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Android Android Lists and Adapters (2015) Using Parcelable Data Retrieving Parcelable Data

Kyle Derrick
Kyle Derrick
7,746 Points

java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)'

Hello,

Thank you in advance for any help given.

I am getting this error when I attempt to run my weather app. I realize it is due to the "iconString" object on Forecast.Java being null, but I cannot locate where I made an error that is causing it to be null.

Here is the error log:

FATAL EXCEPTION: main Process: com.epicodus.theweatherapp, PID: 2980 java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at com.epicodus.theweatherapp.weather.Forecast.getIconId(Forecast.java:47)
at com.epicodus.theweatherapp.weather.Day.getIconId(Day.java:62)
at com.epicodus.theweatherapp.Adapters.DayAdapter.getView(DayAdapter.java:58)
at android.widget.AbsListView.obtainView(AbsListView.java:2346)
at android.widget.ListView.makeAndAddView(ListView.java:1875)
at android.widget.ListView.fillDown(ListView.java:702)
at android.widget.ListView.fillFromTop(ListView.java:763)
at android.widget.ListView.layoutChildren(ListView.java:1684)
at android.widget.AbsListView.onLayout(AbsListView.java:2148)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1079)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at com.android.internal.policy.PhoneWindow$DecorView.onLayout(PhoneWindow.java:2678)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2171)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1931)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:606)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
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)

I will also post my Forecast.Java, Day.Java and DayAdapter.Java (as I believe one of those is where the error lies).

public class Forecast {

    public static final String TAG = Forecast.class.getSimpleName();

    private Current mCurrent;
    private Hour[] mHourlyForecast;
    private Day[] mDailyForecast;

    public Current getCurrent() {
        return mCurrent;
    }

    public void setCurrent(Current mCurrent) {
        this.mCurrent = mCurrent;
    }

    public Hour[] getHourlyForecast() {
        return mHourlyForecast;
    }

    public void setHourlyForecast(Hour[] mHourlyForecast) {
        this.mHourlyForecast = mHourlyForecast;
    }

    public Day[] getDailyForecast() {
        return mDailyForecast;
    }

    public void setDailyForecast(Day[] mDailyForecast) {
        this.mDailyForecast = mDailyForecast;
    }

    public static int getIconId(String iconString) {

        int iconId = R.mipmap.clear_day;

        if (iconString.equals("clear-day")) {
            iconId = R.mipmap.clear_day;
        }
        else if (iconString.equals("clear-night")) {
            iconId = R.mipmap.clear_night;
        }
        else if (iconString.equals("rain")) {
            iconId = R.mipmap.rain;
        }
        else if (iconString.equals("snow")) {
            iconId = R.mipmap.snow;
        }
        else if (iconString.equals("sleet")) {
            iconId = R.mipmap.sleet;
        }
        else if (iconString.equals("wind")) {
            iconId = R.mipmap.wind;
        }
        else if (iconString.equals("fog")) {
            iconId = R.mipmap.fog;
        }
        else if (iconString.equals("cloudy")) {
            iconId = R.mipmap.cloudy;
        }
        else if (iconString.equals("partly-cloudy-day")) {
            iconId = R.mipmap.partly_cloudy;
        }
        else if (iconString.equals("partly-cloudy-night")) {
            iconId = R.mipmap.cloudy_night;
        }
        Log.d(TAG, iconId + ": THIS SHOULD NOT BE NULL BUT IT MAY BE" );
        return iconId;
    }
}
public class Day implements Parcelable {
    private long mTime;
    private String mSummary;
    private double mTemperatureMax;
    private String mIcon;
    private String mTimezone;

    public static final String TAG = Day.class.getSimpleName();

    public long getTime() {
        return mTime;
    }

    public void setTime(long mTime) {
        this.mTime = mTime;
    }

    public String getSummary() {
        return mSummary;
    }

    public void setSummary(String mSummary) {
        this.mSummary = mSummary;
    }

