Thread: Problems with client/server application

Hi, I'm new here! I've studied Java for 1 year now but it's been only a couple of month since I've started with the client server applications. I've to do an application abt a library and I'm having some trouble. I have to search for some books from the database using advanced search with some text boxes and then the result will show up in a panel. The code seems to run correctly but when I run the client, I expect the GUI of the application to show up but it doesn't happen a thing. Not an error or anything. I wonder if you can please give me some help and watch if the code is correct esp the client server part.Thank you in advance !
p.s The code is not complete.

THE CLIENT

package javaapplication1;
 
/**
 *
 * @author Lori
 */
import java.awt.*;
 import java.awt.event.*;
 import javax.swing.*;
 import java.io.*;
 import java.net.*;
public class Biblioteke{
 
    public static void main(String[] args) {
 
    	MyFrame fr=new MyFrame();
    	fr.setTitle("Kerkimi i librave");
    	fr.connect();
    	fr.communicate();
    	fr.show();
    }
}
class MyFrame extends JFrame implements ActionListener{
	String emerserver="localhost";
	int portaserver=32007;
	Socket s;
	DataOutputStream outdrejtserver;
	BufferedReader inngaserver;
	public MyFrame(){
		final int w=1200;
		final int h=750;
		setSize(w,h);
	Container cp=getContentPane();
	JLabel l1=new JLabel();
	l1.setPreferredSize(new Dimension(50, 0));
	JLabel l2=new JLabel();
	l2.setPreferredSize(new Dimension(50, 0));
	JLabel l3=new JLabel();
	l3.setPreferredSize(new Dimension(50, 0));
	JLabel l4=new JLabel();
	l4.setPreferredSize(new Dimension(20, 0));
		panel=new JPanel();
		p1=new JPanel();
		p2=new JPanel();
		p3=new JPanel();
		p4=new JPanel();
		searchpanel=new JPanel();
		 searchpanel.setLayout(new GridLayout(5,1));
		p1.add(new JLabel("Titulli:"));
		tf1=new JTextField(15);
		p1.add(tf1);
		p1.add(l1);
	p1.add(new JLabel("Autori:"));
		tf2=new JTextField(15);
		p1.add(tf2);
		p2.add(new JLabel("Viti:"));
		tf3=new JTextField(15);
		p2.add(tf3);
		p2.add(l2);
		p2.add(new JLabel("Gjuha:"));
		tf4=new JTextField(15);
		p2.add(tf4);
		p3.add(new JLabel("Zhanri:"));
		tf5=new JTextField(15);
		p3.add(tf5);
		p3.add(l3);
		p3.add(new JLabel("Tipi:"));
		tf6=new JTextField(15);
		p3.add(tf6);
		p4.add(new JLabel("Sh.botuese:"));
		tf7=new JTextField(15);
		p4.add(tf7);
		p4.add(l4);
		p4.add(new JLabel("Perkthyesi:"));
		tf8=new JTextField(15);
		p4.add(tf8);
		searchpanel.add(p1);
		searchpanel.add(p2);
		searchpanel.add(p3);
		searchpanel.add(p4);
 
		panel.setLayout(new GridLayout(3,1));
		panel.add(new JLabel("                                                "));
		panel.add(new JLabel("----------------------------------------------------------------------------------------------------------------------------------------Kerkoni sipas kategorive:--------------------------------------------------------------------------------------------------------------------------------------------------"));
		panel.add(new JLabel("\n \n "));
		buton=new JButton("Kerko");
		buton.addActionListener(this);
	     buttonpanel=new JPanel();
	     buttonpanel.add(new JLabel("           "));
	     buttonpanel.add(new JLabel("           "));
	     buttonpanel.add(buton);
	     buttonpanel.add(new JLabel("           "));
	     searchpanel.add(buttonpanel);
	  	JLabel label2 = new JLabel("Label");
    label2.setPreferredSize(new Dimension(100, 100));
    JScrollPane jScrollPane = new JScrollPane(label2);
 
  resultpanel=new MyPanel();
 
    jScrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
    jScrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
 
    jScrollPane.getViewport().add(resultpanel, null);
		cp.add(panel, "North");
 
		cp.add(searchpanel, "West");
		cp.add(jScrollPane, "Center");
 
 
	}
		public void actionPerformed(ActionEvent e){
 
		Object source=e.getSource();
		if (source==buton){
 
		s1=tf1.getText();
		s2=tf2.getText();
		s3=tf3.getText();
		s4=tf4.getText();
		s5=tf5.getText();
		s6=tf6.getText();
		s7=tf7.getText();
		s8=tf8.getText();
int i=0;
	while (i<=n){
 
			resultpanel.writestr(string[i]);}
			}
 
 
		}
 
		public void communicate(){
			for(;;)
			try{
			outdrejtserver.writeBytes(s1+"\n"+s2+"\n"+s3+"\n"+s4+"\n"+s5+"\n"+s6+"\n"+s7+"\n"+s8);
		n=0;
			while(inngaserver.readLine()!=null){
			n++;
			string[n]=inngaserver.readLine();
s.close();
 
