Enviar e receber String com Socket

package sendreceive;

import java.io.BufferedReader;
import java.io.*;
import java.net.*;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;

public class Receiver {
    private static BufferedReader SS_BF;
    public static Socket socket;
    
   public static void main() throws IOException
    {
        ServerSocket socket = new ServerSocket(9999);
        
        //Esse código abaixo faz travar o programa!
        Socket SS_Accept = socket.accept();
        //Eu acho que preciso de um método que substitua esse .accept();
        
        
        //Esse aqui não!
       SS_BF = new BufferedReader(new InputStreamReader(SS_Accept.getInputStream()));
    }
    
    public static void Reader() throws IOException
    {
       
        try {
            String temp = SS_BF.readLine();
        } catch (IOException ex) {
           System.out.println(ex.getStackTrace());
           JOptionPane.showMessageDialog(null,ex.getMessage());
           
        }
    }
    
    
}

package sendreceive;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;


   
public class Transport {
    
    
    public static String Stringa;
    public static String Stringb;
    public static int Intc;
    public static byte[] buffera;
    public static int Inti;
    public static int Intii;
    public static Socket socketCliente;
    public static BufferedReader SS_BF;
   
            DataOutputStream output = null;
            DataInputStream input = null;
    
 
    public static void main() throws IOException
    {
     socketCliente = new Socket("localhost",9999);
     Stringa = "Ola";
     Stringb = "Número";
     Intc = 5;
     send(Stringa);
        
    }
    
    
    public static void send(String a) throws IOException
    {
        PrintStream sender = new PrintStream(socketCliente.getOutputStream());
        sender.println(a);
        
        
    }
    
    
    
}

package sendreceive;

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;


public class InterfaceA extends javax.swing.JFrame {

    /** Creates new form InterfaceA */
    public InterfaceA() {
        initComponents();
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jButton1 = new javax.swing.JButton();
        jButton2 = new javax.swing.JButton();
        jButton3 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jButton1.setText("Iniciar Servidor");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jButton2.setText("Iniciar Cliente");
        jButton2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton2ActionPerformed(evt);
            }
        });

        jButton3.setText("Ler Mensagem");
        jButton3.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton3ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jButton1)
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jButton3)
                    .addComponent(jButton2))
                .addContainerGap(166, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(24, 24, 24)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jButton1)
                    .addComponent(jButton2))
                .addGap(18, 18, 18)
                .addComponent(jButton3)
                .addContainerGap(212, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        try {
            Receiver.main();
        } catch (IOException ex) {
            System.out.println(ex.getStackTrace());
        }
}                                        

private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                         
Receiver.Reader();
    // TODO add your handling code here:
}                                        

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        try {
            Transport.main();
        } catch (IOException ex) {
            System.out.println(ex.getStackTrace());
        }
    
    
}                                        

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(InterfaceA.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(InterfaceA.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(InterfaceA.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(InterfaceA.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new InterfaceA().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JButton jButton3;
    // End of variables declaration                   
}