// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.base;
import android.content.ContentResolver;
import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.text.TextUtils;
import android.webkit.MimeTypeMap;
import androidx.annotation.Nullable;
import org.jni_zero.CalledByNative;
import java.io.IOException;
/** This class provides methods to access content URI schemes. */
public abstract class ContentUriUtils {
private static final String TAG = "ContentUriUtils";
// Prevent instantiation.
private ContentUriUtils() {}
/**
* Opens the content URI for the specified mode, and returns the file descriptor to the caller.
* The caller is responsible for closing the file descriptor.
*
* @param uriString the content URI to open
* @param mode the mode to open. Allows all values from ParcelFileDescriptor#parseMode(): ("r",
* "w", "wt", "wa", "rw" or "rwt"), but disallows "w" which has been the source of android
* security issues.
* @return file descriptor upon success, or -1 otherwise.
*/
@CalledByNative
public static int openContentUri(String uriString, String mode) {
AssetFileDescriptor afd = getAssetFileDescriptor(uriString, mode);
if (afd != null) {
return afd.getParcelFileDescriptor().detachFd();
}
return -1;
}
/**
* Check whether a content URI exists.
*
* @param uriString the content URI to query.
* @return true if the URI exists, or false otherwise.
*/
@CalledByNative
public static boolean contentUriExists(String uriString) {
AssetFileDescriptor asf = null;
try {
asf = getAssetFileDescriptor(uriString, "r");
return asf != null;
} finally {
// Do not use StreamUtil.closeQuietly here, as AssetFileDescriptor
// does not implement Closeable until KitKat.
if (asf != null) {
try {
asf.close();
} catch (IOException e) {
// Closing quietly.
}
}
}
}
/**
* Get the file size of a content URI.
*
* @param uriString the content URI to look up.
* @return File size or -1 if the file does not exist.
*/
@CalledByNative
public static long getContentUriFileSize(String uriString) {
long size = -1;
AssetFileDescriptor afd = getAssetFileDescriptor(uriString, "r");
if (afd != null) {
size = afd.getLength();
}
StreamUtil.closeQuietly(afd);
return size;
}
/**
* Retrieve the MIME type for the content URI.
*
* @param uriString the content URI to look up.
* @return MIME type or null if the input params are empty or invalid.
*/
@CalledByNative
public static String getMimeType(String uriString) {
ContentResolver resolver = ContextUtils.getApplicationContext().getContentResolver();
Uri uri = Uri.parse(uriString);
if (isVirtualDocument(uri)) {
String[] streamTypes = resolver.getStreamTypes(uri, "*/*");
return (streamTypes != null && streamTypes.length > 0) ? streamTypes[0] : null;
}
return resolver.getType(uri);
}
/**
* Helper method to open a content URI and returns the ParcelFileDescriptor.
*
* @param uriString the content URI to open.
* @param mode the mode to open. Allows all values from ParcelFileDescriptor#parseMode(): ("r",
* "w", "wt", "wa", "rw" or "rwt"), but disallows "w" which has been the source of android
* security issues.
* @return AssetFileDescriptor of the content URI, or NULL if the file does not exist.
*/
private static AssetFileDescriptor getAssetFileDescriptor(String uriString, String mode) {
if ("w".equals(mode)) {
Log.e(TAG, "Cannot open files with mode 'w'");
return null;
}
ContentResolver resolver = ContextUtils.getApplicationContext().getContentResolver();
Uri uri = Uri.parse(uriString);
try {
AssetFileDescriptor afd = null;
if (isVirtualDocument(uri)) {
String[] streamTypes = resolver.getStreamTypes(uri, "*/*");
if (streamTypes != null && streamTypes.length > 0) {
afd = resolver.openTypedAssetFileDescriptor(uri, streamTypes[0], null);
}
} else {
afd = resolver.openAssetFileDescriptor(uri, mode);
}
if (afd != null && afd.getStartOffset() != 0) {
StreamUtil.closeQuietly(afd);
throw new SecurityException("Cannot open files with non-zero offset type.");
}
return afd;
} catch (Exception e) {
Log.w(TAG, "Cannot open content uri: %s", uriString, e);
}
return null;
}
/**
* Method to resolve the display name of a content URI.
*
* @param uri the content URI to be resolved.