                        }
 
		}
		catch(Exception ex){
				System.out.println(ex.getMessage());
				System.out.println("Gabim gjate komunikimit me server!");
				System.exit(1);
			}
	}
	public Socket connect(){
 
 
		try {
 
			s= new Socket( emerserver , portaserver) ;
		outdrejtserver = new DataOutputStream ( s.getOutputStream());
			inngaserver = new BufferedReader (new InputStreamReader ( s.getInputStream()));
		}
 
		catch (UnknownHostException ex ) {
 
			System.err.println(" Hosti i panjohur ") ;
	}
 
	catch ( Exception ex )
	{
 
		System.out.println(ex.getMessage());
			System.out.println("Gabim gjate lidhjes!");
		System.exit(1) ;
	}
	return s;
 
}
 
	private JPanel panel;
	private MyPanel resultpanel;
	private JPanel searchpanel;
	private JPanel buttonpanel;
    private JLabel label;
    private JTextField tf1;
    private JTextField tf2;
    private JTextField tf3;
    private JTextField tf4;
    private JTextField tf5;
    private JTextField tf6;
    private JTextField tf7;
    private JTextField tf8;
    private JPanel p1;
    private JPanel p2;
    private JPanel p3;
    private JPanel p4;
    private JButton buton;
    private String s1;
    private String s2;
    private String s3;
    private String s4;
    private String s5;
    private String s6;
    private String s7;
    private String s8;
    private String [] string;
    private int n;
 
 
private class WindowCloser extends WindowAdapter{
        @Override
	public void windowClosing(WindowEvent event){
		System.exit(0);
	}
}
 
 
 
}
 
class MyPanel extends JPanel{
	public MyPanel(){
		s="Rezultatet e kerkimit";
}
 
    @Override
public void paintComponent(Graphics g){
	super.paintComponent(g);
	Graphics2D g2=(Graphics2D)g;
 
	g2.drawString(s, 10,20);
 
}
public void writestr(String str){
 
 
s = str;
repaint();
 
}
private String s;
}

THE SERVER

package javaapplication1;
 
/**
 *
 * @author Lori
 */
import java.net.*;
import java.io.*;
import java.sql.*;
class ServerThread extends Thread{
ServerSocket server=null;
Socket client=null;
BufferedReader inngaklient;
DataOutputStream outdrejtklient;
public ServerThread(Socket socket)	{
	this.client=socket;}
    @Override
	public void run(){
		try{
			communication();
                        System.out.println("Serveri filloi!");
		}
		catch(Exception e){
			e.printStackTrace(System.out);
		}
 
	}
 
public void communication()throws Exception{
 
 
	try{
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
		}
		catch(ClassNotFoundException e){
			System.out.println("Error!");
			return;
		}
 
		inngaklient=new BufferedReader(new InputStreamReader(client.getInputStream()));
outdrejtklient=new DataOutputStream(client.getOutputStream());
 
for(;;){
 
String s1=inngaklient.readLine();
String s2=inngaklient.readLine();
String s3=inngaklient.readLine();
String s4=inngaklient.readLine();
String s5=inngaklient.readLine();
String s6=inngaklient.readLine();
String s7=inngaklient.readLine();
String s8=inngaklient.readLine();
 
		try{
			Connection c=DriverManager.getConnection("jdbc:odbc:lori", null, null);
			Statement s=c.createStatement();
			if(!s1.equals("")){
			ResultSet r = s.executeQuery("Select * from dbo.libra where titulli=s1");
			while(r.next()){
				outdrejtklient.writeBytes(r.getString("titulli")+"\n ");
			System.out.println("Serveri filloi");	}
			  r.close();
				s.close();
				c.close();
			}
 
 
 
 
 
		}
		catch(SQLException se){
			System.out.println("Sql exception:" +se.getMessage());
			se.printStackTrace(System.out);
		}
 
		outdrejtklient.close();
		inngaklient.close();
		client.close();	}
}
}
 
 
 
public class Multiserver {
	public void start(){
		try{
			ServerSocket servSocket=new ServerSocket(32007);
			for(;;){
				Socket socket=servSocket.accept();
				ServerThread servThread=new ServerThread(socket);
				servThread.start();
 
			}
		}
		catch(Exception e){
			System.out.println(e.getMessage());
			System.out.println("Gabim gjate krijimit te instances se serverit!");
			System.exit(1);
		}
	}
	public static void main(String[]args){
		Multiserver server=new Multiserver();
		server.start();
	}
 
 
}

The function JFrame.show is deprecated as of Java 1.5. Try changing it to setVisible(true) and see if this fixes the problem

Its tough to determine the exact problem for some cases like this. My guess is that it does have something to do with the connection and/or communication, which might be timing out or a method like read() blocking while its waiting for input. I'd suggest you do some debugging either by using a debugger and stepping through the code to see if it blocking, or commenting out some code until it works, then incrementally uncomment to try and determine the underlying problem.