Android Language Change example Java

Step 1:  Create A New Project and Go to app > res > values > right-click > New > Value Resource File and name it. Select qualifiers as Locale from the available li

st. Follow steps

Step 2:  Now in the string_bn

<resources>
    <string name="app_name">Language Change</string>
<string name="header_text" >"Language Bangla"</string>
</resources>

Step 3:   in the string.xml

<resources>
   <string name="app_name">Language Change</string>
<string name="header_text" >"Language English"</string>
</resources>

Step 4:  XML

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center_horizontal"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="48dp"
        android:text="@string/header_text"
        android:textAlignment="center" />

    <RadioGroup
        android:gravity="center_horizontal"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <RadioButton
            android:id="@+id/btnBangla"
            android:layout_margin="16dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Bangla"/>

        <RadioButton
            android:checked="true"
            android:id="@+id/btnEnglish"
            android:layout_margin="16dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="English"/>
    </RadioGroup>

</LinearLayout>

Step 4:  Create a Java class and name It as LocaleHelper

package com.tutorialb.languagechange;

import android.annotation.TargetApi;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Build;
import android.preference.PreferenceManager;

import java.util.Locale;

public class LocaleHelper {

    private static final String SELECTED_LANGUAGE = "Locale.Helper.Selected.Language";

    public static Context setLocale(Context context, String language) {
        persist(context, language);

        return updateResources(context, language);
    }

    private static void persist(Context context, String language) {
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
        SharedPreferences.Editor editor = preferences.edit();
        editor.putString(SELECTED_LANGUAGE, language);
        editor.apply();
    }


    @TargetApi(Build.VERSION_CODES.N)
    private static Context updateResources(Context context, String language) {
        Locale locale = new Locale(language);
        Locale.setDefault(locale);

        Configuration configuration = context.getResources().getConfiguration();
        configuration.setLocale(locale);
        configuration.setLayoutDirection(locale);

        return context.createConfigurationContext(configuration);
    }

    private static Context updateResourcesLegacy(Context context, String language) {
        Locale locale = new Locale(language);
        Locale.setDefault(locale);

        Resources resources = context.getResources();
        Configuration configuration = resources.getConfiguration();
        configuration.locale = locale;
        configuration.setLayoutDirection(locale);

        resources.updateConfiguration(configuration, resources.getDisplayMetrics());

        return context;
    }

}

Step 4:  MainActivity.java

package com.tutorialb.languagechange;

import android.content.Context;
import android.content.res.Resources;
import android.os.Bundle;
import android.view.View;
import android.widget.RadioButton;
import android.widget.TextView;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity {
    TextView messageView;
    RadioButton btnBangla, btnEnglish;
    Context context;
    Resources resources;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        messageView = findViewById(R.id.textView);
        btnBangla = findViewById(R.id.btnBangla);
        btnEnglish = findViewById(R.id.btnEnglish);

        btnEnglish.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                context = LocaleHelper.setLocale(MainActivity.this, "en");
                resources = context.getResources();
                messageView.setText(resources.getString(R.string.header_text));
            }
        });

        btnBangla.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                context = LocaleHelper.setLocale(MainActivity.this, "bn");
                resources = context.getResources();
                messageView.setText(resources.getString(R.string.header_text));
            }
        });

    }
}

Step 5:  Output