Data not saved in shared preferences on Commit

Question

I am trying to save the data received by the fragment into a shared preference so that I can reuse the data stored in shared preference when the same fragment is recreated. But somehow the data is not getting saved and the default value of preference is returned to my fragment. Below is the code. Fragment implementing SharePreference

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

public class StreamFragment extends Fragment {

    public String streamUrl=null;
    TextView textView;
    public static final String playerData="pData";
    SharedPreferences playerSettings;
    public StreamFragment(){};

   @Override
    public void onCreate(Bundle state) {
        super.onCreate(state);
        SharedPreferences playerSettings = getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE);
        streamUrl = playerSettings.getString(streamUrl,"No Link Found");
    }

    @Override
    public View onCreateView( LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
        View view =  inflater.inflate(R.layout.fragment_stream, container, false);
        playerSettings = getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE);
        streamUrl = playerSettings.getString("streamLink","No Link Found");
        //getData();
        Toast.makeText(getActivity(),"Stream Saved"+streamUrl,Toast.LENGTH_LONG).show();
        return view;
    }       

    public void getUrl(String data)
    {
        streamUrl=data;
        playerSettings = this.getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = playerSettings.edit();
        editor.putString("streamLink", streamUrl);
        editor.commit();
        Toast.makeText(getActivity(),"Stream Saved"+streamUrl,Toast.LENGTH_LONG).show();
    }
}

Thanks in advance!

Answer 1

you are using two SharedPreferences playerSettings; one globally and one in onCreate and you are using upper one which is not initialized

   import android.content.Context;
    import android.content.SharedPreferences;
    import android.os.Bundle;
    import android.support.v4.app.Fragment;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;
    import android.widget.Toast;

    public class StreamFragment extends Fragment {

        public String streamUrl=null;
        TextView textView;
        public static final String playerData="pData";
        SharedPreferences playerSettings;
        public StreamFragment(){};

       @Override
        public void onCreate(Bundle state) {
            super.onCreate(state);
            playerSettings = getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE);
            streamUrl = playerSettings.getString("streamLink","No Link Found");
        }

        @Override
        public View onCreateView( LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
            View view =  inflater.inflate(R.layout.fragment_stream, container, false);
            playerSettings = getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE);
            streamUrl = playerSettings.getString("streamLink","No Link Found");
            //getData();
            Toast.makeText(getActivity(),"Stream Saved"+streamUrl,Toast.LENGTH_LONG).show();
            return view;
        }       

        public void getUrl(String data)
        {
            streamUrl=data;
            playerSettings = this.getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE);
            SharedPreferences.Editor editor = playerSettings.edit();
            editor.putString("streamLink", streamUrl);
            editor.commit();
            Toast.makeText(getActivity(),"Stream Saved"+streamUrl,Toast.LENGTH_LONG).show();
        }
    }

Answer 2

Instead of streamUrl = playerSettings.getString(streamUrl,"No Link Found");

You should use

streamUrl = playerSettings.getString("streamLink","No Link Found");

And also use apply instead of commit

Answer 3

Your key to the preference value is not correct. Note the below line.

streamUrl = playerSettings.getString(streamUrl,"No Link Found");

Use some constant value as key.

private static final String STREAM_URL = "stream_url";

and the use the constant as key as mentioned below.

streamUrl = playerSettings.getString(STREAM_URL,"No Link Found");

Answer 4

I try to explain the point here:

Refer to this image:

As you can see, the onCreate is fired before the onCreateview.

Lets analyze your code:

public class StreamFragment extends Fragment {

    public String streamUrl=null;
    TextView textView;
    public static final String playerData="pData";
    SharedPreferences playerSettings;
    public StreamFragment(){};

Here, your streamUrl is null.

 @Override
    public void onCreate(Bundle state) {
        super.onCreate(state);
        /*SharedPreferences -- no needed*/playerSettings = getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE);
        streamUrl = playerSettings.getString(/*streamUrl -- replace with a key value*/,"No Link Found");
    }

That's the first method fired. here you are trying to get a String from sharedPref which should be named null. This point is wrong. the first parameter on getString should be a key, and should be unique everywhere for the same value.

Another thing is that you are istantiating another istance of SharedPreferences with the same name, so remove the cast in the istantiation.

  @Override
    public View onCreateView( LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
        View view =  inflater.inflate(R.layout.fragment_stream, container, false);
        //playerSettings = getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE); -- they are already istantiated
        streamUrl = playerSettings.getString(/*streamUrl -- replace with a key value*/,"No Link Found");
        //getData();
        Toast.makeText(getActivity(),"Stream Saved"+streamUrl,Toast.LENGTH_LONG).show();
        return view;
    }     

Now you are setting streamUrl to the sharedPreferences's value named with the same variable streamUrl.this means:

streamUrl /*which is currently null*/ = playerSettings.getString(null, "No Link Found");

You should still replace the key from streamUrl to a static unique field.

public void getUrl(String data)
{
    streamUrl=data;
    //playerSettings = this.getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE); -- already done above
    SharedPreferences.Editor editor = playerSettings.edit();
    editor.putString("streamLink", streamUrl);
    //editor.commit(); --replace with apply
    Toast.makeText(getActivity(),"Stream Saved"+streamUrl,Toast.LENGTH_LONG).show();
}

}

This should be the point where you save the value, so the "streamLink" should be the key used above.

Replace commit with apply and remove the istantiation because it's already done

Now.. said that this is how it should look like:

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

public class StreamFragment extends Fragment {

    public String streamUrl=null;
    TextView textView;
    public static final String playerData="pData";
    public static final String valueKey="streamLink";
    SharedPreferences playerSettings;
    public StreamFragment(){};

   @Override
    public void onCreate(Bundle state) {
        super.onCreate(state);
        playerSettings = getActivity().getSharedPreferences(playerData, Context.MODE_PRIVATE);
        streamUrl = playerSettings.getString(valueKey,"No Link Found");
    }

    @Override
    public View onCreateView( LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
        View view =  inflater.inflate(R.layout.fragment_stream, container, false);

        streamUrl = playerSettings.getString(valueKey,"No Link Found");
        //getData();
        Toast.makeText(getActivity(),"Stream Saved"+streamUrl,Toast.LENGTH_LONG).show();
        return view;
    }       

    public void getUrl(String data)
    {
        streamUrl=data;

        SharedPreferences.Editor editor = playerSettings.edit();
        editor.putString(valueKey, streamUrl);
        editor.apply();
        Toast.makeText(getActivity(),"Stream Saved"+streamUrl,Toast.LENGTH_LONG).show();
    }
}

Hope this can help you.

Answer 5

Your getUrl(String) method not called. So your Shared preference value not stored, called it before playerSettings.getString(streamUrl,"No Link Found"); Also you create instance of "SharedPreferences" two times, remove from onCreateView.Use editor.apply() instead of editor.commit().