您可能听说过Bucky 的使用 Java 套接字网络的 Instant Messenger 教程。127.0.0.1一个简短的总结是，他正在使用IP 地址在客户端和服务器之间创建连接。一切都对我有用，但是当我尝试更改代码并将其放在两台单独的计算机（客户端和服务器）上时，它只是没有建立连接。我究竟做错了什么？
服务器代码
import java.io.*;
import java.net.*;
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
public class Server extends JFrame{
private JTextField userTextField;
private JTextArea chatWindow;
private ObjectOutputStream output;
private ObjectInputStream input;
private ServerSocket server;
private Socket connection;
//constructor
public Server()
{
super("My Instant Messenger");
userTextField = new JTextField();
userTextField.setEditable(false);
userTextField.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent event)
{
sendMessage(event.getActionCommand());
userTextField.setText("");
}
}
);
add(userTextField, BorderLayout.NORTH);
chatWindow = new JTextArea();
add(new JScrollPane(chatWindow));
setSize(300,150);
setVisible(true);
}
//set up and run the server
public void startRunning(){
try{
server = new ServerSocket(6789,100);
while(true)
{
try{
waitForConnection();
setupStreams();
whileChatting();
}catch(EOFException e){
showMessage("\n Server ended the connection! ");
}finally{
closeCrap();
}
}
}catch(IOException e){
e.printStackTrace();
}
}
//wait for connection, then display connection information
private void waitForConnection() throws IOException{
showMessage(" Waiting for someone to connect... \n");
connection = server.accept();
showMessage(" Now Connected to " + connection.getInetAddress().getHostName());
}
//get stream to send and receive data
private void setupStreams() throws IOException{
output = new ObjectOutputStream(connection.getOutputStream());
output.flush();
input = new ObjectInputStream(connection.getInputStream());
showMessage("\n Streams are now setup! \n");
}
//during the chat coversation
private void whileChatting() throws IOException{
String message = "You are now connected!";
sendMessage(message);
ableToType(true);
do{
try{
message = (String) input.readObject();
showMessage("\n " + message);
}catch(ClassNotFoundException e){
showMessage("\n idk wtf that user sent!");
}
}while(!message.equals("CLIENT - END"));
}
//close streams and sockets after you are done chating
private void closeCrap(){
showMessage("\n Closing connection... \n");
ableToType(false);
try{
output.close();
input.close();
connection.close();
}catch(IOException e){
e.printStackTrace();
}
}
//send a message to client
private void sendMessage (String message){
try{
output.writeObject("SERVER - " + message);
output.flush();
showMessage("\nSERVER - " + message);
}catch(IOException e){
chatWindow.append("\n ERROR: DUDE I CANT SEND THAT MESSAGE!");
}
}
//update chatWindow
private void showMessage(final String text){
SwingUtilities.invokeLater(
new Runnable(){
public void run(){
chatWindow.append(text);
}
}
);
}
//let the user type stuff into their box
private void ableToType(final boolean tof){
SwingUtilities.invokeLater(
new Runnable(){
public void run(){
userTextField.setEditable(tof);
}
}
);
}
public static void main(String[] args){
Server sally = new Server();
sally.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
sally.startRunning();
}
}
客户代码
import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Client extends JFrame{
private JTextField userTextField;
private JTextArea chatWindow;
private ObjectOutputStream output;
private ObjectInputStream input;
private String message = "";
private String serverIP;
private Socket connection;
//constructor
public Client(String host){
super("Client");
serverIP = host;
userTextField = new JTextField();
userTextField.setEditable(false);
userTextField.addActionListener(
new ActionListener(){
public void actionPerformed(ActionEvent event){
sendMessage(event.getActionCommand());
userTextField.setText("");
}
}
);
add(userTextField, BorderLayout.NORTH);
chatWindow = new JTextArea();
add(new JScrollPane(chatWindow), BorderLayout.CENTER);
setSize(300,150);
setVisible(true);
}
//connect to server
public void startRunning(){
try{
connectToServer();
setUpStreams();
whileChatting();
}catch(EOFException e){
showMessage("\n Client terminated connection");
}catch(IOException e){
e.printStackTrace();
}finally{
closeCrap();
}
}
//connect to server
private void connectToServer() throws IOException{
showMessage("Attempting connection... \n");
connection = new Socket(InetAddress.getByName(serverIP), 6789);
showMessage("Connected to: " + connection.getInetAddress().getHostName());
}
//set up streams to send and receive messages
private void setUpStreams() throws IOException{
output = new ObjectOutputStream(connection.getOutputStream());
output.flush();
input = new ObjectInputStream(connection.getInputStream());
showMessage("\n Dude your streams are now good to go! \n");
}
//while chating with server
private void whileChatting() throws IOException{
ableToType(true);
do{
try{
message = (String) input.readObject();
showMessage("\n" + message);
}catch(ClassNotFoundException e){
showMessage("\n i dont know that object type");
}
}while(!message.equals("SERVER - END"));
}
//close the streams and sockets
private void closeCrap(){
showMessage("\n closing crap down...");
ableToType(false);
try{
output.close();
input.close();
connection.close();
}catch(IOException e){
e.printStackTrace();
}
}
//send messages to server
private void sendMessage(String message){
try{
output.writeObject("CLIENT - " + message);
output.flush();
showMessage("\nCLIENT - " + message);
}catch(IOException e){
chatWindow.append("\n something messed up sending message host!");
}
}
//update chatWindow
private void showMessage(final String message){
SwingUtilities.invokeLater(
new Runnable(){
public void run(){
chatWindow.append(message);
}
}
);
}
//gives user permission to type crap into the text box
private void ableToType(final boolean tof){
SwingUtilities.invokeLater(
new Runnable(){
public void run(){
userTextField.setEditable(tof);
}
}
);
}
public static void main (String[] args){
Client charlie;
charlie = new Client("127.0.0.1");
charlie.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
charlie.startRunning();
}
}