NullPointerException received when calling Bundle.getParcelable

Question

I have a problem that I am trying to solve for few hours but cannot solve it and I need some help. I am trying to retrieve URL strings from a Login activity and trying to pass it to the Main activity using a parcelable object but I receive NullPointerException on getParcelable method.

Following is the code that creates the URL parcelable object and puts it to Intent and calls the Main activity

 public void onGetPremiumURLCompletion(List<String> urls){
    String[] urlList = new String[urls.size()];
    for (int i = 0; i < urls.size(); i++) {urlList[i] = urls.get(i);}
    URL urlParcelable = new URL(urlList);
    for (int i = 0; i < urlParcelable.getUrls().length; i++) {Log.w("url from parcelable",urlParcelable.getUrls()[i]);}
    Intent intent = new Intent(this,Home.class);
    intent.putExtra("PremiumURLList",urlParcelable);
    progress.dismiss();
    startActivity(intent);

}

And the following is the URL parcelable class

public class URL implements Parcelable {
private String[] urls;

public static final Parcelable.Creator<URL> CREATOR = new Parcelable.Creator<URL>() {
    public URL createFromParcel(Parcel in) {
        return new URL(in);
    }

    public URL[] newArray(int size) {
        return new URL[size];
    }
};

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

@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeStringArray(urls);
}

private URL(Parcel in) {
    in.readStringArray(urls);
}

public URL(String[] urlList){
    urls = urlList;
}

public String[] getUrls() {
    return urls;
}}

Here is how I am receiving the parcelable object from the intent.

Bundle b = getIntent().getExtras();
    URL urlList = b.getParcelable("PremiumURLList");

I am getting the following error on getParcelable line

Caused by: java.lang.NullPointerException
        at android.os.Parcel.readStringArray(Parcel.java:962)
        at com.rayat.pricewiz.entity.URL.<init>(URL.java:33)
        at com.rayat.pricewiz.entity.URL.<init>(URL.java:9)
        at com.rayat.pricewiz.entity.URL$1.createFromParcel(URL.java:14)
        at com.rayat.pricewiz.entity.URL$1.createFromParcel(URL.java:12)
        at android.os.Parcel.readParcelable(Parcel.java:2104)
        at android.os.Parcel.readValue(Parcel.java:2013)
        at android.os.Parcel.readArrayMapInternal(Parcel.java:2314)
        at android.os.Bundle.unparcel(Bundle.java:249)
        at android.os.Bundle.getParcelable(Bundle.java:1206)
        at com.rayat.pricewiz.view.activity.tabhome.Home.onCreate(Home.java:72)
        at android.app.Activity.performCreate(Activity.java:5426)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)

Please help.

Thanks

Answer 1

Your problem is here:

private URL(Parcel in) {
    in.readStringArray(urls);
}

urls is null at this point, and the readStringArray(String[]) method expects a parameter that is non-null, and the same length as the resulting read array. I find that method to be nearly useless as it doesn't really work unless you know in advance a fixed size for the array. Alternatively, I suggest you use createStringArray():

private URL(Parcel in) {
    urls = in.createStringArray();
}