Android preferences set manually are not loaded in settings activity

Question

I want to seed my app's default preferences from a build variable, so I cannot use the XML-based preference defaults.

In my MainActivity , I have this method:

/**
  * Set the default values programmatically
  */
protected void initPreferences() {
    SharedPreferences sharedPref = this.getPreferences(Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPref.edit();
    if (sharedPref.getString("elasticsearch_url", "").equals("")) {
        editor.putString("elasticsearch_url", Env.elasticsearchTestUrl);
    }
    if (sharedPref.getString("elasticsearch_user", "").equals("")) {
        editor.putString("elasticsearch_user", Env.elasticsearchTestUser);
    }
    if (sharedPref.getString("elasticsearch_password", "").equals("")) {
        editor.putString("elasticsearch_password", Env.elasticsearchTestPassword);
    }
    if (sharedPref.getString("elasticsearch_index", "").equals("")) {
        editor.putString("elasticsearch_index", Env.elasticsearchTestIndex);
    }
    editor.commit();
    Log.d(TAG, "Settings: " + sharedPref.getAll());
}

I call this within onCreate directly after the app starts. The log shows the settings being saved fine.

Now, I have a second activity, an automatically-generated SettingsActivity , which looks like this:

package com.aveq.testandroidpacketcapture;

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;

import androidx.annotation.Nullable;
import androidx.appcompat.app.ActionBar;
import androidx.appcompat.app.AppCompatActivity;
import androidx.preference.PreferenceFragmentCompat;

public class SettingsActivity extends AppCompatActivity {
    private static final String TAG = "SettingsActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.settings_activity);
        if (savedInstanceState == null) {
            getSupportFragmentManager()
                    .beginTransaction()
                    .replace(R.id.settings, new SettingsFragment())
                    .commit();
        }
        ActionBar actionBar = getSupportActionBar();
        if (actionBar != null) {
            actionBar.setDisplayHomeAsUpEnabled(false);
        }
    }

    public static class SettingsFragment extends PreferenceFragmentCompat {
        @Override
        public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
            Log.d(TAG, "Setting preferences from XML resource ...");
            setPreferencesFromResource(R.xml.root_preferences, rootKey);
        }
    }
}

Whenever I start this activity via:

Intent intent = new Intent(this, SettingsActivity.class);
startActivityForResult(intent, 0);

the settings activity opens, but the values there are empty:

The XML based on which the preferences are loaded looks like this:

<PreferenceScreen
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <PreferenceCategory
        app:title="Elasticsearch">

        <EditTextPreference
            app:key="elasticsearch_url"
            app:title="Elasticsearch URL"
            app:useSimpleSummaryProvider="true"/>

        <EditTextPreference
            app:key="elasticsearch_user"
            app:title="Elasticsearch username"
            app:useSimpleSummaryProvider="true"/>

        <EditTextPreference
            app:key="elasticsearch_password"
            app:title="Elasticsearch password"
            app:useSimpleSummaryProvider="true"/>

        <EditTextPreference
            app:key="elasticsearch_index"
            app:title="Elasticsearch index"
            app:useSimpleSummaryProvider="true"/>

    </PreferenceCategory>
  </PreferenceScreen>

As far as I can tell, all the keys match up. When I log the shared preferences in the onCreate method of the settings activity, they are correct, so why are my values not loaded?

Answer 1

When using a PreferenceScreen the SharedPreferences get saved to default shared preferences so you need to grab them from there with this

PreferenceManager.getDefaultSharedPreferences(this)

vs pulling them from private context

getPreferences(Context.MODE_PRIVATE)