制作即时消息程序，运行不正确？

Question

I am just running the server to ensure it works. When i run ServerTest.java, I get "Closing Connections in my TextArea", However I am expected to have "Waiting for Someone to Connect..." within the textField. Could someone tell me, what my problem is?

ServerTest.java

import javax.swing.JFrame;

public class ServerTest {

    public static void main(String[] args){
        Server Spirit = new Server();
        Spirit.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Spirit.startRunning();
    }
}

Server.java

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


public class Server extends JFrame {

private JTextField userText;
private JTextArea chatWindow;
private ObjectOutputStream output;
private ObjectInputStream input;
private ServerSocket server;
private Socket connection;

//server constructor
public Server(){
    super("SiM");
    userText = new JTextField();
    userText.setEditable(false);
    userText.addActionListener(
            new ActionListener(){
                public void actionPerformed(ActionEvent event){
                    sendMessage(event.getActionCommand());
                    userText.setText("");
                }
            }
            );
    add(userText, BorderLayout.NORTH);
    chatWindow = new JTextArea();
    add(new JScrollPane(chatWindow));
    setSize(300,150);
    setVisible(true);

}

public void startRunning(){
    try{
        server = new ServerSocket (6798, 100); // parameters port and backlog
        while(true){
            try{
                waitForConnection();//waits for a connection
                setupStreams(); //sets up connection
                whileChatting();//once connected, sends message between each other
            }catch(EOFException eofException){              
                showMessage("\n Server Ended the Connection!"); //once streams been closed by Server
            }finally{
                closeCrap();
            }
        }
    }catch(IOException ioException){
        ioException.printStackTrace();
    }


}

//connection waiting

private void waitForConnection() throws IOException{
    showMessage("Waiting for somebody to connect... \n");
    connection = server.accept(); //listens for connection made to this socket and accepts it
    showMessage("Connected to" + connection+getInetAddress().getHostName() + " \n"); //dispays ip of connected
    }

//exchange data
private void setupStreams() throws IOException{
    output = new ObjectOutputStream(connection.getOutputStream());
    output.flush(); //flushes the stream
    input = new ObjectInputStream(connection.getInputStream());
    showMessage("\n Streams Accepted \n");
}

//initiates chat
private void whileChatting() throws IOException {
    String message = "You are now Connected";
    sendMessage(message);
    ableToType(true); //allows the user to type
    do{
        try{
            message = (String) input.readObject();
            showMessage("\n"+ message); //sent messages
        }catch(ClassNotFoundException classNotFoundException){ //if something odd is sent i.e string not sent
            showMessage("\n Unknown Message Sent! \n"); 
        }
    }while(!message.equals("CLIENT - END"));
}

//closes program
private void closeCrap(){
    showMessage("\n Closing Connections... \n");
    ableToType(false);
    try{
        output.close(); //closes connection from client
        input.close(); //closes connection to client
        connection.close(); //closes socket
    }catch(IOException ioException){
        ioException.printStackTrace();
    }
}

//send message to client
private void sendMessage(String message){
    try{
        output.writeObject("ADMIN/Server -  " + message);
        output.flush();
        showMessage("\nADMIN/Server -  " + message);
    }catch(IOException ioException){
        chatWindow.append("\n Message not Sent \n");
    }

}

//update chatWindow
private void showMessage(final String text){
    SwingUtilities.invokeLater( //creates thread that will update the GUI
            new Runnable(){
                public void run(){
                    chatWindow.append(text); //adds to the end of chattWindow
                }
            }
            );
}

//to type
private void ableToType(final boolean tof){
    SwingUtilities.invokeLater( //creates thread that will update the GUI
            new Runnable(){
                public void run(){
                     userText.setEditable(tof); //updates GUI, to allow you to type
                }
            }
            );
}

}

I have been following TheNewBoston Tutorials.

Answer 1

My error was my waitForConnection() constructor

private void waitForConnection() throws IOException{
    showMessage("Waiting for somebody to connect... \n");
    connection = server.accept(); //listens for connection made to this socket and accepts it
    showMessage("Connected to" + connection+getInetAddress().getHostName() + " \n"); //dispays ip of connected
    }

On line 4 it should be "." not "+"

+ connection.getInetAddress().getHostName() +

It was a typing error.

Answer 2

Would've been nice to see the client, so we would've been able to test it ourselfes. But your structure just seems very fragile, whenever an exception pops, which it does quite often in chat programs, you're calling your closeCrap() method. so maybe you could do the following:

  public void startRunning(){
try{
    server = new ServerSocket (6798, 100); // parameters port and backlog
    while(true){
        try{
            waitForConnection();//waits for a connection
            setupStreams(); //sets up connection
            String message = whileChatting();//once connected, sends message between each other
            if(message.equals("CLIENT - END")){
                  closeCrap();
            }
        }catch(EOFException eofException){              
            showMessage("\n Server Ended the Connection!"); //once streams been closed by Server
        }
    }
}catch(IOException ioException){
    ioException.printStackTrace();
}

}

I agree that its not the most elegant, but you can allways adjust it, if it after it works :)

btw. i made this program for my 3rd semester final exam, its a huge chat program that uses graphs, trees, stacks, observer pattern, javafx etc. But if you look the right places you would be able to dig out some of the same logic that you need.