it was just an silly mistake in the method.
Here is it done correctly:
private void normalizeDate(ContentValues values) {
// normalize the date value
if (values.containsKey(SmogContract.MeasurementEntry.COLUMN_FROM_DATE_TIME)) {
Date date = convertDateFromStringToDate(values.getAsString(SmogContract.MeasurementEntry.COLUMN_FROM_DATE_TIME));
Log.d("ConvertedDate: ", String.valueOf(date.getTime()));
long fromDateValue = date.getTime();
values.put(SmogContract.MeasurementEntry.COLUMN_FROM_DATE_TIME, SmogContract.normalizeDate(fromDateValue));
}
if (values.containsKey(SmogContract.MeasurementEntry.COLUMN_TILL_DATE_TIME)) {
Date date = convertDateFromStringToDate(values.getAsString(SmogContract.MeasurementEntry.COLUMN_TILL_DATE_TIME));
Log.d("ConvertedDate: ", String.valueOf(date.getTime()));
long fromDateValue = date.getTime();
values.put(SmogContract.MeasurementEntry.COLUMN_TILL_DATE_TIME, SmogContract.normalizeDate(fromDateValue));
}
}
The problem come from
long fromDateValue = values.getAsLong(SmogContract.MeasurementEntry.COLUMN_TILL_DATE_TIME);
Where values is a ContentValues instance.
ContentValues.getAsLong return a null that you store in a long, so it call Long.longValue() leading to this NullPointerException
This is the risk with this auto-boxing / unboxing, if you have
Long wrap_long = null;
long l = wrap_long;
This will compile but will throw a NPE at runtime where
long l = null;
will never compile, for the same reason, a primitive value can't be null
It is good to check the Long value for null when you unbox it.
My app i've created using android studio keeps crashing and I don't know why. Its a weather app and i'm following google's developing android app course, here's the logcat:
07-20 18:19:45.740 16410-16434/com.alexander.sunshine E/ActivityThread﹕ Failed to find provider info for com.alexander.android.sunshine.app
07-20 18:19:45.748 16410-16434/com.alexander.sunshine E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
Process: com.alexander.sunshine, PID: 16410
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:304)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'boolean android.database.Cursor.moveToFirst()' on a null object reference
at com.alexander.sunshine.app.FetchWeatherTask.addLocation(FetchWeatherTask.java:109)
at com.alexander.sunshine.app.FetchWeatherTask.getWeatherDataFromJson(FetchWeatherTask.java:214)
at com.alexander.sunshine.app.FetchWeatherTask.doInBackground(FetchWeatherTask.java:414)
at com.alexander.sunshine.app.FetchWeatherTask.doInBackground(FetchWeatherTask.java:34)
at android.os.AsyncTask$2.call(AsyncTask.java:292)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
And here's the FetchWeatherTask.java:
package com.alexander.sunshine.app;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.DatabaseUtils;
import android.net.Uri;
import android.os.AsyncTask;
import android.preference.PreferenceManager;
import android.text.format.Time;
import android.util.Log;
import android.widget.ArrayAdapter;
import com.alexander.sunshine.R;
import com.alexander.sunshine.app.data.WeatherContract;
import com.alexander.sunshine.app.data.WeatherContract.WeatherEntry;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Vector;
public class FetchWeatherTask extends AsyncTask<String, Void, String[]> {
private final String LOG_TAG = FetchWeatherTask.class.getSimpleName();
private ArrayAdapter<String> mForecastAdapter;
private final Context mContext;
public FetchWeatherTask(Context context, ArrayAdapter<String> forecastAdapter) {
mContext = context;
mForecastAdapter = forecastAdapter;
}
private boolean DEBUG = true;
/* The date/time conversion code is going to be moved outside the asynctask later,
* so for convenience we're breaking it out into its own method now.
*/
private String getReadableDateString(long time){
// Because the API returns a unix timestamp (measured in seconds),
// it must be converted to milliseconds in order to be converted to valid date.
Date date = new Date(time);
SimpleDateFormat format = new SimpleDateFormat("E, MMM d");
return format.format(date).toString();
}
/**
* Prepare the weather high/lows for presentation.
*/
private String formatHighLows(double high, double low) {
// Data is fetched in Celsius by default.
// If user prefers to see in Fahrenheit, convert the values here.
// We do this rather than fetching in Fahrenheit so that the user can
// change this option without us having to re-fetch the data once
// we start storing the values in a database.
