Develop Reference

Blob Storage infrastructure IBlobContainer relies on deprecated mechanism. How should I fix this?

I am implementing the BLOB Storing capability provided through the Volo.Abp.BlobStoring.IBlobContainer interface.
I believe I have everything coded and configured correctly but a recent deprecation by Microsoft has me wondering if there is a better implementation than what I am attempting.
Here is my code:
public async Task StorePhotoAsync(Photo photo)
{
var photoBytes = ObjectToByteArray(photo);
await _blobContainer.SaveAsync(photo.Id.ToString(), photoBytes);
}
// TODO - Reimplement (deprecated serialization) - JLavallet 2022-03-09 10:41
private byte[] ObjectToByteArray(object obj)
{
if (obj == null)
{
return null;
}
var bf = new BinaryFormatter();
using var ms = new MemoryStream();
bf.Serialize(ms, obj);
return ms.ToArray();
}
// TODO - Reimplement (deprecated serialization) - JLavallet 2022-03-09 10:41
private object ByteArrayToObject(byte[] arrBytes)
{
using var memStream = new MemoryStream();
var binForm = new BinaryFormatter();
memStream.Write(arrBytes, 0, arrBytes.Length);
memStream.Seek(0, SeekOrigin.Begin);
var obj = binForm.Deserialize(memStream);
return obj;
}
As you can see from my to do comments and the screenshot below, there is a deprecation of the Serialize and Deserialize methods of the BinaryFormatter:
Could anyone suggest an alternative approach? The IBlobContainer only wants to save a byte array.

So after Mr. T set me straight, I read the documentation for JSON UTF8 serialization and deserialization, and here's what I came up with:
public async Task StorePhotoCacheItemAsync(PhotoCacheItem photoCacheItem)
{
var bytes = PhotoCacheItemToByteArray(photoCacheItem);
await _blobContainer.SaveAsync(photoCacheItem.Id.ToString(), bytes);
}
private byte[] PhotoCacheItemToByteArray(PhotoCacheItem photoCacheItem)
{
if (photoCacheItem == null)
{
return null;
}
// the old way
//var bf = new BinaryFormatter();
//using var ms = new MemoryStream();
//bf.Serialize(ms, obj);
// a new way
//using var ms = new MemoryStream();
//using var writer = new Utf8JsonWriter(ms);
//JsonSerializer.Serialize(writer, photoCacheItem);
//return ms.ToArray();
// a better new way
var bytes = JsonSerializer.SerializeToUtf8Bytes(photoCacheItem);
return bytes;
}
private async Task<PhotoCacheItem> GetPhotoCacheItemFromBlobStorage(Guid photoId)
{
var bytes = await _blobContainer.GetAllBytesOrNullAsync(photoId.ToString());
if (bytes == null)
{
return null;
}
var photoCacheItem = ByteArrayToPhotoCacheItem(bytes);
return photoCacheItem;
}
private PhotoCacheItem ByteArrayToPhotoCacheItem(byte[] bytes)
{
// the old way
//using var ms = new MemoryStream();
//var bf = new BinaryFormatter();
//ms.Write(bytes, 0, bytes.Length);
//ms.Seek(0, SeekOrigin.Begin);
//var obj = bf.Deserialize(ms);
// a new way
//var utf8Reader = new Utf8JsonReader(bytes);
//var photoCacheItem = JsonSerializer.Deserialize<PhotoCacheItem>(ref utf8Reader)!;
// a better new way
var readOnlySpan = new ReadOnlySpan<byte>(bytes);
var photoCacheItem = JsonSerializer.Deserialize<PhotoCacheItem>(readOnlySpan)!;
return photoCacheItem;
}

Reading serialized objects from binary file

I'm trying to write and read serialized objects to a binary file. I'm using Append FileMode to add serialized objects but when i try to read the file, it only print a single deserialized object.
Here's my serialization method.
public void serialize(){
MyObject obj = new MyObject();
obj.n1 = 1;
obj.n2 = 24;
obj.str = "Some String";
IFormatter formatter = new BinaryFormatter();
Stream stream = new FileStream("MyFile.bin", FileMode.Append, FileAccess.Write, FileShare.None);
formatter.Serialize(stream, obj);
stream.Close()
}
Here's my deserialization method.
public static void read()
{
IFormatter formatter = new BinaryFormatter();
Stream stream = new FileStream("MyFile.bin", FileMode.Open, FileAccess.Read, FileShare.Read);
MyObject obj = (MyObject)formatter.Deserialize(stream);
stream.Close();
// Here's the proof.
Console.WriteLine("n1: {0}", obj.n1);
Console.WriteLine("n2: {0}", obj.n2);
Console.WriteLine("str: {0}", obj.str);
}
How can we loop through every single serialized record in file, like we use File.eof() or while(file.read()) in C++.

