所以我想创建一个简单的聊天客户端，但不知何故连接不起作用。你能帮助我吗？这就是我写的：
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.util.*;
public class game implements ActionListener{
JTextArea incoming;
JTextField outgoing;
BufferedReader reader;
PrintWriter writer;
Socket sock;
public static void main(String [] args){
game g = new game();
g.go();
}public void go(){
JFrame frame = new JFrame("Chat");
JButton sendB = new JButton("Send");
JPanel mainPanel = new JPanel();
incoming = new JTextArea(15,50);
incoming.setLineWrap(true);
incoming.setWrapStyleWord(true);
incoming.setEditable(false);
JScrollPane s = new JScrollPane(incoming);
s.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
s.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
outgoing = new JTextField(25);
sendB.addActionListener(this);
mainPanel.add(s);
mainPanel.add(outgoing);
mainPanel.add(sendB);
setUpnetworking();
Thread readerThread = new Thread( new IncomingReader());
readerThread.start();
frame.getContentPane().add(BorderLayout.CENTER, mainPanel);
frame.setVisible(true);
frame.setSize(800,500);
frame.setResizable(false);
}public void actionPerformed(ActionEvent e){
try{
writer.println(outgoing.getText());
writer.flush();
}catch(Exception ex){
ex.printStackTrace();
}
outgoing.setText("");
outgoing.requestFocus();
}public void setUpnetworking(){
try {
sock = new Socket("127.0.0.1", 5000 );
InputStreamReader streamreader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(streamreader);
writer = new PrintWriter(sock.getOutputStream());
System.out.println("Connection Established");
} catch (IOException exx) {
exx.printStackTrace();
}
}public class IncomingReader implements Runnable{
public void run(){
String message;
try{
while ((message = reader.readLine()) != null){
System.out.println("read" + message);
incoming.append(message + "\n");
}
}catch (Exception exx){exx.printStackTrace();}
}
}
}
我跑的时候遇到的错误：
java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at game.setUpnetworking(game.java:66)
at game.go(game.java:45)
at game.main(game.java:18)
java.lang.NullPointerException
at game$IncomingReader.run(game.java:79)
at java.lang.Thread.run(Unknown Source)
java.lang.NullPointerException
at game.actionPerformed(game.java:57)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$400(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
我真的不知道问题是什么:(有人可以帮助我，所以我可以建立一个有用的聊天客户端吗？我使用Eclipse。
对不好，Englisch，我来自荷兰
答案 0 :(得分：1)
对于聊天应用程序，您需要后端和客户端解决方案。 要跳过服务器端解决方案开发的部分，可以使用某些平台提供的现成的后端和SDK。那应该节省您大量的时间和精力，并且您将能够专注于UI实现。 以下是您可能会考虑使用的一些提供程序：
这里也是article比较其中一些功能的功能。
答案 1 :(得分：0)
你真的需要构建一个服务器。你需要经历一些网络。但是，如果你需要一台服务器，我几个月前就做了。单独运行。看看你是否能使它发挥作用。