src/base/android/java/src/org/chromium/base/ContentUriUtils.java - cobalt - Git at Google

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // 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.os.ParcelFileDescriptor;
 import android.provider.DocumentsContract;
 import android.provider.MediaStore;
 import android.support.annotation.Nullable;
 import android.text.TextUtils;
 import android.util.Log;
 import android.webkit.MimeTypeMap;

 import org.chromium.base.annotations.CalledByNative;

 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;

 /**
  * This class provides methods to access content URI schemes.
  */
 public abstract class ContentUriUtils {
     private static final String TAG = "ContentUriUtils";
     private static FileProviderUtil sFileProviderUtil;

     // Guards access to sFileProviderUtil.
     private static final Object sLock = new Object();

     /**
      * Provides functionality to translate a file into a content URI for use
      * with a content provider.
      */
     public interface FileProviderUtil {
         /**
          * Generate a content URI from the given file.
          *
          * @param file The file to be translated.
          */
         Uri getContentUriFromFile(File file);
     }

     // Prevent instantiation.
     private ContentUriUtils() {}

     public static void setFileProviderUtil(FileProviderUtil util) {
         synchronized (sLock) {
             sFileProviderUtil = util;
         }
     }

     public static Uri getContentUriFromFile(File file) {
         synchronized (sLock) {
             if (sFileProviderUtil != null) {
                 return sFileProviderUtil.getContentUriFromFile(file);
             }
         }
         return null;
     }

     /**
      * Opens the content URI for reading, and returns the file descriptor to
      * the caller. The caller is responsible for closing the file descriptor.
      *
      * @param uriString the content URI to open
      * @return file descriptor upon success, or -1 otherwise.
      */
     @CalledByNative
     public static int openContentUriForRead(String uriString) {
         AssetFileDescriptor afd = getAssetFileDescriptor(uriString);
         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);
             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.
                 }
             }
         }
     }

     /**
      * 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.
      * @return AssetFileDescriptor of the content URI, or NULL if the file does not exist.
      */
     private static AssetFileDescriptor getAssetFileDescriptor(String uriString) {
         ContentResolver resolver = ContextUtils.getApplicationContext().getContentResolver();
         Uri uri = Uri.parse(uriString);

         try {
             if (isVirtualDocument(uri)) {
                 String[] streamTypes = resolver.getStreamTypes(uri, "*/*");
                 if (streamTypes != null && streamTypes.length > 0) {
                     AssetFileDescriptor afd =
                             resolver.openTypedAssetFileDescriptor(uri, streamTypes[0], null);
                     if (afd != null && afd.getStartOffset() != 0) {
                         // Do not use StreamUtil.closeQuietly here, as AssetFileDescriptor
                         // does not implement Closeable until KitKat.
                         try {
                             afd.close();
                         } catch (IOException e) {
                             // Closing quietly.
                         }
                         throw new SecurityException("Cannot open files with non-zero offset type.");
                     }
                     return afd;
                 }
             } else {
                 ParcelFileDescriptor pfd = resolver.openFileDescriptor(uri, "r");
                 if (pfd != null) {
                     return new AssetFileDescriptor(pfd, 0, AssetFileDescriptor.UNKNOWN_LENGTH);
                 }
             }
         } catch (FileNotFoundException e) {
             Log.w(TAG, "Cannot find content uri: " + uriString, e);
         } catch (SecurityException e) {
             Log.w(TAG, "Cannot open content uri: " + uriString, e);
         } catch (Exception e) {
             Log.w(TAG, "Unknown content uri: " + 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: " + 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 (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) return false;
         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;
     }
 }
	// Copyright 2013 The Chromium Authors. All rights reserved.
	// 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.os.ParcelFileDescriptor;
	import android.provider.DocumentsContract;
	import android.provider.MediaStore;
	import android.support.annotation.Nullable;
	import android.text.TextUtils;
	import android.util.Log;
	import android.webkit.MimeTypeMap;

	import org.chromium.base.annotations.CalledByNative;

	import java.io.File;
	import java.io.FileNotFoundException;
	import java.io.IOException;

	/**
	* This class provides methods to access content URI schemes.
	*/
	public abstract class ContentUriUtils {
	private static final String TAG = "ContentUriUtils";
	private static FileProviderUtil sFileProviderUtil;

	// Guards access to sFileProviderUtil.
	private static final Object sLock = new Object();

	/**
	* Provides functionality to translate a file into a content URI for use
	* with a content provider.
	*/
	public interface FileProviderUtil {
	/**
	* Generate a content URI from the given file.
	*
	* @param file The file to be translated.
	*/
	Uri getContentUriFromFile(File file);
	}

	// Prevent instantiation.
	private ContentUriUtils() {}

	public static void setFileProviderUtil(FileProviderUtil util) {
	synchronized (sLock) {
	sFileProviderUtil = util;
	}
	}

	public static Uri getContentUriFromFile(File file) {
	synchronized (sLock) {
	if (sFileProviderUtil != null) {
	return sFileProviderUtil.getContentUriFromFile(file);
	}
	}
	return null;
	}

	/**
	* Opens the content URI for reading, and returns the file descriptor to
	* the caller. The caller is responsible for closing the file descriptor.
	*
	* @param uriString the content URI to open
	* @return file descriptor upon success, or -1 otherwise.
	*/
	@CalledByNative
	public static int openContentUriForRead(String uriString) {
	AssetFileDescriptor afd = getAssetFileDescriptor(uriString);
	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);
	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.
	}
	}
	}
	}

	/**
	* 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.
	* @return AssetFileDescriptor of the content URI, or NULL if the file does not exist.
	*/
	private static AssetFileDescriptor getAssetFileDescriptor(String uriString) {
	ContentResolver resolver = ContextUtils.getApplicationContext().getContentResolver();
	Uri uri = Uri.parse(uriString);

	try {
	if (isVirtualDocument(uri)) {
	String[] streamTypes = resolver.getStreamTypes(uri, "/");
	if (streamTypes != null && streamTypes.length > 0) {
	AssetFileDescriptor afd =
	resolver.openTypedAssetFileDescriptor(uri, streamTypes[0], null);
	if (afd != null && afd.getStartOffset() != 0) {
	// Do not use StreamUtil.closeQuietly here, as AssetFileDescriptor
	// does not implement Closeable until KitKat.
	try {
	afd.close();
	} catch (IOException e) {
	// Closing quietly.
	}
	throw new SecurityException("Cannot open files with non-zero offset type.");
	}
	return afd;
	}
	} else {
	ParcelFileDescriptor pfd = resolver.openFileDescriptor(uri, "r");
	if (pfd != null) {
	return new AssetFileDescriptor(pfd, 0, AssetFileDescriptor.UNKNOWN_LENGTH);
	}
	}
	} catch (FileNotFoundException e) {
	Log.w(TAG, "Cannot find content uri: " + uriString, e);
	} catch (SecurityException e) {
	Log.w(TAG, "Cannot open content uri: " + uriString, e);
	} catch (Exception e) {
	Log.w(TAG, "Unknown content uri: " + 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: " + 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 (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) return false;
	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;
	}
	}