Sending a string array in a C# socket and receive in a Java socket

Question

As I mentioned in the title my problem is the following: I would like to send a string array in C# using sockets to a Java application which also uses sockets. I have tried to send the first and the second item of the array but when I tried to add them to an array in the Java app, the two item sticked together so I couldn't handle them as items of an array. I'm new in socket programming, so please help me how can I receive and handle the sent array in the Java app and maybe how to send them in the C# app correctly. Thank you for your help!

Regrads, Stanley.

EDIT:

The connecting parts are OK so I just post the sending parts. Probably not too professional because I was just trying:

Server:

String[] texts = new String[2];
texts[0] = "hello";
texts[1] = "world";

for (int i = 0; i < texts.Length; i++)
{
            buffer = Encoding.UTF8.GetBytes(texts[i].ToCharArray(), 0, texts[i].Length);
            nwStream.Write(buffer, 0, texts[i].Length);
}

Client: (and this is where I'm not too confident)

ArrayList<String> texts = new ArrayList<String>();
BufferedReader in;

in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
texts.add(0, in.readLine());

Maybe it's beacuse of the readLine but I'm not sure.

Answer 1

Really this is more about how you serialize and deserialize than it is about sockets itself. The hard part, connecting to a socket and sending/receiving data is taken care of.

You have to decide on the format of your data. That isn't done for you. In your case, you can use a simple line terminator like '\\n' to separate the lines of data for you. On the C# side, your formatting code would look like this:

// assumption: socket is your C# socket
using(NetworkStream str = new NetworkStream(socket))
using(StreamWriter writer = new StreamWriter(str))
{
    foreach (string line in arrayOfStrings)
    {
        // This automatically appends a new line character to the end
        // of the line
        writer.WriteLine(line);
    }
}

On the Java side you would use a similar construct. In Java, the equivalent to a StreamReader would be a BufferedReader .

// socket is your Java socket object
InputStreamReader charReader = new InputStreamReader(socket.getInputStream());
BufferedReader lineReader = new BufferedReader(charReader);

String line;
ArrayList<String> lines = new ArrayList<String>();

// readLine() reads to the first new line character or end of file
// and returns the string up to that point

while ((line = lineReader.readLine()) != null)
{
    lines.add(line);
}

// Converting to an array of strings is simple Java from here:
String[] arrayOfLines = lines.ToArray(new String[lines.size()]);

Of course things can get slightly more complicated if you want to use JSON, or some other means of sending formatted data. Thankfully both Java and C# have reliable a reliably serializer/deserializer library for those standard formats.