Question

我正在通过网络服务提供的网址从服务器下载文件。我对每个版本的设备都很成功，但在OS 4.1设备中却出现异常。我使用下面的代码：

public static Boolean DownloadFile(String fileURL, File directory) {
                try {

                        FileOutputStream f = new FileOutputStream(directory);
                        URL u = new URL(fileURL);
                        HttpURLConnection c = (HttpURLConnection) u.openConnection();
                        c.setRequestMethod("GET");
                        c.setDoOutput(true);
                        c.connect();

                        InputStream in = c.getInputStream();

                        byte[] buffer = new byte[1024];
                        int len1 = 0;
                        while ((len1 = in.read(buffer)) > 0) {
                                f.write(buffer, 0, len1);
                        }
                        f.close();
                        return true;
                } catch (Exception e) {
                        e.printStackTrace();
                        return false;
                }
        }

我在 c.getInputStream（）; 行获得java.io.FileNotFoundException 请建议我解决这个问题。

我打算使用内部存储器，但由于用户无法访问内部存储器。

Answer 1

试试这段代码：请注意，创建文件的CONTEXT可以是Activity / ApplicationContext / etc

public boolean downloadFile(final String path)
    {
        try
        {
            URL url = new URL(path);

            URLConnection ucon = url.openConnection();
            ucon.setReadTimeout(5000);
            ucon.setConnectTimeout(10000);

            InputStream is = ucon.getInputStream();
            BufferedInputStream inStream = new BufferedInputStream(is, 1024 * 5);

            File file = new File(CONTEXT.getDir("filesdir", Context.MODE_PRIVATE) + "/yourfile.png");

            if (file.exists())
            {
                file.delete();
            }
            file.createNewFile();

            FileOutputStream outStream = new FileOutputStream(file);
            byte[] buff = new byte[5 * 1024];

            int len;
            while ((len = inStream.read(buff)) != -1)
            {
                outStream.write(buff, 0, len);
            }

            outStream.flush();
            outStream.close();
            inStream.close();

        }
        catch (Exception e)
        {
            e.printStackTrace();
            return false;
        }

        return true;
    }

Answer 2

试试这段代码：

  String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/saved_images");    
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-"+ n +".jpg";
File file = new File (myDir, fname);
if (file.exists ()) file.delete (); 
try {
       FileOutputStream out = new FileOutputStream(file);
       finalBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
       out.flush();
       out.close();

} catch (Exception e) {
       e.printStackTrace();
}

并添加清单：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

将文件保存到android的内部存储器？

2 个答案: