java.net.SocketException: Error

[Yohan Weerasinghe]

Hi,

Please have a look at the following two set of code, the server code and the client code

UserRegistrationServer.java

import java.sql.*;
import java.net.*;
import java.io.*;


public class UserRegistrationServer extends Thread
{
    private ServerSocket serverSocket;
    private Socket clientSocket;
    private BufferedReader in;
    private PrintStream out;
    
    private int result;
    private PreparedStatement ps;
    private String userName;
    private String password;
    private Connection con;
    
    public UserRegistrationServer()
    {
        try
        {
         serverSocket = new ServerSocket(1500);
         System.out.println("Server Started");
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        start();
       
    }
    
    public void run()
    {
        while(true)
        {
            try
            {
                clientSocket = serverSocket.accept();
                
                in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
                
                userName = in.readLine();
                password = in.readLine();
                
                System.out.println(userName);
                System.out.println(password);
                System.out.println("Output Stream OK");
                
                try
                {
                    dataBase();
                }
                catch(Exception db)
                {
                    db.printStackTrace();
                }
                
                out = new PrintStream(clientSocket.getOutputStream());
                out.println("Data Successfully Entered to the DataBase");
            }
            
            catch(Exception e)
            {
                e.printStackTrace();
            }
            finally
            {
                try
                {
                    clientSocket.close();
                }
                catch(IOException ioe)
                {
                   ioe.printStackTrace();
                }
            }
            
            try
            {
                in.close();
                out.close();
               
            }
            catch(Exception io)
            {
                io.printStackTrace();
            }
            
        }
    }
    public void dataBase()
    {
        try
        {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
            con = DriverManager.getConnection("jdbc:odbc:Employee","sa","sasasa");
            PreparedStatement ps = con.prepareStatement("insert into Validate_users values(?,?)");
            ps.setString(1, userName);
            ps.setString(2, password);
            result = ps.executeUpdate();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
    
    public static void main(String[]args)
    {
        new UserRegistrationServer();
    }
}

UserRegisterClient.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.net.*;
import java.io.*;


public class UserRegisterClient extends JFrame
{
    private JLabel userNameLabel, passwordLabel,titleLabel,confirmationLabel;
    private JTextField userNameTxt, passwordTxt;
    private JButton send;
    private FlowLayout flow, flow2,flow3;
    private GridLayout grid;
    private BorderLayout borderLayout;
    private JPanel northPanel, centerPanel, southPanel, mainCenterPanel, subSouthPanel;
    private Font f;
    private String name, password;
    
    private PrintStream out;
    private BufferedReader in;
    
    private Socket client;
    
   
    
    public UserRegisterClient()
    {
        userNameLabel = new JLabel("User Name: ");
        passwordLabel = new JLabel("Password: ");
        titleLabel = new JLabel("User Registration");
        send = new JButton("Send");
        send.addActionListener(new ButtonOperation());
        confirmationLabel = new JLabel();
        
        f = new Font("Arial",Font.BOLD,20);
        titleLabel.setFont(f);
        
        userNameTxt = new JTextField(10);
        userNameTxt.addMouseListener(new userNameTxtOperation());
        passwordTxt = new JTextField(10);
        passwordTxt.addMouseListener(new passwordTxtOperation());
        
        flow = new FlowLayout();
        flow2 = new FlowLayout();
        grid = new GridLayout(2,2,1,1);
        flow3 = new FlowLayout(FlowLayout.CENTER);
        borderLayout = new BorderLayout();
        
        // Designing the final Window//
        northPanel = new JPanel();
        northPanel.setLayout(flow);
        northPanel.add(titleLabel);
        
        centerPanel = new JPanel();
        centerPanel.setLayout(grid);
        centerPanel.add(userNameLabel);
        centerPanel.add(userNameTxt);
        centerPanel.add(passwordLabel);
        centerPanel.add(passwordTxt);
        
        southPanel = new JPanel();
        southPanel.setLayout(flow2);
        southPanel.add(send);
        
        subSouthPanel = new JPanel();
        subSouthPanel.setLayout(flow3);
        subSouthPanel.add(confirmationLabel);
        
        mainCenterPanel = new JPanel();
        mainCenterPanel.setLayout(borderLayout);
        mainCenterPanel.add(centerPanel,"Center");
        mainCenterPanel.add(subSouthPanel,"South");
        
        
        getContentPane().add(northPanel,"North");
        getContentPane().add(mainCenterPanel,"Center");
        getContentPane().add(southPanel,"South");        
        
        this.setTitle("User Registration Form");
        this.setResizable(false);
        
        
        try
        {
            client = new Socket("169.254.59.215",1500);
            
        }
        catch(IOException e)
        {
            JOptionPane.showMessageDialog(centerPanel, "Error While Connecting the Server: "+e);;
        }
        
        
        
        try
        {
            in = new BufferedReader(new InputStreamReader(client.getInputStream()));
            out = new PrintStream(client.getOutputStream());
        }
        catch(Exception e)
        {
            JOptionPane.showMessageDialog(centerPanel, "Error while establishing Streams: "+e);
        }
        
        
    }
    
    private class ButtonOperation implements ActionListener
    {
        public void actionPerformed(ActionEvent ae)
        {
            name = userNameTxt.getText();
            password = passwordTxt.getText();

            
            out.println(name);
            out.println(password);
            
            try
            {
            confirmationLabel.setText(in.readLine());
            }
            catch(IOException io)
            {
                JOptionPane.showMessageDialog(centerPanel, "Error while Recieving the reply: "+io);
                System.out.println(io);
            }
            

            
        }
    }
    
    private class userNameTxtOperation extends MouseAdapter
    {
        public void mouseClicked(MouseEvent me)
        {
            mouseOperations() ;
        }
    }
    
    private class passwordTxtOperation extends MouseAdapter
    {
        public void mouseClicked(MouseEvent me)
        {
            mouseOperations() ;
        }
    }
    
   private void mouseOperations() 
   {
       confirmationLabel.setText("");      
   }
    
    public static void main(String[]args)
    {
        try
        {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        }
        catch(Exception e)
        {
            JOptionPane.showMessageDialog(null, "GUI Error: "+e);
        }
        UserRegisterClient urc = new UserRegisterClient();
        urc.setVisible(true);
        urc.setSize(500,165);
        urc.validate();
        urc.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

In here, it is throwing an exception "java.net.SocketException: Software caused connection abort: recv failed" after the first data entry attempt, which means from the second data entry onwards. I have no idea why this is. This exception is caught in the client application. Please help me. Thanks.

[Rob Spoor]

The server closes the connection after sending its response.

Your protocol is not working. Your server accepts a new connection, reads from it, writes to it, then closes it. Your client creates a new connection, writes to it, reads from it, and then expects it to remain open.

I see two options:
1) in the server, keep the connection open. You will need a new thread that keeps reading from and writing to the connection, or you will block new connections.
2) in the client, don't store the socket and the streams globally, but reconnect and recreate the streams when pressing the button only.

[Yohan Weerasinghe]

Great, excellent and perfect!! Thanks a lot Rob Spoor!! I really appreciate your help


I am posting my corrected code for others that who seek help for the same issue

UserRegisterClient.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.net.*;
import java.io.*;


public class UserRegisterClient extends JFrame
{
    private JLabel userNameLabel, passwordLabel,titleLabel,confirmationLabel;
    private JTextField userNameTxt, passwordTxt;
    private JButton send;
    private FlowLayout flow, flow2,flow3;
    private GridLayout grid;
    private BorderLayout borderLayout;
    private JPanel northPanel, centerPanel, southPanel, mainCenterPanel, subSouthPanel;
    private Font f;
    private String name, password;
    
    private PrintStream out;
    private BufferedReader in;
    
    private Socket client;
    
   
    
    public UserRegisterClient()
    {
        userNameLabel = new JLabel("User Name: ");
        passwordLabel = new JLabel("Password: ");
        titleLabel = new JLabel("User Registration");
        send = new JButton("Send");
        send.addActionListener(new ButtonOperation());
        confirmationLabel = new JLabel();
        
        f = new Font("Arial",Font.BOLD,20);
        titleLabel.setFont(f);
        
        userNameTxt = new JTextField(10);
        userNameTxt.addMouseListener(new userNameTxtOperation());
        passwordTxt = new JTextField(10);
        passwordTxt.addMouseListener(new passwordTxtOperation());
        
        flow = new FlowLayout();
        flow2 = new FlowLayout();
        grid = new GridLayout(2,2,1,1);
        flow3 = new FlowLayout(FlowLayout.CENTER);
        borderLayout = new BorderLayout();
        
        // Designing the final Window//
        northPanel = new JPanel();
        northPanel.setLayout(flow);
        northPanel.add(titleLabel);
        
        centerPanel = new JPanel();
        centerPanel.setLayout(grid);
        centerPanel.add(userNameLabel);
        centerPanel.add(userNameTxt);
        centerPanel.add(passwordLabel);
        centerPanel.add(passwordTxt);
        
        southPanel = new JPanel();
        southPanel.setLayout(flow2);
        southPanel.add(send);
        
        subSouthPanel = new JPanel();
        subSouthPanel.setLayout(flow3);
        subSouthPanel.add(confirmationLabel);
        
        mainCenterPanel = new JPanel();
        mainCenterPanel.setLayout(borderLayout);
        mainCenterPanel.add(centerPanel,"Center");
        mainCenterPanel.add(subSouthPanel,"South");
        
        
        getContentPane().add(northPanel,"North");
        getContentPane().add(mainCenterPanel,"Center");
        getContentPane().add(southPanel,"South");        
        
        this.setTitle("User Registration Form");
        this.setResizable(false);
        