SharedPreferences sharedPrefs =
PreferenceManager.getDefaultSharedPreferences(mContext);
String unitType = sharedPrefs.getString(
mContext.getString(R.string.pref_units_key),
mContext.getString(R.string.pref_units_metric));
if (unitType.equals(mContext.getString(R.string.pref_units_imperial))) {
high = (high * 1.8) + 32;
low = (low * 1.8) + 32;
} else if (!unitType.equals(mContext.getString(R.string.pref_units_metric))) {
Log.d(LOG_TAG, "Unit type not found: " + unitType);
}
// For presentation, assume the user doesn't care about tenths of a degree.
long roundedHigh = Math.round(high);
long roundedLow = Math.round(low);
String highLowStr = roundedHigh + "/" + roundedLow;
return highLowStr;
}
/**
* Helper method to handle insertion of a new location in the weather database.
*
* #param locationSetting The location string used to request updates from the server.
* #param cityName A human-readable city name, e.g "Mountain View"
* #param lat the latitude of the city
* #param lon the longitude of the city
* #return the row ID of the added location.
*/
long addLocation(String locationSetting, String cityName, double lat, double lon) {
long locationId;
// First, check if the location with this city name exists in the db
Cursor locationCursor = mContext.getContentResolver().query(
WeatherContract.LocationEntry.CONTENT_URI,
new String[]{WeatherContract.LocationEntry._ID},
WeatherContract.LocationEntry.COLUMN_LOCATION_SETTING + " = ?",
new String[]{locationSetting},
null);
if (locationCursor.moveToFirst()) {
int locationIdIndex = locationCursor.getColumnIndex(WeatherContract.LocationEntry._ID);
locationId = locationCursor.getLong(locationIdIndex);
} else {
// Now that the content provider is set up, inserting rows of data is pretty simple.
// First create a ContentValues object to hold the data you want to insert.
ContentValues locationValues = new ContentValues();
// Then add the data, along with the corresponding name of the data type,
// so the content provider knows what kind of value is being inserted.
locationValues.put(WeatherContract.LocationEntry.COLUMN_CITY_NAME, cityName);
locationValues.put(WeatherContract.LocationEntry.COLUMN_LOCATION_SETTING, locationSetting);
locationValues.put(WeatherContract.LocationEntry.COLUMN_COORD_LAT, lat);
locationValues.put(WeatherContract.LocationEntry.COLUMN_COORD_LONG, lon);
// Finally, insert location data into the database.
Uri insertedUri = mContext.getContentResolver().insert(
WeatherContract.LocationEntry.CONTENT_URI,
locationValues
);
// The resulting URI contains the ID for the row. Extract the locationId from the Uri.
locationId = ContentUris.parseId(insertedUri);
}
locationCursor.close();
// Wait, that worked? Yes!
return locationId;
}
/*
Students: This code will allow the FetchWeatherTask to continue to return the strings that
the UX expects so that we can continue to test the application even once we begin using
the database.
*/
String[] convertContentValuesToUXFormat(Vector<ContentValues> cvv) {
// return strings to keep UI functional for now
String[] resultStrs = new String[cvv.size()];
for ( int i = 0; i < cvv.size(); i++ ) {
ContentValues weatherValues = cvv.elementAt(i);
String highAndLow = formatHighLows(
weatherValues.getAsDouble(WeatherEntry.COLUMN_MAX_TEMP),
weatherValues.getAsDouble(WeatherEntry.COLUMN_MIN_TEMP));
resultStrs[i] = getReadableDateString(
weatherValues.getAsLong(WeatherEntry.COLUMN_DATE)) +
" - " + weatherValues.getAsString(WeatherEntry.COLUMN_SHORT_DESC) +
" - " + highAndLow;
}
return resultStrs;
}
/**
* Take the String representing the complete forecast in JSON Format and
* pull out the data we need to construct the Strings needed for the wireframes.
*
* Fortunately parsing is easy: constructor takes the JSON string and converts it
* into an Object hierarchy for us.
*/
private String[] getWeatherDataFromJson(String forecastJsonStr,
String locationSetting)
throws JSONException {
// Now we have a String representing the complete forecast in JSON Format.
// Fortunately parsing is easy: constructor takes the JSON string and converts it
// into an Object hierarchy for us.
// These are the names of the JSON objects that need to be extracted.