* @param context {@link Context} in interest.
* @param columnField the column field to query.
* @return the display name of the @code uri if present in the database
* or an empty string otherwise.
*/
public static String getDisplayName(Uri uri, Context context, String columnField) {
if (uri == null) return "";
ContentResolver contentResolver = context.getContentResolver();
try (Cursor cursor = contentResolver.query(uri, null, null, null, null)) {
if (cursor != null && cursor.getCount() >= 1) {
cursor.moveToFirst();
int displayNameIndex = cursor.getColumnIndex(columnField);
if (displayNameIndex == -1) {
return "";
}
String displayName = cursor.getString(displayNameIndex);
// For Virtual documents, try to modify the file extension so it's compatible
// with the alternative MIME type.
if (hasVirtualFlag(cursor)) {
String[] mimeTypes = contentResolver.getStreamTypes(uri, "*/*");
if (mimeTypes != null && mimeTypes.length > 0) {
String ext =
MimeTypeMap.getSingleton().getExtensionFromMimeType(mimeTypes[0]);
if (ext != null) {
// Just append, it's simpler and more secure than altering an
// existing extension.
displayName += "." + ext;
}
}
}
return displayName;
}
} catch (NullPointerException e) {
// Some android models don't handle the provider call correctly.
// see crbug.com/345393
return "";
}
return "";
}
/**
* Method to resolve the display name of a content URI if possible.
*
* @param uriString the content URI to look up.
* @return the display name of the uri if present in the database or null otherwise.
*/
@Nullable
@CalledByNative
public static String maybeGetDisplayName(String uriString) {
Uri uri = Uri.parse(uriString);
try {
String displayName =
getDisplayName(
uri,
ContextUtils.getApplicationContext(),
MediaStore.MediaColumns.DISPLAY_NAME);
return TextUtils.isEmpty(displayName) ? null : displayName;
} catch (Exception e) {
// There are a few Exceptions we can hit here (e.g. SecurityException), but we don't
// particularly care what kind of Exception we hit. If we hit one, just don't return a
// display name.
Log.w(TAG, "Cannot open content uri: %s", uriString, e);
}
// If we are unable to query the content URI, just return null.
return null;
}
/**
* Checks whether the passed Uri represents a virtual document.
*
* @param uri the content URI to be resolved.
* @return True for virtual file, false for any other file.
*/
private static boolean isVirtualDocument(Uri uri) {
if (uri == null) return false;
if (!DocumentsContract.isDocumentUri(ContextUtils.getApplicationContext(), uri)) {
return false;
}
ContentResolver contentResolver = ContextUtils.getApplicationContext().getContentResolver();
try (Cursor cursor = contentResolver.query(uri, null, null, null, null)) {
if (cursor != null && cursor.getCount() >= 1) {
cursor.moveToFirst();
return hasVirtualFlag(cursor);
}
} catch (NullPointerException e) {
// Some android models don't handle the provider call correctly.
// see crbug.com/345393
return false;
}
return false;
}
/**
* Checks whether the passed cursor for a document has a virtual document flag.
*
* The called must close the passed cursor.
*
* @param cursor Cursor with COLUMN_FLAGS.
* @return True for virtual file, false for any other file.
*/
private static boolean hasVirtualFlag(Cursor cursor) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) return false;
int index = cursor.getColumnIndex(DocumentsContract.Document.COLUMN_FLAGS);
return index > -1
&& (cursor.getLong(index) & DocumentsContract.Document.FLAG_VIRTUAL_DOCUMENT) != 0;
}
/**
* @return whether a Uri has content scheme.
*/
public static boolean isContentUri(String uri) {
if (uri == null) return false;
Uri parsedUri = Uri.parse(uri);
return parsedUri != null && ContentResolver.SCHEME_CONTENT.equals(parsedUri.getScheme());
}
/**
* Deletes a content uri from the system.
*
* @return True if the uri was deleted.
*/
@CalledByNative
public static boolean delete(String uriString) {
assert isContentUri(uriString);
Uri parsedUri = Uri.parse(uriString);
ContentResolver resolver = ContextUtils.getApplicationContext().getContentResolver();
return resolver.delete(parsedUri, null, null) > 0;
}
}
Codebase Browser
chromium