Function calling in thread

Question

I know that every thread has it own stack which is not shared with the other threads.
Now for example, I have a program like:
Whenever a user connects to the server a separate thread is created and receive method is called.
mythread = new thread(this);
mythread.start();
public void run()
receive(3,4);
public void receive(int a, int b)
MyClass my = new MyClass();
my.add(a,b);
my.sub(a,b);
//MyClass is in separate file
public class MyClass
  public void add(int a, int b)
a+b;
public void sub(int a, int b)
a-b;
}Now my question is that, weather the functions calling i.e, add(), sub(), in receive() method will be thread safe and will be in the same thread's stack they belong ???
Edited by: Muhammad Umer on May 3, 2011 12:08 PM

Answer 1

Here is the actual code:
    public boolean startServer()
      boolean isServerStarted = true;
        try
            welcomeSocket = new ServerSocket(6789);
            //System.out.println("Server is started on : "+welcomeSocket.getInetAddress()+"and on port: "+welcomeSocket.getLocalPort());
        catch (IOException ex)
                isServerStarted = false;
                System.out.println("could not start server");
                ex.getMessage();
      while(true)
            try
                connectionSocket = welcomeSocket.accept(); // connectionSocket is class variable
                System.out.println("client connected with address: "+connectionSocket.getRemoteSocketAddress());
//                serverThread = new Thread(this);
//                serverThread.start();
               RequestHandler reqhanlder = new RequestHandler(connectionSocket);
               reqhanlder.start();
            catch (IOException ex)
                isServerStarted = false;
                System.out.println("could not start server");
                ex.getMessage();
    public void receiveData (Socket connectionSocket)
        byte [] certData = null;
        byte [] idData = new byte[13];
        try
            DataInputStream dataFromClient = new DataInputStream(connectionSocket.getInputStream());
            byte[] data =new byte[dataFromClient.available()];
            int read = dataFromClient.read(data);
            System.out.println("Data length is: "+data.length);
            if( read != -1)
                certData = new byte[data.length - idData.length];
                System.out.println("cert length is: "+certData.length);
                System.arraycopy(data, 0, certData, 0, certData.length);
                System.arraycopy(data, certData.length, idData, 0, idData.length);
                try
                    this.userCertificate = CertificateFactory.getInstance("X.509").generateCertificate(new ByteArrayInputStream(certData));
                    System.out.println("User certificate coming from card is: \n"+this.userCertificate);
                    System.out.println( caCertificate.getPublicKey() );
                    if( isOpen )
                        verifyCert = new VerifyCertificate();
                        boolean iVerified = verifyCert.verifyCertificate( userCertificate, caCertificate.getPublicKey() );
                        if( iVerified )
                            System.out.println("Certificate is verified");
                        else if( !iVerified )
                            System.out.println("Certificate is not verified");
                    else if( !isOpen)
                        System.out.println("could not set CA public key");
                catch (CertificateException ex)
                   System.out.println("could not create the certficate");
                   ex.printStackTrace();
                System.out.println("Data length is: "+data.length+"\nData received is: ");
            else
                System.out.println("Could not read data, \nData length is: "+data.length);
        catch (IOException ex)
            System.out.println("could not receive data from client");
           ex.getMessage();
public class RequestHandler extends Thread
    Socket connectionSocket;
    Server server;
    public RequestHandler(Socket connectionSocket)
        this.connectionSocket = connectionSocket;
    @Override
    public void run()
        server = new Server();
        server.receiveData(connectionSocket);
}