// Location information
final String OWM_CITY = "city";
final String OWM_CITY_NAME = "name";
final String OWM_COORD = "coord";
// Location coordinate
final String OWM_LATITUDE = "lat";
final String OWM_LONGITUDE = "lon";
// Weather information. Each day's forecast info is an element of the "list" array.
final String OWM_LIST = "list";
final String OWM_PRESSURE = "pressure";
final String OWM_HUMIDITY = "humidity";
final String OWM_WINDSPEED = "speed";
final String OWM_WIND_DIRECTION = "deg";
// All temperatures are children of the "temp" object.
final String OWM_TEMPERATURE = "temp";
final String OWM_MAX = "max";
final String OWM_MIN = "min";
final String OWM_WEATHER = "weather";
final String OWM_DESCRIPTION = "main";
final String OWM_WEATHER_ID = "id";
try {
JSONObject forecastJson = new JSONObject(forecastJsonStr);
JSONArray weatherArray = forecastJson.getJSONArray(OWM_LIST);
JSONObject cityJson = forecastJson.getJSONObject(OWM_CITY);
String cityName = cityJson.getString(OWM_CITY_NAME);
JSONObject cityCoord = cityJson.getJSONObject(OWM_COORD);
double cityLatitude = cityCoord.getDouble(OWM_LATITUDE);
double cityLongitude = cityCoord.getDouble(OWM_LONGITUDE);
long locationId = addLocation(locationSetting, cityName, cityLatitude, cityLongitude);
// Insert the new weather information into the database
Vector<ContentValues> cVVector = new Vector<ContentValues>(weatherArray.length());
// OWM returns daily forecasts based upon the local time of the city that is being
// asked for, which means that we need to know the GMT offset to translate this data
// properly.
// Since this data is also sent in-order and the first day is always the
// current day, we're going to take advantage of that to get a nice
// normalized UTC date for all of our weather.
Time dayTime = new Time();
dayTime.setToNow();
// we start at the day returned by local time. Otherwise this is a mess.
int julianStartDay = Time.getJulianDay(System.currentTimeMillis(), dayTime.gmtoff);
// now we work exclusively in UTC
dayTime = new Time();
for(int i = 0; i < weatherArray.length(); i++) {
// These are the values that will be collected.
long dateTime;
double pressure;
int humidity;
double windSpeed;
double windDirection;
double high;
double low;
String description;
int weatherId;
// Get the JSON object representing the day
JSONObject dayForecast = weatherArray.getJSONObject(i);
// Cheating to convert this to UTC time, which is what we want anyhow
dateTime = dayTime.setJulianDay(julianStartDay+i);
pressure = dayForecast.getDouble(OWM_PRESSURE);
humidity = dayForecast.getInt(OWM_HUMIDITY);
windSpeed = dayForecast.getDouble(OWM_WINDSPEED);
windDirection = dayForecast.getDouble(OWM_WIND_DIRECTION);
// Description is in a child array called "weather", which is 1 element long.
// That element also contains a weather code.
JSONObject weatherObject =
dayForecast.getJSONArray(OWM_WEATHER).getJSONObject(0);
description = weatherObject.getString(OWM_DESCRIPTION);
weatherId = weatherObject.getInt(OWM_WEATHER_ID);
// Temperatures are in a child object called "temp". Try not to name variables
// "temp" when working with temperature. It confuses everybody.
JSONObject temperatureObject = dayForecast.getJSONObject(OWM_TEMPERATURE);
high = temperatureObject.getDouble(OWM_MAX);
low = temperatureObject.getDouble(OWM_MIN);
ContentValues weatherValues = new ContentValues();
weatherValues.put(WeatherEntry.COLUMN_LOC_KEY, locationId);
weatherValues.put(WeatherEntry.COLUMN_DATE, dateTime);
weatherValues.put(WeatherEntry.COLUMN_HUMIDITY, humidity);
weatherValues.put(WeatherEntry.COLUMN_PRESSURE, pressure);
weatherValues.put(WeatherEntry.COLUMN_WIND_SPEED, windSpeed);
weatherValues.put(WeatherEntry.COLUMN_DEGREES, windDirection);
weatherValues.put(WeatherEntry.COLUMN_MAX_TEMP, high);
weatherValues.put(WeatherEntry.COLUMN_MIN_TEMP, low);
weatherValues.put(WeatherEntry.COLUMN_SHORT_DESC, description);
weatherValues.put(WeatherEntry.COLUMN_WEATHER_ID, weatherId);
cVVector.add(weatherValues);
}
// add to database
if ( cVVector.size() > 0 ) {
ContentValues[] cvArray = new ContentValues[cVVector.size()];
cVVector.toArray(cvArray);
mContext.getContentResolver().bulkInsert(WeatherEntry.CONTENT_URI, cvArray);
}
// Sort order: Ascending, by date.