Deserialize only returns one object. You need to create a collection and loop until the end of the stream is reached:
List<MyObject> list = new List<MyObject>();
Stream stream = new FileStream("MyFile.bin", FileMode.Open, FileAccess.Read, FileShare.Read);
while(stream.Position < stream.Length)
{
MyObject obj = (MyObject)formatter.Deserialize(stream);
list.add(obj);
}

The explanation above is correct, however I'd put it like this, using a collection of your like:
public static void serializeIt()
{
MyObject obj = new MyObject();
obj.n1 = 1;
obj.n2 = 24;
obj.str = "Some String";
MyObject obj2 = new MyObject();
obj2.n1 = 1;
obj2.n2 = 24;
obj2.str = "Some other String";
List<MyObject> list = new List<MyObject>();
list.Add(obj);
list.Add(obj2);
IFormatter formatter = new BinaryFormatter();
Stream stream = new FileStream("MyFile.bin", FileMode.Append,FileAccess.Write, FileShare.None);
formatter.Serialize(stream, list);
stream.Close();
}
public static void read()
{
IFormatter formatter = new BinaryFormatter();
Stream stream = new FileStream("MyFile.bin", FileMode.Open, FileAccess.Read, FileShare.Read);
List<MyObject> list = (List<MyObject>)formatter.Deserialize(stream);
stream.Close();
}
You should also make sure that the MyFile.bin is rewriten each time you serialize your collection, as it would always return the collection that was saved first if you'd keep appending them. That should be the only downside.

Thank you for your help, I made this.
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
private static Dictionary<int, ArrayList> J1_CarteDeck;
private static string PathDocuments = String.Format("{0}\\Antize Game\\", Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments));
private const string FILE_NAME = "Antize.data";
public static bool SauvegarderDeck()
{
if (!(Directory.Exists(PathDocuments)))
Directory.CreateDirectory(PathDocuments);
if (File.Exists(PathDocuments + FILE_Deck))
File.Delete(PathDocuments + FILE_Deck);
foreach (ArrayList child in J1_CarteDeck.Values)
{
if(child != null)
{
BinaryFormatter formatter = new BinaryFormatter();
FileStream stream = new FileStream(PathDocuments + FILE_Deck, FileMode.Append, FileAccess.Write, FileShare.None);
formatter.Serialize(stream, child);
stream.Close();
}
}
if (File.Exists(PathDocuments + FILE_Deck))
return true;
else
return false;
}
public static bool ChargerDeck()
{
if (!(File.Exists(PathDocuments + FILE_Deck)))
return false;
int cptr = 1;
J1_CarteDeck = new Dictionary<int, ArrayList>();
BinaryFormatter formatter = new BinaryFormatter();
Stream stream = new FileStream(PathDocuments + FILE_Deck, FileMode.Open, FileAccess.Read, FileShare.None);
while (stream.Position < stream.Length)
{
J1_CarteDeck[cptr] = (ArrayList)formatter.Deserialize(stream);
cptr++;
}
stream.Close();
return true;
}

Simply iterate through each object in binary file
using (System.IO.FileStream fs = new System.IO.FileStream("D:\\text\\studentdata.txt", System.IO.FileMode.Open, System.IO.FileAccess.Read))
{
System.Runtime.Serialization.Formatters.Binary.BinaryFormatter sf = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
Object o = sf.Deserialize(fs);
while (fs.Position < fs.Length)
{
o = sf.Deserialize(fs);
Student student = (o as Student);
Console.WriteLine("str: {0}", student.sname);
}
}

XmlWriter.Create not creating object in stream

System.Runtime.Serialization.DataContractSerializer ser = new System.Runtime.Serialization.DataContractSerializer(obj.GetType());
MemoryStream ms = new MemoryStream();
XmlWriter xdw = XmlWriter.Create(ms);
ser.WriteObject(xdw, obj);
Length of ms is 0
Why?

