【发布时间】：2011-11-09 20:50:10
【问题描述】：
我正在 Java 上实现一个基本的聊天服务器。其实我已经完成了一些基本的事情并试图改进它。
现在我想尝试制作一个显示谁在线的列表。我有个问题。我在JTextPane 组件上得到字符串，当我按“ENTER”时它会发送消息，但文本光标会移到下一行。我使用setCaretPosition(0);，但它没有用。
看下图就明白问题所在了。
这是我的服务器和服务器线程代码；
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
public class Server {
private ServerSocket ss;
private Socket s;
Map<Socket,DataOutputStream> list = new HashMap<Socket,DataOutputStream>();
public Server(int port_number) throws IOException{
create_Server(port_number);
}
public static void main(String[] args) throws IOException {
int port_number=23;
new Server(port_number);
}
private void create_Server(int port_number) throws IOException{
ss = new ServerSocket(port_number);
System.out.println("Server is ready!");
while(true){
s=ss.accept();
System.out.println(s.getLocalAddress().getHostName() + " was connected!");
send_con_mes();
list.put(s,new DataOutputStream(s.getOutputStream()) );
new ServerThread(s,this).start();
}
}
private void send_con_mes() throws IOException{
Set<Socket> sckt_list = list.keySet();
Iterator<Socket> itr = sckt_list.iterator();
DataOutputStream daos;
String str;
Socket sckt;
while(itr.hasNext()){
sckt=itr.next();
str = sckt.getLocalAddress().getHostName() + " was connected..." ;
daos = list.get(sckt);
daos.writeUTF(str);
}
}
public void send_to_All(String msg, Socket socket) throws IOException{
synchronized(list){
Set<Socket> sckt_list = list.keySet();
Iterator<Socket> itr = sckt_list.iterator();
DataOutputStream daos;
while(itr.hasNext()){
Socket sck = itr.next();
if(sck!=socket){
daos = list.get(sck);
daos.writeUTF(msg);
}
}
}
}
public void remove_Connection(Socket s) throws IOException{
synchronized(list){
list.remove(s);
System.out.println(s.getLocalAddress().getHostName() + " was disconnected!");
s.close();
}
}
}
import java.io.DataInputStream;
import java.io.IOException;
import java.net.Socket;
public class ServerThread extends Thread {
private Socket s;
private Server srv;
public ServerThread(Socket s,Server srv){
this.s = s;
this.srv = srv;
}
@Override
public void run() {
String msg;
DataInputStream dis;
try {
dis = new DataInputStream(s.getInputStream());
while(true){
msg = dis.readUTF();
srv.send_to_All(msg, s);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
try {
srv.remove_Connection(s);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
所以我想我必须在 server.java 中实现列表，但问题是如何传递列表并在 client.java 中使用它。这是我的客户代码：
import java.awt.Frame;
import java.awt.event.KeyEvent;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.DefaultListModel;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/*
* Client.java
*
* Created on 02.Eyl.2011, 16:46:44
*/
/**
*
* @author BURAKTAS
*/
public class Client extends javax.swing.JFrame implements Runnable {
private DataOutputStream dos;
private DataInputStream dis;
private Socket s;
private String Client_name;
private String Ip_addr;
private DefaultListModel listModel=new DefaultListModel();
/** Creates new form Client */
public Client() {
initComponents();
Screen.setEditable(false);
acc_list.setVisibleRowCount(6);
listModel.addElement(Client_name);
start_Chat();
}
@Override
public void run() {
try {
while(true){
String message = dis.readUTF();
Screen.append(message + "\n");
}
} catch (IOException ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
public void start_Chat() {
try {
Ip_addr = JOptionPane.showInputDialog("Enter the IP number of the server to connect : ");
s = new Socket(Ip_addr, 23);
Client_name = JOptionPane.showInputDialog("Enter your Nickname : ");
dis = new DataInputStream(s.getInputStream());
dos = new DataOutputStream(s.getOutputStream());
new Thread(Client.this).start();
} catch (UnknownHostException ex) {
JOptionPane.showMessageDialog(rootPane, "Socket can not connected", "ERROR", JOptionPane.ERROR_MESSAGE);
} catch (IOException ex) {
JOptionPane.showMessageDialog(rootPane, "Socket can not connected", "ERROR", JOptionPane.ERROR_MESSAGE);
start_Chat();
}
}
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
font_chooser = new javax.swing.JColorChooser();
jScrollPane1 = new javax.swing.JScrollPane();
Screen = new javax.swing.JTextArea();
Send_Button = new javax.swing.JButton();
jScrollPane2 = new javax.swing.JScrollPane();
acc_list = new javax.swing.JList();
disco_button = new javax.swing.JButton();
jScrollPane3 = new javax.swing.JScrollPane();
Text_Field = new javax.swing.JTextPane();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("BrkChat_Server vs 1.0");
setResizable(false);
Screen.setColumns(20);
Screen.setRows(5);
jScrollPane1.setViewportView(Screen);
Send_Button.setText("Send");
Send_Button.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
Send_ButtonActionPerformed(evt);
}
});
acc_list.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
acc_list.setSelectionMode(javax.swing.ListSelectionModel.SINGLE_INTERVAL_SELECTION);
jScrollPane2.setViewportView(acc_list);
disco_button.setText("Disconnect");
disco_button.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
disco_buttonActionPerformed(evt);
}
});
Text_Field.setCursor(new java.awt.Cursor(java.awt.Cursor.TEXT_CURSOR));
Text_Field.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
Text_FieldKeyPressed(evt);
}
});
jScrollPane3.setViewportView(Text_Field);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane3, javax.swing.GroupLayout.DEFAULT_SIZE, 383, Short.MAX_VALUE)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 383, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(disco_button, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 108, Short.MAX_VALUE)
.addComponent(Send_Button, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 108, Short.MAX_VALUE)
.addComponent(jScrollPane2, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 108, Short.MAX_VALUE))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 286, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 288, Short.MAX_VALUE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(Send_Button, javax.swing.GroupLayout.DEFAULT_SIZE, 79, Short.MAX_VALUE)
.addComponent(jScrollPane3, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 76, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(disco_button, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(11, 11, 11))
);
pack();
}// </editor-fold>
private void write(){
try {
Text_Field.setCaretPosition(0);
String str = Text_Field.getText();
dos.writeUTF(Client_name + " : " + str);
Screen.append(Client_name + " : " + str + "\n");
Text_Field.setText("");
} catch (IOException ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void Send_ButtonActionPerformed(java.awt.event.ActionEvent evt) {
write();
}
private void disco_buttonActionPerformed(java.awt.event.ActionEvent evt) {
try {
s.close();
this.setVisible(false);
System.exit(0);
} catch (IOException ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void Text_FieldKeyPressed(java.awt.event.KeyEvent evt) {
if(evt.getKeyCode()==KeyEvent.VK_ENTER){
write();
}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Windows".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Client.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Client.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Client.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Client.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Client().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTextArea Screen;
private javax.swing.JButton Send_Button;
private javax.swing.JTextPane Text_Field;
private javax.swing.JList acc_list;
private javax.swing.JButton disco_button;
private javax.swing.JColorChooser font_chooser;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JScrollPane jScrollPane3;
// End of variables declaration
}
如果您能帮助我，我将不胜感激。无论如何，谢谢。
【问题讨论】：
-
附注 - camelCase - 你的变量不应该以大写开头。