    public int getTemperatureMax() {

        return (int)Math.round(mTemperatureMax);
    }

    public void setTemperatureMax(double mTemperatureMax) {
        this.mTemperatureMax = mTemperatureMax;
    }

    public String getIcon() {
        return mIcon;
    }

    public void setIcon(String mIcon) {
        this.mIcon = mIcon;
    }

    public String getTimezone() {
        return mTimezone;
    }

    public void setTimezone(String mTimezone) {
        this.mTimezone = mTimezone;
    }

    public int getIconId() {
        Log.d(TAG, Forecast.getIconId(mIcon) + "");
        return Forecast.getIconId(mIcon);
    }



    public String getDayOfTheWeek() {
        SimpleDateFormat formatter = new SimpleDateFormat("EEEE");
        formatter.setTimeZone(TimeZone.getTimeZone(mTimezone));
        Date dateTime = new Date(mTime * 1000);
        return formatter.format(dateTime);
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeLong(mTime);
        dest.writeString(mSummary);
        dest.writeDouble(mTemperatureMax);
        dest.writeString(mIcon);
        dest.writeString(mTimezone);
    }

    private Day(Parcel in) {
        mTime = in.readLong();
        mSummary = in.readString();
        mTemperatureMax = in.readDouble();
        mIcon = in.readString();
        mTimezone = in.readString();
    }

    public Day() {

    }

    public static final Creator<Day> CREATOR = new Creator<Day>() {
        @Override
        public Day createFromParcel(Parcel source) {
            return new Day(source);
        }

        @Override
        public Day[] newArray(int size) {
            return new Day[size];
        }
    };
}
public class DayAdapter extends BaseAdapter {

    private Context mContext;
    private Day[] mDays;

    public DayAdapter(Context context, Day[] days) {
        mContext = context;
        mDays = days;
    }

    @Override
    public int getCount() {
        return mDays.length;
    }

    @Override
    public Object getItem(int position) {
        return mDays[position];
    }

    @Override
    public long getItemId(int position) {
        return 0; //Will not be used. Can be used to tag items for easy reference
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if(convertView == null) {
            //brand new
            convertView = LayoutInflater.from(mContext).inflate(R.layout.daily_list_item, null);
            holder = new ViewHolder();
            holder.iconImageView = (ImageView) convertView.findViewById(R.id.iconImageView);
            holder.temperatureLabelTextView = (TextView) convertView.findViewById(R.id.temperatureLabelTextView);
            holder.dayLabelTextView = (TextView) convertView.findViewById(R.id.dayNameLabelTextView);

            convertView.setTag(holder);
        }
        else {
            holder = (ViewHolder) convertView.getTag();
        }

        Day day = mDays[position];
        holder.iconImageView.setImageResource(day.getIconId());
        holder.temperatureLabelTextView.setText(day.getTemperatureMax() + "");
        holder.dayLabelTextView.setText(day.getDayOfTheWeek());



        return convertView;
    }

    private static class ViewHolder {
        ImageView iconImageView;
        TextView temperatureLabelTextView;
        TextView dayLabelTextView;

    }
}

Thank you again and please let me know if any additional info is needed to provide advice.

3 Answers

Kyle Derrick
Kyle Derrick
7,746 Points

Lucas,

For me, it was an issue on MainActivity. When creating the day object, I had neglected to get the icon String. Once I added: "day.setIcon(jsonDay.getString("icon"));" it worked as desired.

Hope this helps

Lucas Assalti
Lucas Assalti
3,459 Points

This worked for me. Thank u Kyle :)

Kyle Derrick
Kyle Derrick
7,746 Points

Nevermind.

I have figured it out. Sorry if anyone wasted time looking at this.

Lucas Assalti
Lucas Assalti
3,459 Points

Hey, i have this error too, what do you did to resolve?

Joseph Ngo
Joseph Ngo
10,020 Points

I am having the same problem and it arises because the daily forecast array is empty when it gets parced to DailyForecastActivity. I don't know how to fix this so any help would be appreciated.