Question

在Android Studio中，我收到两个不同的错误，第一个：“找不到项目”，然后：“拒绝访问”。下载后打开文件时会发生这种情况。我有以下权限：

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

正在下载文件，但我无法阅读它们。以下是我的代码：

//first error by this way
//String PATH = "/data/data/com.myproj.myproj/attafiles/";
//File folder = new File(PATH);
//            if (!folder.exists()) {
//                folder.mkdirs();
//            }
//URL url = new URL(imageURL);
//File file = new File(folder , fileName);

//Second error
URL url = new URL(imageURL);
File file = new File(context.getFilesDir(), fileName);

URLConnection ucon = url.openConnection();

InputStream is = ucon.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);


ByteArrayBuffer baf = new ByteArrayBuffer(50);
int current = 0;
while ((current = bis.read()) != -1) {
      baf.append((byte) current);
}

FileOutputStream fos = new FileOutputStream(file);
fos.write(baf.toByteArray());fos.close();
Uri path = Uri.fromFile(file);
String fileExtension= MimeTypeMap.getFileExtensionFromUrl(path.toString());
String mimeType= MimeTypeMap.getSingleton().getMimeTypeFromExtension(fileExtension);
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(path, mimeType);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);

Answer 1

首先检查您的清单中是否同时具有以下权限：

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

如果您已经同时使用它们，请在下载后尝试刷新文件路径。将此方法添加到您的类或Util包中：

public static void updateFile(Context context, String Newpath) {
    context.sendBroadcast(new Intent(
            Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri
            .parse("file://" + Newpath)));
    Log.v(TAG, "[updateGallery] Updating gallery");
}

换句话说，尝试使用下一个方法来读取您的文件：

private String readFromFile() {

String ret = "";

try {
    InputStream inputStream = openFileInput("fileURL");

    if ( inputStream != null ) {
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
        String receiveString = "";
        StringBuilder stringBuilder = new StringBuilder();

        while ( (receiveString = bufferedReader.readLine()) != null ) {
            stringBuilder.append(receiveString);
        }

        inputStream.close();
        ret = stringBuilder.toString();
    }
}
catch (FileNotFoundException e) {
    Log.e("login activity", "File not found: " + e.toString());
} catch (IOException e) {
    Log.e("login activity", "Can not read file: " + e.toString());
}

return ret;

}

希望它会对你有所帮助。祝你好运！

Android Studio，无法找到项目，下载后打开文件时

1 个答案: