Decoding UTF Issue?

Question

I am working on my android project & i have an exotic problem which makes me crazy. I am trying to convert a String to Utf-16 or Utf-8. I use this piece of code to achieve it but it gives me an array with some negative members!

Java Code :

String Tag="سیر";
String Value="";
try{
            byte[] bytes = Tag.getBytes("UTF-16");
            for(int i=0;i<bytes.length;i++){
            Value=Value+String.valueOf(bytes[i])+",";
        }

Array members : Array members are [-1,-2,51,6,-52,6,49,6]. I checked the UTF-16's table . It doesn't have any negative number and also I used a website which converts words to UTF-16M. It gave me "0633 06CC 0631"HEX. If you change this number to decimal you will see this: "1577 1740 1585". as you see there is no negative number here! So my first question is what are these negative numbers?!

Why do i want to convert a word to UTF-8 or UTF-16 ?

I am working on a project . this project hast two parts. First part is an android application which sends key words to the server. The words are sent by clients. My clients use (persian,فارسی ) characters. the second part is a web application which is made by C# & it has to response to my clients .

Problem: When I send these words to the server it works on a stream of "????" instead of the correct word. I have tried many ways to solve this problem but they couldn't solve it. after that i decided to send the utf-16 or utf-8 of string myself to the server and convert it to the correct word. So I chose those method which i described at the top of my post.

Is my original code reliable?

Yes it is. If I use the English characters it responses very well.

What are my original codes ?

Java codes which send parameter to the server :

    protected String doInBackground(String...Urls){
                String Data="";
                HttpURLConnection urlConnection = null; 
                try{
                    URL myUrl=new URL("http://10.0.2.2:80/Urgence/SearchResault.aspx?Tag="+Tag);
                    urlConnection = (HttpURLConnection)myUrl.openConnection();      
                    BufferedReader in = new BufferedReader (new InputStreamReader(urlConnection.getInputStream()));         
                    String temp=""; 
                    // Data is used to store Server's Response 
                    while((temp=in.readLine())!=null)
                    {               
                         Data=Data+temp;        
                    }    
                }

C# codes which response to the clients :

    string Tag = Request.QueryString["Tag"].ToString();
    SqlConnection con = new SqlConnection(WebConfigurationManager.ConnectionStrings["conStr"].ToString();
            SqlCommand cmd = new SqlCommand("FetchResaultByTag");
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("@NewsTag",Tag);
            cmd.Connection = con;
            SqlDataReader DR;
            String Txt = "";
            try
            {
                con.Open();
                DR = cmd.ExecuteReader();
                while (DR.Read())
                {
                    Txt = Txt + DR.GetString(0) + "-" + DR.GetString(1) + "-" + DR.GetString(2) + "-" + DR.GetString(3) + "/";
                }
                //Response.Write(Txt);
                con.Close();
            }
            catch (Exception ex)
            {
                con.Close();
                Response.Write(ex.ToString());
            }

*What do you think ? do you have any idea ?**

Answer 1

I solved it . at first i changed my java code.i converted my String to UTF-8 by using of URLEncoder class.

new java Code :

try{
            Tag=URLEncoder.encode(Tag,"UTF-8");
            }
            catch(Exception ex){
                Log.d("Er>encodeing-Problem",ex.toString());     
            } 

after that i sent it as a query String via Http Protocol

protected String doInBackground(String...Urls){
            String Data="";
            HttpURLConnection urlConnection = null; 
            try{
                URL myUrl=new URL("http://10.0.2.2:80/Urgence/SearchResault.aspx?Tag="+Tag);
                urlConnection = (HttpURLConnection)myUrl.openConnection();      
                BufferedReader in = new BufferedReader (new InputStreamReader(urlConnection.getInputStream()));         
                String temp=""; 
                // Data is used to store Server's Response 
                while((temp=in.readLine())!=null)
                {               
                     Data=Data+temp;        
                }  

and at the end i Caught in the server and decoded it .

new C# code :

     string Tag = Request.QueryString["Tag"].ToString();
     SqlConnection con = new SqlConnection(WebConfigurationManager.ConnectionStrings["conStr"].ToString());
            SqlCommand cmd = new SqlCommand("FetchResaultByTag");
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("@NewsTag",   HttpUtility.UrlDecode(Tag));
cmd.Connection = con;
        SqlDataReader DR;
        String Txt = "";
        try
        {
            con.Open();
            DR = cmd.ExecuteReader();
            while (DR.Read())
            {
                Txt = Txt + DR.GetString(0) + "-" + DR.GetString(1) + "-" + DR.GetString(2) + "-" + DR.GetString(3) + "/";
            }
            Response.Write(Txt);
            con.Close();
        }
        catch (Exception ex)
        {
            con.Close();
            Response.Write(ex.ToString());
        }