How can you emulate object serialization on java in C#

Question

I need to call a servlet call for an automation of a java applet using c#. What the java applet is it calls a servlet using a URL Connection object.

URL servlet = new URL(servletProtocol, servletHost, servletPort, "/" + ServletName);
URLConnection con = servlet.openConnection();
con.setDoOutput(true);
ObjectOutputStream out = new ObjectOutputStream(con.getOutputStream());
// Write several parameters strings
out.writeObject(param[0]);
out.writeObject(param[1]);
out.flush();
out.close();

The problem is i need to simulate this using c#. I believe the counterpart object would be HttpWebRequest

HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(servletPath);
myRequest.Method = "POST";
myRequest.ContentType="application/x-www-form-urlencoded";
myRequest.ContentLength = data.Length;
Stream newStream=myRequest.GetRequestStream();
// Send the data.
newStream.Write(param[0],0,param[0].length);
newStream.Write(param[1],0,param[1].length);
newStream.Close();

How do I write the string as a serialized java string? Is there any workaround here? According to the documentation of ObjectOutputStream in java, it serialize the object except for primitive type. I know String is class, so does it serialzie it like an object or some special case?

I have tried one solution, I have imported the IKVM (http://www.ikvm.net/) java virtual machine in my reference and am trying to use the java.io library in Java. Unforunately, when the ObjectInputStream constructor is called, a "invalid stream header" is thrown.

Here is my altered code:

myRequest.Method = "POST";
myRequest.ContentType = "application/x-www-form-urlencoded";
myRequest.ContentLength = data.Length;
Stream newStream = myRequest.GetRequestStream();

// Send the data.
newStream.Write(data, 0, data.Length);
newStream.Close();

List<byte> lByte = new List<byte>();
using (StreamReader sr = new StreamReader(myRequest.GetResponse().GetResponseStream()))
{
    while (sr.Peek() >= 0)
    {
        lByte.Add((byte)sr.Read());
    }
}

byte[] bArr = lByte.ToArray();
ObjectInputStream inputStream = null;

try
{
    //Construct the ObjectInputStream object
    inputStream = new ObjectInputStream(new ByteArrayInputStream(bArr));

    Object obj = null;

    while ((obj = inputStream.readObject()) != null)
    {
        string objStr = obj as string;
    }


}
catch (java.lang.Exception ex)

Answer 1

I finally got to get this to work.

The problem is on reading the data in .NET instead of using StreamReader, I need to use the Stream object immediately. Anyway just leaving it here in case it helps others with their problem:

Wrong Code:

List<byte> lByte = new List<byte>();
using (StreamReader sr = new StreamReader(myRequest.GetResponse().GetResponseStream()))
{
    while (sr.Peek() >= 0)
    {
        lByte.Add((byte)sr.Read());
    }
}

Correct Code:

byte[] buffer = new byte[1000];
using (Stream sr = myRequest.GetResponse().GetResponseStream())
{
    sr.Read(buffer, 0, 1000);
}

Answer 2

If you have control over the serialization/deserialization on the Java side, your best bet is to use a cross-platform serialization protocol such as Protocol Buffers. For C++, Java, and Python:

http://code.google.com/p/protobuf/

For .NET, Jon Skeet wrote a port:

http://code.google.com/p/protobuf-net/