从 Android 保存图像文件

Question

我正在尝试从 Android 保存图像文件，但出现错误。我已经为清单添加了读写权限。我正在尝试以这种方式保存图像文件（文件路径类似于“content://media/external/images/media/12”）：

File source = new File(filePath);
blob.upload(new FileInputStream(source), source.length());

我得到的错误：

04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err: java.io.FileNotFoundException: content:/media/external/images/media/12: open failed: ENOENT (No such file or directory)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:452)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at java.io.FileInputStream.<init>(FileInputStream.java:76)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at com.example.gaya.searchpeople.PhotoInfoActivity$NetworkConnector.doInBackground(PhotoInfoActivity.java:103)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at com.example.gaya.searchpeople.PhotoInfoActivity$NetworkConnector.doInBackground(PhotoInfoActivity.java:75)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at android.os.AsyncTask$2.call(AsyncTask.java:295)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at java.util.concurrent.FutureTask.run(FutureTask.java:237)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at java.lang.Thread.run(Thread.java:818)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err: Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at libcore.io.Posix.open(Native Method)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:438)
04-13 09:27:05.453 6947-7534/com.example.gaya.searchpeople W/System.err:    ... 9 more

Answer 1

这不是文件路径。您已获取Uri，将其转换为String，并尝试将其用作文件路径。这行不通。

相反，请在ContentResolver 上调用openInputStream() 以获取关于您的Uri 标识的内容的InputStream。

Answer 2

尝试使用它，它对我有用，可以从 URI 获取绝对文件路径

public static String getAbsolutePath(final Context context, final Uri uri) {

final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
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];
    }

    // TODO handle non-primary volumes
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {

    final String id = DocumentsContract.getDocumentId(uri);
    final Uri contentUri = ContentUris.withAppendedId(
            Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

    return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
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, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {

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

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

 return null;
}


 public 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, selection, 
 selectionArgs,null);
  if (cursor != null && cursor.moveToFirst()) {
    final int index = cursor.getColumnIndexOrThrow(column);
    return cursor.getString(index);
}
} finally {
if (cursor != null)
    cursor.close();
}
 return null;
}

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

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


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

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