Null Pointer Exception while working with fragments in android

Question

I am working on functionality in which I want to send data from send fragment to another. I am setting arguments in one fragment say "A Fragment" and getting it from another say "B Fragment" but the problem is this when I jump to "B fragment" from "C Fragment" which does not contain that value then my app crashes and throws error java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference

My Code:

Fragment A

     Bundle bundle = new Bundle();
            bundle.putString("advisor_id", advisor_id);

            FragmentMicroLearningArticlesList fragmentMicroLearningArticlesList = new FragmentMicroLearningArticlesList();
            fragmentMicroLearningArticlesList.setArguments(bundle);
            android.support.v4.app.FragmentManager fragmentManager = getActivity().getSupportFragmentManager();

            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
            fragmentTransaction.replace(R.id.frame, fragmentMicroLearningArticlesList);
            fragmentTransaction.addToBackStack(null);
            fragmentTransaction.commit();

Fragment B

      String  advisor_id = "";
   if(getArguments().getString("advisor_id") != null )
    {
        advisor_id = getArguments().getString("advisor_id");
    }
    else {
        advisor_id = "";
    }

It is pretty clear that you cannot read the arguments when they have not been set before. What are you actually asking? — Henry, Mar 30 '18 at 12:29
Set the Arguments in fragment B also. And get in fragment B. — Ankita, Mar 30 '18 at 12:30
Just like henry said your arguments is null Maybe you should add a check if your arguments are null then don't do anything if not get the value ? — Umair, Mar 30 '18 at 12:30
How can I handle this that If I am getting value from one but not from another — Android Developer, Mar 30 '18 at 12:31
@Umair I am checking null check the above code but it is crashing — Android Developer, Mar 30 '18 at 12:32
where you wrote code for get value from argument? post your full code of fragment B — Niranj Patel, Mar 30 '18 at 12:32
@AndroidDeveloper well your check is for the string value not for the arguments :) — Umair, Mar 30 '18 at 12:33
Possible duplicate of [What is a NullPointerException, and how do I fix it?](https://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — AskNilesh, Mar 30 '18 at 12:35

score 2 · Answer 1 · answered Mar 30 '18 at 12:33

2

As the error says check if argument is null...

if( getArguments() != null && getArguments().getString("advisor_id") != null )

answered Mar 30 '18 at 12:33

Samuel Eminet

4,647
2
18
32

@AndroidDeveloper are you able to get value from bundle? – Niranj Patel Mar 30 '18 at 12:37
Very Good... enjoy – Niranj Patel Mar 30 '18 at 12:40

score 1 · Answer 2 · answered Mar 30 '18 at 12:37

1

Fragment B

  String  advisor_id = "";
   if(getArguments()!= null )
    {
        advisor_id = getArguments().getString("advisor_id");
    }
    else {
        advisor_id = "";
    }

answered Mar 30 '18 at 12:37

Ankita

1,129
1
8
15

What's the point of the `else` statement? You've already initialised the `String` - this would only make sense if you have `final String advisor_id;` instead of `String advisor_id = "";` and even then `advisor_id` could still be initialised to `null` – Mark Mar 30 '18 at 13:07

Null Pointer Exception while working with fragments in android

2 Answers2