That works:
class Program
{
static void Main(string[] args)
{
var obj = "bugaga!";
System.Runtime.Serialization.DataContractSerializer ser = new System.Runtime.Serialization.DataContractSerializer(obj.GetType());
MemoryStream ms = new MemoryStream();
using (XmlWriter xdw = XmlWriter.Create(ms))
{
ser.WriteObject(xdw, obj);
}
Console.WriteLine(ms.Length);
}
}
[update] or just do xdw.Flush(), as already noticed

C# Custom Serialization/Deserialization together with DeflateStreams

I'm trying to do custom serialization/deserialization of an object as well as compressing/decompressing the serialized data with DeflateStreams. I originally did this for more complex objects but cut it down to try and figure out the problem, however it just became more puzzling as it is still there. Here is the class to be serialized/deserialized:
[Serializable]
public class RandomObject : ISerializable
{
public String Name { get; set; }
public String SavePath { get; set; }
public RandomObject()
{
}
public RandomObject(String name, String savepath)
{
Name = name;
SavePath = savepath;
}
public RandomObject(SerializationInfo info, StreamingContext context)
: this(info.GetString("name"), info.GetString("savepath"))
{
}
[SecurityPermissionAttribute(SecurityAction.Demand, SerializationFormatter = true)]
public void GetObjectData(SerializationInfo info, StreamingContext context)
{
info.AddValue("name", Name);
info.AddValue("savepath", SavePath);
}
}
And here is the code that is supposed to serialize it(which seems to work):
BinaryFormatter bf = new BinaryFormatter();
using (MemoryStream ms = new MemoryStream())
{
bf.Serialize(ms, profile);
using (DeflateStream ds = new DeflateStream(ms, CompressionMode.Compress))
{
try
{
using (FileStream fs = File.Create(path))
{
ds.Flush();
Miscellaneous.CopyStream(ds.BaseStream, fs);
fs.Flush();
fs.Close();
}
}
catch (IOException e)
{
MessageBox.Show(e.Message);
success = false;
}
ds.Close();
}
ms.Close();
}
And here is the deserialization:
RandomObject profile = null;
using (FileStream fs = File.OpenRead(path))
{
using (DeflateStream ds = new DeflateStream(fs, CompressionMode.Decompress))
{
BinaryFormatter bf = new BinaryFormatter();
ds.Flush();
using (MemoryStream ms = new MemoryStream())
{
Miscellaneous.CopyStream(ds.BaseStream, ms);
profile = bf.Deserialize(ms) as RandomObject;
profile.SavePath = path;
ms.Close();
}
ds.Close();
}
fs.Close();
}
Now, to the problem. Deserialization throws a SerializationException with the message {"No map for object '201326592'."} I have no idea how to troubleshoot or figure out what exactly is causing the problem. Very basic serialization works when I just run BinaryFormatter's Serialize and Deserialize methods on the same MemoryStream.
I tried removing the DeflateStream stuff from both methods, but it's still the same problem. When I look at the examples at MSDN and other places it looks like I'm doing it just right, and googling for the exception message doesn't give any meaningful results(or perhaps I'm just bad at searching).
PS. As you can see I use Miscellaneous.CopyStream(src, dest) which is a basic stream copier, as I can't get src.CopyTo(dest) to work at all, so any hints on that is welcome as well.
Below is a link to the whole VS2010 project if you would like to look at it more closely:
http://www.diredumplings.com/SerializationTesting.zip
UPDATE:
The_Smallest: I tried using the Compress method you posted on my serialization:
BinaryFormatter bf = new BinaryFormatter();
using (MemoryStream stream = new MemoryStream())
{
bf.Serialize(stream, profile);
byte[] array = Compress(stream);
using (MemoryStream ms = new MemoryStream(array))
{
using (FileStream fs = File.Create(path))
{
ms.WriteTo(fs);
fs.Flush();
}
}
}
However, it seems to give me the same problems that I had with srcStream.CopyTo(destStream) earlier, which is that it doesn't seem to get written to the stream. The result is a 0 kb file when I try to save it to disk. Any ideas?
Pieter: I removed the MemoryStream from the deserialization method and it seems have the same functionality as before. However I'm not sure how to implement the serialization the way you suggested. Is this what you had in mind?
BinaryFormatter bf = new BinaryFormatter();
using (FileStream fs = File.Create(path))
{
using (DeflateStream ds = new DeflateStream(fs, CompressionMode.Compress))
{
bf.Serialize(ds, profile);
fs.Flush();
ds.Close();
}
fs.Close();
}
Thanks to both of you!

I dowloaded you example and digged a little in there. See changes for your project below:
Replace LoadFromFile in Loader.cs
private static RandomObject LoadFromFile(string path)
{
try
{
var bf = new BinaryFormatter();
using (var fileStream = File.OpenRead(path))
using (var decompressed = new MemoryStream())
{
using (var deflateStream = new DeflateStream(fileStream, CompressionMode.Decompress))
deflateStream.CopyTo(decompressed);
decompressed.Seek(0, SeekOrigin.Begin);
var profile = (RandomObject)bf.Deserialize(decompressed);
profile.SavePath = path;
return profile;
}
}
catch (IOException e)
{
MessageBox.Show(e.Message);
return null;
}
}
Replace Save in Saver.cs as follows:
public static bool Save(RandomObject profile, String path)
{
try
{
var bf = new BinaryFormatter();
using (var uncompressed = new MemoryStream())
using (var fileStream = File.Create(path))
{
bf.Serialize(uncompressed, profile);
uncompressed.Seek(0, SeekOrigin.Begin);
using (var deflateStream = new DeflateStream(fileStream, CompressionMode.Compress))
uncompressed.CopyTo(deflateStream);
}
return true;
}
catch (IOException e)
{
MessageBox.Show(e.Message);
return false;
}
}

