具有Kotlin委托属性的Java首选项API

public interface PreferenceDelegate {
    String getString(String key, String defaultValue);
    void setString(String key, String value);
}

public class SharedPreferencesDelegate implements PreferenceDelegate {
    private SharedPreferences preferences;

    public SharedPreferencesDelegate(Context context) {
        preferences = PreferenceManager.getDefaultSharedPreferences(context);
    }

    @Override
    public String getString(String key, String defaultValue) {
        return preferences.getString(key, defaultValue);
    }

    @Override
    public void setString(String key, String value) {
        preferences.edit().putString(key, value).apply();
    }
}

public class MyClass {
    private PreferenceDelegate preferenceDelegate;

    public MyClass(Context context) {
        preferenceDelegate = new SharedPreferencesDelegate(context);
    }

    public String getMyPreference() {
        return preferenceDelegate.getString("my_preference", "default_value");
    }

    public void setMyPreference(String value) {
        preferenceDelegate.setString("my_preference", value);
    }
}