<string name="current_language">English</string>
<string name="test">test</string>

<resources>
<string name="current_language">English</string>
<string name="test">test</string>
</resources>

<resources>
<string name="current_language">Chinese</string>
<string name="test">测试</string>
</resources>

<TextView
...
text = "@string/userid"
...
/>

public class MainActivity ...
{
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ...
    updateResources(this,"zh");
    ...
  }
}
private static boolean updateResources(Context context, String language) {
    Locale locale = new Locale(language);
    Locale.setDefault(locale);
    Resources resources = context.getResources();
    Configuration configuration = resources.getConfiguration();
    configuration.locale = locale;
    resources.updateConfiguration(configuration, resources.getDisplayMetrics());
    return true;
}