在Android中，可以使用以下代码来下载图像并将其保存在所需位置：

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Environment;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class ImageDownloader extends AsyncTask {

    private String savePath;
    private OnImageDownloadListener listener;

    public interface OnImageDownloadListener {
        void onImageDownloaded(Bitmap bitmap);
        void onImageDownloadError(String error);
    }

    public ImageDownloader(String savePath, OnImageDownloadListener listener) {
        this.savePath = savePath;
        this.listener = listener;
    }

    @Override
    protected Bitmap doInBackground(String... params) {
        String imageUrl = params[0];
        Bitmap bitmap = null;

        try {
            URL url = new URL(imageUrl);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.connect();

            InputStream inputStream = connection.getInputStream();
            bitmap = BitmapFactory.decodeStream(inputStream);

            File dir = new File(savePath);
            if (!dir.exists()) {
                dir.mkdirs();
            }

            File file = new File(dir, "image.jpg");
            FileOutputStream outputStream = new FileOutputStream(file);
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
            outputStream.flush();
            outputStream.close();

        } catch (Exception e) {
            e.printStackTrace();
            listener.onImageDownloadError(e.getMessage());
        }

        return bitmap;
    }

    @Override
    protected void onPostExecute(Bitmap bitmap) {
        if (bitmap != null) {
            listener.onImageDownloaded(bitmap);
        }
    }
}

使用方法如下：

String imageUrl = "https://example.com/image.jpg";
String savePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/MyApp/Images/";

ImageDownloader imageDownloader = new ImageDownloader(savePath, new ImageDownloader.OnImageDownloadListener() {
    @Override
    public void onImageDownloaded(Bitmap bitmap) {
        // 下载成功，可以在这里处理下载后的图像
    }

    @Override
    public void onImageDownloadError(String error) {
        // 下载失败，可以在这里处理错误
    }
});

imageDownloader.execute(imageUrl);

需要注意的是，由于Android 6.0及更高版本的权限限制，下载图像时可能需要动态请求存储权限。在使用此代码之前，请确保已经在AndroidManifest.xml中声明了适当的权限。