You should serialize into the DeflateStream, not the base (MemoryStream) stream.
For serializing: begin with the File.Create. Then around that stream, create the DeflateStream. Then to the DefaulteStream, serialize your objects.
For deserializing: do not create the MemoryStream and deserialize directly from the DeflateStream.
I believe there is no need for the added MemoryStream. If however you do have problems writing directly to/reading directly from the file streams, just change the serialize routine to write to the DeflateStream instead of the MemoryStream.
That should solve your issues.

There is error in streams logics, while compressing you should write to CompressStream, which writes to MemoryStream, after this you will have result in MemoryStream (not in CompressStream)
Here is example how to compress and decompress bytes
private static byte[] Compress(Stream stream)
{
using (var resultStream = new MemoryStream())
{
using (var gzipStream = new DeflateStream(resultStream, CompressionMode.Compress))
stream.CopyTo(gzipStream);
return resultStream.ToArray();
}
}
private static byte[] Decompress(byte[] bytes)
{
using (var readStream = new MemoryStream(bytes))
using (var resultStream = new MemoryStream())
{
using (var gzipStream = new DeflateStream(readStream, CompressionMode.Decompress))
gzipStream.CopyTo(resultStream);
return resultStream.ToArray();
}
}

"Binary stream does not contain a valid BinaryHeader" error on (de)serialization?

I am created a post before " Object to byte not working " .
I fixed problems that users said me , but there is still problem .
Error Message : The constructor to deserialize an object of type 'WindowsFormsApplication1.Form1+Item' was not found.;
void start()
{
Item item = new Item();
item.files.Add(#"test");
byte[] b = ObjectToByteArray(item);
Item k = Desriles(b);
}
[Serializable]
public class Item : ISerializable
{
public Item()
{
files = new List<string>();
Exclude = false;
CleanEmptyFolder = false;
}
public List<string> files;
public string MusicProfileName;
public bool Exclude;
#region ISerializable Members
public void GetObjectData(SerializationInfo info, StreamingContext context)
{
info.AddValue("files", files);
info.AddValue("MusicProfileName", MusicProfileName);
info.AddValue("Exclude", Exclude);
}
#endregion
}
public byte[] ObjectToByteArray(object _Object)
{
using (var stream = new MemoryStream())
{
// serialize object
var formatter = new BinaryFormatter();
formatter.Serialize(stream, _Object);
// get a byte array
var bytes = new byte[stream.Length];
using (BinaryReader br = new BinaryReader(stream))
{
bytes = br.ReadBytes(Convert.ToInt32(stream.Length));
}
return bytes;
}
}
public Item Desriles(byte[] items)
{
using (MemoryStream stream = new MemoryStream())
{
stream.SetLength(items.LongLength);
stream.write(items, 0, items.Length);
var formatter = new BinaryFormatter();
stream.Seek(0, SeekOrigin.Begin);
object item = formatter.Deserialize(stream); // Here I will get error
return (Item)item;
}
}

The serialization code can't work properly, you forgot to reset the stream back to the beginning. The better mouse trap:
public byte[] ObjectToByteArray(object _Object) {
using (var stream = new MemoryStream()) {
var formatter = new BinaryFormatter();
formatter.Serialize(stream, _Object);
return stream.ToArray();
}
}
The deserialization code can similarly be simplified:
public Item Desriles(byte[] items) {
using (MemoryStream stream = new MemoryStream(items)) {
var formatter = new BinaryFormatter();
return (Item)formatter.Deserialize(stream);
}
}
And you don't need GetObjectData().

In this section:
using (MemoryStream stream = new MemoryStream())
{
stream.SetLength(items.LongLength);
stream.Read(items, 0, items.Length);
[...]
object item = formatter.Deserialize(stream);
it seems you are creating a new, empty memory stream, then attempting to read from it, and Deserialize from it.
Of course it fails. The stream is empty.

abelenky makes a good point, but I don't think your:
public byte[] ObjectToByteArray(object _Object)
works either.
C# Code Snippet - Object to byte array
C# Code Snippet - Byte array to object

Thanks to All :
I found problem : I should base that to ISerializable