[Android] intent put, get

Intent go_order = new Intent(getApplication().getApplicationContext(), OrderActivity.class);
go_order.putExtra("productNum", productNum);
startActivity(go_order);

Intent go_live_play = new Intent(context.getApplicationContext(), ViewerActivity.class);
go_live_play.putExtra("productNum", item.getProduct_num());
context.startActivity(go_live_play.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK));

productNum = getIntent().getStringExtra("productNum");