androidのdialog点击按钮不关闭

AlertDialog.Builder builder = new AlertDialog.Builder(context);
            AlertDialog alertDialog = builder.setPositiveButton("保存", null)
                    .setNegativeButton("收藏", (dialog, which) -> {
                        ToastUtils.shortToast("我还没做收藏功能!");
                    }).create();
            alertDialog.show();
            alertDialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener(v1 -> {
                RestVolleyDownload.DownloadResponse response = RestVolleyDownload.syncDownload(context, url, url.substring(url.lastIndexOf("/") + 1));
                System.out.println(response);
                ToastUtils.shortToast("保存成功");
            });