Making a Client & Server app with UDP

Hello fellahs, as the title of this post says I'm making a client and server application. The server are supposed to handel several clients, and the communication is done true UDP.
I have got two questions concerning this. The first one is if a exception is throws in the server should I then send the exception back to the client in serialized form. If I choose to do this then I also would need to handel the exception classen to the client. Or should I send back a regular IOException and use it's init cause to define the exception which occured in the server.
The second question is concerning the multi client support. If this is going to work then I would need to time-out the connection i the server environment, and I have not a clue about how long it should be?
/thanks in regards Ali.

superdeportivo wrote:
Hello fellahs, as the title of this post says I'm making a client and server application. The server are supposed to handel several clients, and the communication is done true UDP. Out of interest why have you chosen UDP rather than TCP?
I have got two questions concerning this. The first one is if a exception is throws in the server should I then send the exception back to the client in serialized form. If I choose to do this then I also would need to handel the exception classen to the client. Or should I send back a regular IOException and use it's init cause to define the exception which occured in the server. That is up to you, you can do either. I would do the first option.
The second question is concerning the multi client support. If this is going to work then I would need to time-out the connection i the server environment, and I have not a clue about how long it should be?It should be long enough that you don't timeout a valid connection. There is no simple answer to this.

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superdeportivo wrote:
Hello fellahs, as the title of this post says I'm making a client and server application. The server are supposed to handel several clients, and the communication is done true UDP. Out of interest why have you chosen UDP rather than TCP?
I have got two questions concerning this. The first one is if a exception is throws in the server should I then send the exception back to the client in serialized form. If I choose to do this then I also would need to handel the exception classen to the client. Or should I send back a regular IOException and use it's init cause to define the exception which occured in the server. That is up to you, you can do either. I would do the first option.
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==================== Codesamples =======================>
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import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
class RegisterCustomer extends JPanel implements ActionListener
// Button for registering a customer
private JButton jbtRegister;
// Customer information panel
private CustomerPanel customerPanel; (The error is on this line and it says Field type customer panel is missing)
// Random access file
private RandomAccessFile raf;
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import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
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class ViewCustomer extends JPanel implements ActionListener
// Buttons for viewing customer information
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private long lastPos;
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// Customer Panel.java: Panel for displaying Customer information
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
public class customerPanel extends JPanel
     JTextField jtfRegistrationnumber = new JTextField(30);
     JTextField jtfSeatingcapacity = new JTextField(20);
JTextField jtfStartdateofhire = new JTextField(20);
JTextField jtfDurationofhire = new JTextField(10);
JTextField jtfManufacture = new JTextField(20);
JTextField jtfModel = new JTextField(15);
     JTextField jtfEnginesize = new JTextField(15);
JTextField jtfCharge = new JTextField(20);
JTextField jtfMileage = new JTextField(10);
// Constuct a customer panel
public customerPanel()
// Set the panel with line border
setBorder(new BevelBorder(BevelBorder.RAISED));
// Panel p1 for holding all the labels
JPanel p1 = new JPanel();
p1.setLayout(new GridLayout(3, 1));
p1.add(new JLabel("Registration number"));
p1.add(new JLabel("Seating capacity"));
p1.add(new JLabel("Start date of hire"));
p1.add(new JLabel("Duration of hire"));
p1.add(new JLabel("Manufacture"));
p1.add(new JLabel("Model"));
p1.add(new JLabel("Engine size"));
p1.add(new JLabel("Charge"));
p1.add(new JLabel("Mileage"));
// Panel jpRegistration number for registration number
JPanel jpRegistrationnumber = new JPanel();
jpRegistrationnumber.setLayout(new BorderLayout());
jpRegistrationnumber.add(new JLabel("Registration number"), BorderLayout.WEST);
jpRegistrationnumber.add(jtfRegistrationnumber, BorderLayout.CENTER);
// Panel jpSeating capacity for holding Seating capacity
JPanel jpSeatingcapacity = new JPanel();
jpSeatingcapacity.setLayout(new BorderLayout());
jpSeatingcapacity.add(new JLabel("Seating capacity"), BorderLayout.WEST);
jpSeatingcapacity.add(jtfSeatingcapacity, BorderLayout.CENTER);
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JPanel jpStartdateofhire = new JPanel();
jpStartdateofhire.setLayout(new BorderLayout());
jpStartdateofhire.add(new JLabel("Start date of hire"), BorderLayout.WEST);
jpStartdateofhire.add(jtfStartdateofhire, BorderLayout.CENTER);
// Panel jpDuration of hire for holding Duration of hire
JPanel jpDurationofhire = new JPanel();
jpDurationofhire.setLayout(new BorderLayout());
jpDurationofhire.add(new JLabel("Duration of hire"), BorderLayout.WEST);
jpDurationofhire.add(jtfDurationofhire, BorderLayout.CENTER);
// Panel p2 for holding jpRegistration number and jpSeating capacity and start date of hire and duration of hire
JPanel p2 = new JPanel();
p2.setLayout(new BorderLayout());
p2.add(jpRegistrationnumber, BorderLayout.WEST);
p2.add(jpSeatingcapacity, BorderLayout.CENTER);
p2.add(jpStartdateofhire, BorderLayout.CENTER);
p2.add(jpDurationofhire, BorderLayout.CENTER);
// Panel p3 for holding jtfManufacture and p2
JPanel p3 = new JPanel();
p3.setLayout(new BorderLayout());
p3.add(jtfManufacture, BorderLayout.CENTER);
p3.add(p2, BorderLayout.EAST);
// Panel p4 for holding jtfModel, jtfEngine size, charge and mileage and p3
JPanel p4 = new JPanel();
p4.setLayout(new GridLayout(3, 1));
p4.add(jtfModel);
p4.add(jtfEnginesize);
p4.add(jtfCharge);
p4.add(jtfMileage);
p4.add(p3);
// Place p1 and p4 into customerPanel
setLayout(new BorderLayout());
add(p1, BorderLayout.WEST);
add(p4, BorderLayout.CENTER);
// Get customer information from the text fields
public Customer getCustomer()
return new Customer(jtfRegistrationnumber.getText().trim(),
                         jtfSeatingcapacity.getText().trim(),
                              jtfStartdateofhire.getText().trim(),
                         jtfDurationofhire.getText().trim(),
                         jtfManufacture.getText().trim(),
                         jtfModel.getText().trim(),
                              jtfEnginesize.getText().trim(),
                         jtfCharge.getText().trim(),
                         jtfMileage.getText().trim());
// Set customer information on the text fields
public void setCustomer(Customer s)
jtfRegistrationnumber.setText(s.getRegistrationnumber());
jtfSeatingcapacity.setText(s.getSeatingcapacity());
jtfStartdateofhire.setText(s.getStartdateofhire());
jtfDurationofhire.setText(s.getDurationofhire());
jtfManufacture.setText(s.getManufacture());
jtfModel.setText(s.getModel());
jtfEnginesize.setText(s.getEnginesize());
jtfCharge.setText(s.getCharge());
jtfMileage.setText(s.getMileage());
Could someone please help me and tell me what these two errors mean and how I could get rid of them

