Welcome to the Java Programming Forums


The professional, friendly Java community. 21,500 members and growing!


The Java Programming Forums are a community of Java programmers from all around the World. Our members have a wide range of skills and they all have one thing in common: A passion to learn and code Java. We invite beginner Java programmers right through to Java professionals to post here and share your knowledge. Become a part of the community, help others, expand your knowledge of Java and enjoy talking with like minded people. Registration is quick and best of all free. We look forward to meeting you.


>> REGISTER NOW TO START POSTING


Members have full access to the forums. Advertisements are removed for registered users.

Results 1 to 4 of 4

Thread: Problems with client/server application

  1. #1
    Junior Member
    Join Date
    Jan 2010
    Posts
    2
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default 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();
    	}
     
     
    }


  2. #2
    Administrator copeg's Avatar
    Join Date
    Oct 2009
    Location
    US
    Posts
    5,327
    Thanks
    181
    Thanked 828 Times in 771 Posts
    Blog Entries
    5

    Default Re: Problems with client/server application

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

  3. #3
    Junior Member
    Join Date
    Jan 2010
    Posts
    2
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default Re: Problems with client/server application

    Thanks for the advice, but the problem still persists. I think it might be sth with the client server part of the program
    Last edited by lori; January 15th, 2010 at 09:28 AM.

  4. #4
    Administrator copeg's Avatar
    Join Date
    Oct 2009
    Location
    US
    Posts
    5,327
    Thanks
    181
    Thanked 828 Times in 771 Posts
    Blog Entries
    5

    Default Re: Problems with client/server application

    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.

Similar Threads

  1. [SOLVED] The concept of Server and Client
    By rendy.dev in forum Java Theory & Questions
    Replies: 3
    Last Post: January 18th, 2010, 03:13 AM
  2. Replies: 1
    Last Post: December 2nd, 2009, 03:01 AM
  3. Simple server-client trouble
    By DC200 in forum Java Networking
    Replies: 3
    Last Post: November 12th, 2009, 07:16 AM
  4. RMI over SSL Client application
    By boilerchicken in forum Java Networking
    Replies: 0
    Last Post: November 10th, 2009, 06:52 AM
  5. Download a file to client from server
    By mvittalreddy in forum Java Networking
    Replies: 4
    Last Post: October 5th, 2009, 04:23 AM

Tags for this Thread