String sortOrder = WeatherEntry.COLUMN_DATE + " ASC";
Uri weatherForLocationUri = WeatherEntry.buildWeatherLocationWithStartDate(
locationSetting, System.currentTimeMillis());
// Students: Uncomment the next lines to display what what you stored in the bulkInsert
Cursor cur = mContext.getContentResolver().query(weatherForLocationUri,
null, null, null, sortOrder);
cVVector = new Vector<ContentValues>(cur.getCount());
if ( cur.moveToFirst() ) {
do {
ContentValues cv = new ContentValues();
DatabaseUtils.cursorRowToContentValues(cur, cv);
cVVector.add(cv);
} while (cur.moveToNext());
}
Log.d(LOG_TAG, "FetchWeatherTask Complete. " + cVVector.size() + " Inserted");
String[] resultStrs = convertContentValuesToUXFormat(cVVector);
return resultStrs;
} catch (JSONException e) {
Log.e(LOG_TAG, e.getMessage(), e);
e.printStackTrace();
}
return null;
}
#Override
protected String[] doInBackground(String... params) {
// If there's no zip code, there's nothing to look up. Verify size of params.
if (params.length == 0) {
return null;
}
String locationQuery = params[0];
// These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
// Will contain the raw JSON response as a string.
String forecastJsonStr = null;
String format = "json";
String units = "metric";
int numDays = 14;
try {
// Construct the URL for the OpenWeatherMap query
// Possible parameters are avaiable at OWM's forecast API page, at
// http://openweathermap.org/API#forecast
final String FORECAST_BASE_URL =
"http://api.openweathermap.org/data/2.5/forecast/daily?";
final String QUERY_PARAM = "q";
final String FORMAT_PARAM = "mode";
final String UNITS_PARAM = "units";
final String DAYS_PARAM = "cnt";
Uri builtUri = Uri.parse(FORECAST_BASE_URL).buildUpon()
.appendQueryParameter(QUERY_PARAM, params[0])
.appendQueryParameter(FORMAT_PARAM, format)
.appendQueryParameter(UNITS_PARAM, units)
.appendQueryParameter(DAYS_PARAM, Integer.toString(numDays))
.build();
URL url = new URL(builtUri.toString());
// Create the request to OpenWeatherMap, and open the connection
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// Read the input stream into a String
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
forecastJsonStr = buffer.toString();
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the weather data, there's no point in attemping
// to parse it.
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e(LOG_TAG, "Error closing stream", e);
}
}
}
try {
return getWeatherDataFromJson(forecastJsonStr, locationQuery);
} catch (JSONException e) {
Log.e(LOG_TAG, e.getMessage(), e);
e.printStackTrace();
}
// This will only happen if there was an error getting or parsing the forecast.
return null;
}
#Override
protected void onPostExecute(String[] result) {
if (result != null && mForecastAdapter != null) {
mForecastAdapter.clear();
for(String dayForecastStr : result) {
mForecastAdapter.add(dayForecastStr);
}
// New data is back from the server. Hooray!
}
}
}
As the stack trace says, you're trying to call moveToFirst() on a null reference. locationCursor is the only object you're calling that method on, so it must be null.
The docs for query() say that it can return null, so you'll should null check that object, and you should also check your invocation of query() to try to understand why it's returning null.
Clearly, in your addLocation method, the locationCursor you get by calling Cursor locationCursor = mContext.getContentResolver().query(...) is null, which causes the crash when you call locationCursor.moveToFirst() just after that.
I suggest to check out this problem's accepted answer. The problem might be that the query is empty.
In any case, you should always check whether the Cursor is null before you apply methods to it, and deal with that case somehow by alerting the user.
The method could look like this:
long addLocation(String locationSetting, String cityName, double lat, double lon) {
long locationId;
// First, check if the location with this city name exists in the db
Cursor locationCursor = mContext.getContentResolver().query(
WeatherContract.LocationEntry.CONTENT_URI,
new String[]{WeatherContract.LocationEntry._ID},
WeatherContract.LocationEntry.COLUMN_LOCATION_SETTING + " = ?",
new String[]{locationSetting},
null);
if (locationCursor != null) {
if (locationCursor.moveToFirst()) {
int locationIdIndex = locationCursor.getColumnIndex(WeatherContract.LocationEntry._ID);
locationId = locationCursor.getLong(locationIdIndex);
locationCursor.close();
return locationId;
}
}
// Now that the content provider is set up, inserting rows of data is pretty simple.
// First create a ContentValues object to hold the data you want to insert.
