Re: pass-by-reference(of StringBuffer) to a constructor of another class

import java.io.*;
import java.net.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class Message implements Serializable
{
    String mesg;
}
class server1 extends JFrame implements ActionListener,Runnable
{
    JPanel p;
    JTextArea ta;
    JScrollPane sp;
    JLabel l;
    JTextField txt;
    JButton b;
    Socket cl;
    String str;
    ServerSocket sc;
    //Thread th;
    Socket s;
    //public String temp;

    protected ObjectInputStream client;
    protected ObjectOutputStream cli;

    server1()
    {
        super("Client Window");
        //th=new Thread(this);
        p=new JPanel();
        //temp=new Message();
        ta=new JTextArea(10,20);
        sp=new JScrollPane(ta);
        l=new JLabel("Enter Message ");
        txt=new JTextField(15);
        b=new JButton("Submit");
        try
        {
            sc=new ServerSocket(1001);
        }
        catch (Exception e)
        {
             //JOptionPane.showMessageDialog(null,"Socket Error");
        }
        p.add(sp);
        p.add(l);
        p.add(txt);
        p.add(b);
        getContentPane().add(p);
        setSize(300,300);
        setVisible(true);
        b.addActionListener(this);
        //th.start();
    }
    public void actionPerformed(ActionEvent ae)
    {
        try
        {
            str=txt.getText();
            txt.setText("");
            Message m1=new Message();
            m1.mesg=str;
            if (str.equals("")==false)
            {
                cli=new ObjectOutputStream(s.getOutputStream());
                cli.writeObject((Message)m1);
                ta.append("\nServer : "+str);
            }
        }
        catch (Exception e)
        {
             JOptionPane.showMessageDialog(null,""+e);
        }
    }
    public void run()
    {
        while (true)
        {
            try
            {
                s=sc.accept();
                Message temp=new Message();
                connection cn=new connection(s,temp);
                cn.start();
                if(cn.mm.equals("")==false)
                    ta.append("\nClient : "+cn.mm);
                JOptionPane.showMessageDialog(null,""+cn.mm);
            }
            catch (Exception e)
            {
                JOptionPane.showMessageDialog(null,"Error : "+e);
            }
            /*try
            {
                Thread.sleep(500);
            }
            catch (Exception e)
            {
            }*/
        }
    }
    public static void main(String args[])
    {
        server1 a=new server1();
        Thread th=new Thread(a);
        th.start();
    }
}
class connection extends Thread
{
    protected Socket cs;
    protected ObjectInputStream client;
    protected ObjectOutputStream cli;
    protected PrintStream ps;
    public String mm,abc;
    public connection(Socket sr,Message toser)
    {
        cs=sr;
        try
        {
            client=new ObjectInputStream(cs.getInputStream());
            //cli=new ObjectOutputStream(cs.getOutputStream());
        }
        catch (Exception e1)
        {
            try
            {
                cs.close();
            }
            catch (Exception e2)
            {
            }
        }
        mm="abc";
        //this.start();
        //toser.mesg=mm;
        /*try
        {
            toser.mesg=new String(""+mm);
        }
        catch (Exception e)
        {
            JOptionPane.showMessageDialog(null,"Error : "+e);
        }
        System.out.println("abc value : "+abc);

        JOptionPane.showMessageDialog(null,""+toser.mesg);
        JOptionPane.showMessageDialog(null,""+abc);*/
    }
    public void run()
    {
        Message msg1;
        try
        {
            for(;;)
            {
                msg1=(Message)client.readObject();
                if(msg1==null)
                    break;
                mm=msg1.mesg;
                //mm="chanti gadu";
                System.out.println("Client Message : "+mm);
                JOptionPane.showMessageDialog(null,"value : "+mm);
            }
        }
        catch (Exception e3)
        {
            JOptionPane.showMessageDialog(null,"Error : "+e3);
        }
        finally
        {
            try
            {
                cs.close();
            }
            catch (Exception e4)
            {
            }
        }
    }
}

this is new program...
how can pause the execution the of thread(that represents the server1)
until the run() of class connection is executed...