Can some one take a look at this code and tell me how to get all my jlabels to line up alone side their jtf.
Because it looks like this the picture in the attached file and this is the code for it:
public customerPanel()
// Set the panel with line border
setBorder(new BevelBorder(BevelBorder.RAISED));
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JPanel p1 = new JPanel();
p1.setLayout(new GridLayout(5, 1));
p1.add(new JLabel("Registration Number:"));
p1.add(new JLabel("Seating Capacity:"));
p1.add(new JLabel("Engine Size:"));
p1.add(new JLabel("Start date of hire"));
p1.add(new JLabel("Duration of hire"));
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p2.add(jtfRegistrationnumber);
p2.add(jtfSeatingcapacity);
p2.add(jtfEnginesize);
p2.add(jtfStartdateofhire);
p2.add(jtfDurationofhire);
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//p3.add(p1, BorderLayout.WEST);
//p3.add(p2, BorderLayout.NORTH);
JPanel p4 = new JPanel();
p4.setLayout(new GridLayout(4, 1));
p4.add(new JLabel("Manufacture:"));
p4.add(new JLabel("Model:"));
p4.add(new JLabel("Mileage:"));
p4.add(new JLabel("Charge:"));
JPanel p5 = new JPanel();
p5.setLayout(new GridLayout(4, 1));
p5.add(jtfManufacture);
p5.add(jtfModel);
p5.add(jtfMileage);
p5.add(jtfCharge);
// JPanel p6 = new JPanel();
// p6.setLayout(new BorderLayout());
// p6.add(p4, BorderLayout.SOUTH);
// p6.add(p5, BorderLayout.EAST);
// Place p1 and p4 into CustomerPanel
setLayout(new BorderLayout());
add(p1, BorderLayout.WEST);
add(p2, BorderLayout.NORTH);
add(p4, BorderLayout.SOUTH);
add(p5, BorderLayout.EAST);
So could someone please help me and correct my code so that each text lable is lined up next to its jtf java text field.

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import java.awt.BorderLayout;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.net.*;
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Making a Client & Server app with UDP

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