ContentValues locationValues = new ContentValues();
// Then add the data, along with the corresponding name of the data type,
// so the content provider knows what kind of value is being inserted.
locationValues.put(WeatherContract.LocationEntry.COLUMN_CITY_NAME, cityName);
locationValues.put(WeatherContract.LocationEntry.COLUMN_LOCATION_SETTING, locationSetting);
locationValues.put(WeatherContract.LocationEntry.COLUMN_COORD_LAT, lat);
locationValues.put(WeatherContract.LocationEntry.COLUMN_COORD_LONG, lon);
// Finally, insert location data into the database.
Uri insertedUri = mContext.getContentResolver().insert(
WeatherContract.LocationEntry.CONTENT_URI,
locationValues
);
// The resulting URI contains the ID for the row. Extract the locationId from the Uri.
locationId = ContentUris.parseId(insertedUri);
locationCursor.close();
// Wait, that worked? Yes!
return locationId;
}
I am passing and showing values from one activity to another activity, and making file name using those string like this:
AU_20140312_160107_65.jpg
AU - simple prefix
20140312_160107 - yyyyMMdd_HHmmss
6 - event_id (getting from LoginActivity.java)
5 - operative_id (getting from LoginActivity.java)
see my code below:
LoginActivity.java:
static SharedPreferences sharedprefs;
static String event_id, operative_id ;
sharedprefs = getApplicationContext().getSharedPreferences(
"com.example.app", Context.MODE_PRIVATE);
Intent intent = getIntent();
event_id = intent.getStringExtra("event_id");
sharedprefs.edit().putString("EVENT_ID", event_id).commit();
operative_id = intent.getStringExtra("operative_id");
sharedprefs.edit().putString("OPERATIVE_ID", operative_id).commit();
CameraLauncherActivity.java:
static File getOutputMediaFile() {
String event_ID = LoginActivity.sharedprefs.getString("EVENT_ID", null);
Log.d("shared >>> eventID : ", event_ID);
String operative_ID = LoginActivity.sharedprefs.getString("OPERATIVE_ID", null);
Log.d("shared >>> operativeID : ", operative_ID);
timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
.format(new Date());
// file name
mediaFile = new File(LoginActivity.mediaStorageDir.getPath() + File.separator
+ "AU_" + timeStamp + "_" + event_ID + operative_ID + ".jpg");
return mediaFile;
}
when launching first time, Log says:
shared >>> eventID :(29917): 12
shared >>> operativeID :(29917): 4
like you can see above, everything works fine, and getting eventID and operativeID using log as well
but once i will launch my app again, after closing it, and caputre image, then getting NPE and Log :
FATAL EXCEPTION: main
java.lang.NullPointerException: println needs a message
at android.util.Log.println_native(Native Method)
at android.util.Log.d(Log.java:155)
app.mac.Camera.CameraLauncherActivity.getOutputMediaFile(CameraLauncherActivity.java:386)
at app.mac.Camera.CameraLauncherActivity$2.onPictureTaken(CameraLauncherActivity.java:362)
at android.hardware.Camera$EventHandler.handleMessage(Camera.java:789)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4921)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1036)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:803)
at dalvik.system.NativeStart.main(Native Method)
Instead of assigning the values directly to the variables event_id and operative_id store them in the db or preferences.
Instead of directly assigning like this this :
event_id = intent.getStringExtra("event_id");
operative_id = intent.getStringExtra("operative_id");
check the intent.getStringExtra("event_id") and intent.getStringExtra("operative_id") for null.
If null fetch from stored values.
If not null assign to variables and overwrite stored values with the new one for next time.
//Initialization
SharedPreferences _mypref = getApplicationContext().getSharedPreferences("mypref", 0);
//store data in shared preferences
Editor editor = _mypref.edit();
//Storing boolean - true/false;
editor.putBoolean("key_name", true);
//Storing string
editor.putString("key_name", "string value");
//Storing integer
editor.putInt("key_name", "int value");
//Storing float
editor.putFloat("key_name", "float value");
//Storing long
editor.putLong("key_name", "long value");
//commit changes
editor.commit();
// retrive data
//getting String
_mypref .getString("key_name", null);
//getting Integer
_mypref .getInt("key_name", null);
//getting Float
_mypref .getFloat("key_name", null);
//getting Long
_mypref .getLong("key_name", null);
//getting boolean
_mypref.getBoolean("key_name", null);
//remove Data
editor.remove("name");
editor.commit();
//Clear all Data
editor.clear();
editor.commit();