我无法将文件下载到内存中

Question

如果图像的大小较小（例如100或200kb），则会下载该图像，但是如果图像的大小较大（如以MB为单位），则会显示已下载的消息，但内存中没有文件。

我的代码如下。

告诉我下面给出的代码中的错误

public static void setBgOrDownload(final String urlString, final Activity activity, final boolean download) {

    Picasso.get().load(urlString).into(new Target() {
        @Override
        public void onBitmapLoaded(final Bitmap bitmap, Picasso.LoadedFrom from) {
            if (download) {
               saveImageBitmap(activity, urlString,bitmap);

            } else {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        WallpaperManager wallpaperManager = WallpaperManager.getInstance(activity);
                        try {
                            wallpaperManager.setBitmap(bitmap);
                            ((PreviewActivity) activity).wallpaperSet(true);
                        } catch (IOException e) {
                            e.printStackTrace();
                            ((PreviewActivity) activity).wallpaperSet(true);

                        }
                    }
                }).start();

            }

另一个代码

 public static void saveImageBitmap(Activity context, String url, Bitmap bitmap) {
    final AtomicBoolean isFilePresent = new AtomicBoolean(false);
    String myDir = Environment.getExternalStorageDirectory().toString() + "/" + context.getResources().getString(R.string.app_name);
    File fileDir = new File(myDir);

    if (!fileDir.exists()) {
        fileDir.mkdirs();
    }
    url = url.substring(url.lastIndexOf("/") + 1);
    final File newFile = new File(myDir, "Wallpaper_" + url);
    File[] filesList = fileDir.listFiles();
    if (filesList != null) {

        ArrayList<File> files = new ArrayList<>(Arrays.asList(filesList));
        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) {
            Optional<File> result = files.stream().filter(new Predicate<File>() {
                @Override
                public boolean test(File file) {
                    return file.getAbsolutePath().equals(newFile.getAbsolutePath());
                }
            }).findFirst();
            result.ifPresent(new Consumer<File>() {
                @Override
                public void accept(File file) {
                    isFilePresent.set(true);
                }
            });
        } else {
            for (File file : files) {
                if (file.getAbsolutePath().equals(newFile.getAbsolutePath())) {
                    isFilePresent.set(true);
                    break;
                }