我正在尝试将图像从“下载”文件夹加载到imageView，然后使用改造版本将其上传。但是，我得到java.lang.SecurityException: Permission Denial: reading com.android.providers.downloads.DownloadProvider uri content://downloads/all_downloads/124 from pid=24654,uid=10177 requires android.permission.accESS_ALL_DOWNLOADS,or granturiPermission()。我尝试从其他文件夹加载图像，但它们工作正常。我最初收到NullPonterException，发现我必须用 content：// downloads / all_downloads 替换 content：// downloads / public_downloads ，现在我收到了此错误。这是到目前为止我尝试过的代码：

预先感谢

FileUtils.java

public class FileUtils {
    String getPathFromUri(final Context context,final Uri uri) {
        String path = getPathFromLocalUri(context,uri);
        if (path == null) {
            path = getPathFromRemoteUri(context,uri);
        }
        return path;
    }

    @SuppressLint("NewApi")
    public static String getPathFromLocalUri(final Context context,final Uri uri) {
        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        if (isKitKat && DocumentsContract.isDocumenturi(context,uri)) {
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }
            } else if (isDownloadsDocument(uri)) {

                Log.d("isDownload","Yes");
                final String id = DocumentsContract.getDocumentId(uri);

                if (!TextUtils.isEmpty(id)) {
                    try {
                        final Uri contenturi =
                                Contenturis.withAppendedId(
                                        Uri.parse("content://downloads/all_downloads"),Long.valueOf(id));
                        return getDataColumn(context,contenturi,null,null);
                    } catch (NumberFormatException e) {
                        return null;
                    }
                }

            } else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                Uri contenturi = null;
                if ("image".equals(type)) {
                    contenturi = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contenturi = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contenturi = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }

                final String selection = "_id=?";
                final String[] selectionArgs = new String[] {split[1]};

                return getDataColumn(context,selection,selectionArgs);
            }
        } else if ("content".equalsIgnoreCase(uri.getScheme())) {

            // Return the remote address
            if (isGooglePhotosUri(uri)) {
                return uri.getLastPathSegment();
            }

            return getDataColumn(context,uri,null);
        } else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }

        return null;
    }

    private static String getDataColumn(
            Context context,Uri uri,String selection,String[] selectionArgs) {
        Cursor cursor = null;

        final String column = "_data";
        final String[] projection = {column};

        try {
            cursor = context.getcontentResolver().query(uri,projection,selectionArgs,null);
            if (cursor != null && cursor.moveToFirst()) {
                final int column_index = cursor.getcolumnIndexOrThrow(column);
                return cursor.getString(column_index);
            }
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
        return null;
    }

    private static String getPathFromRemoteUri(final Context context,final Uri uri) {
        // The code below is why Java now has try-with-resources and the Files utility.
        File file = null;
        InputStream inputStream = null;
        OutputStream outputStream = null;
        boolean success = false;
        try {
            inputStream = context.getcontentResolver().openInputStream(uri);
            file = File.createTempFile("image_picker","jpg",context.getcacheDir());
            outputStream = new FileOutputStream(file);
            if (inputStream != null) {
                copy(inputStream,outputStream);
                success = true;
            }
        } catch (IOException ignored) {
        } finally {
            try {
                if (inputStream != null) inputStream.close();
            } catch (IOException ignored) {
            }
            try {
                if (outputStream != null) outputStream.close();
            } catch (IOException ignored) {
                // If closing the output stream fails,we cannot be sure that the
                // target file was written in full. Flushing the stream merely moves
                // the bytes into the OS,not necessarily to the file.
                success = false;
            }
        }
        return success ? file.getPath() : null;
    }

    private static void copy(InputStream in,OutputStream out) throws IOException {
        final byte[] buffer = new byte[4 * 1024];
        int bytesRead;
        while ((bytesRead = in.read(buffer)) != -1) {
            out.write(buffer,bytesRead);
        }
        out.flush();
    }

    private static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getauthority());
    }

    private static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getauthority());
    }

    private static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getauthority());
    }

    private static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getauthority());
    }
}

pickImage方法：

 //Gallery
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    public void openGallery() {

        if (ContextCompat.checkSelfPermission(this,Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            activityCompat.requestPermissions(this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},READ_STORAGE_PERMISSION);
        } else {
            Intent intent = new Intent(Intent.actION_OPEN_DOCUMENT);
            intent.setflags(Intent.flaG_GRANT_READ_URI_PERMISSION);
            intent.setType("image/*");
            startactivityForResult(intent,GALLERY_CODE);
        }

    }

清单：

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:requestLegacyExternalStorage="true"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsrtl="true"
        android:theme="@style/Apptheme"
        android:usesCleartextTraffic="true">
.......

 <provider
            android:name="androidx.core.content.FileProvider"
            android:authorities="${applicationid}"
            android:exported="false"
            android:granturiPermissions="true"
            tools:replace="android:authorities">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/provider_paths"
                tools:replace="android:resource" />
        </provider>

</application>

provider_paths.xml

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <external-path
        name="external"
        path="." />
    <external-files-path
        name="external_files"
        path="." />
    <cache-path
        name="cache"
        path="." />
    <external-cache-path
        name="external_cache"
        path="." />
    <files-path
        name="files"
        path="." />
</paths>