        
       
        
        
    }
    
    private class ButtonOperation implements ActionListener
    {
        public void actionPerformed(ActionEvent ae)
        {
            
             try
        {
            client = new Socket("169.254.59.215",1500);
            
        }
        catch(IOException e)
        {
            JOptionPane.showMessageDialog(centerPanel, "Error While Connecting the Server: "+e);;
        }
        
        
        
        try
        {
            in = new BufferedReader(new InputStreamReader(client.getInputStream()));
            out = new PrintStream(client.getOutputStream());
        }
        catch(Exception e)
        {
            JOptionPane.showMessageDialog(centerPanel, "Error while establishing Streams: "+e);
        }
            
            name = userNameTxt.getText();
            password = passwordTxt.getText();

            
            out.println(name);
            out.println(password);
            
            try
            {
            confirmationLabel.setText(in.readLine());
            }
            catch(IOException io)
            {
                JOptionPane.showMessageDialog(centerPanel, "Error while Recieving the reply: "+io);
                System.out.println(io);
            }
            

            
        }
    }
    
    private class userNameTxtOperation extends MouseAdapter
    {
        public void mouseClicked(MouseEvent me)
        {
            mouseOperations() ;
        }
    }
    
    private class passwordTxtOperation extends MouseAdapter
    {
        public void mouseClicked(MouseEvent me)
        {
            mouseOperations() ;
        }
    }
    
   private void mouseOperations() 
   {
       confirmationLabel.setText("");      
   }
    
    public static void main(String[]args)
    {
        try
        {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        }
        catch(Exception e)
        {
            JOptionPane.showMessageDialog(null, "GUI Error: "+e);
        }
        UserRegisterClient urc = new UserRegisterClient();
        urc.setVisible(true);
        urc.setSize(500,165);
        urc.validate();
        urc.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

UserRegistrationServer.java

import java.sql.*;
import java.net.*;
import java.io.*;


public class UserRegistrationServer extends Thread
{
    private ServerSocket serverSocket;
    private Socket clientSocket;
    
    
    public UserRegistrationServer()
    {
        try
        {
         serverSocket = new ServerSocket(1500);
         System.out.println("Server Started");
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        start();
       
    }
    
    public void run()
    {
        while(true)
        {
            try
            {
                clientSocket = serverSocket.accept();
                UserRegistrationConnection con = new UserRegistrationConnection(clientSocket);
                
            }
            catch(Exception e)
            {
                e.printStackTrace();
            }
        }
    }
    
    public static void main(String[]args)
    {
        new UserRegistrationServer();
    }
}

UserRegistrationConnection.java

import java.io.*;
import java.sql.*;
import java.net.*;

public class UserRegistrationConnection extends Thread
{
    private Socket netClient;
    
    private BufferedReader in;
    private PrintStream out;
    
    private int result;
    private PreparedStatement ps;
    private String userName;
    private String password;
    private Connection con;
    
    public UserRegistrationConnection(Socket client)
    {
        netClient = client;
        
        try
        {
            in = new BufferedReader(new InputStreamReader(netClient.getInputStream()));
             out = new PrintStream(netClient.getOutputStream());
        }
        catch(Exception e)
        {
            e.printStackTrace();
            
            try
            {
                netClient.close();
            }
            catch(Exception net)
            {
                net.printStackTrace();
            }
        }
        start();
    }
    
    public void run()
    {
        try
        {
          userName = in.readLine();
                password = in.readLine();
                
                System.out.println(userName);
                System.out.println(password);
                System.out.println("Output Stream OK");
                
                try
                {
                    dataBase();
                }
                catch(Exception db)
                {
                    db.printStackTrace();
                }
                
                out.println("Data Successfully Entered to the DataBase");
            }
            
            catch(Exception e)
            {
                e.printStackTrace();
            }

            
        
            try
            {
                in.close();
                out.close();
               
            }
            catch(Exception io)
            {
                io.printStackTrace();
            }
            
        }
    
     public void dataBase()
    {
        try
        {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
            con = DriverManager.getConnection("jdbc:odbc:Employee","sa","sasasa");
            PreparedStatement ps = con.prepareStatement("insert into Validate_users values(?,?)");
            ps.setString(1, userName);
            ps.setString(2, password);
            result = ps.executeUpdate();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
    
}

[Rob Spoor]

Glancing over this code I see two possible corrections:
1) In UserRegisterClient, close the connection after you're done with it.
2) In UserRegistrationConnection, don't start the thread if an exception occurs. Move line 40 to after line 25.

[Yohan Weerasinghe]

Great! I am on my way to correct them. Thanks a lot for helping me Rob Spoor, I really appreciate your help.

[Rob Spoor]

You're welcome.