how to get android device id ? l dont know whats the "context" , lam fresh, please help me

import android.content.Context; import android.provider.Settings;

public class getDeviceID {

public void getAndroidID(Context context) {
    String android_id= Settings.System.getString(context.getContentResolver(),
            Settings.Secure.ANDROID_ID);

    System.out.println(android_id);
}

}