我有一个关于从代码更新Jlabel，JTextArea的问题。但是它不起作用。
说明:
我有3节课
package chatgui4;
//worked on it
import java.io.DataInputStream;
import java.io.PrintStream;
import java.io.IOException;
import java.net.Socket;
import java.net.ServerSocket;
public class MultiThreadChatServer {
private static ServerSocket serverSocket = null;
private static Socket clientSocket = null;
// This chat server can accept up to maxClientsCount clients' connections.
private static final int maxClientsCount = 10;
private static final clientThread[] threads = new clientThread[maxClientsCount];
public static void main(String args[]) {
int portNumber = 2222;
try {
serverSocket = new ServerSocket(portNumber);
System.out.println("Server Started at port: 2222");
} catch (IOException e) {
System.out.println(e);
}
// Create a client socket for each connection and pass it to a new client thread
while (true) {
try {
clientSocket = serverSocket.accept();
int i ;
for (i = 0; i < maxClientsCount; i++) {
if (threads[i] == null) {
(threads[i] = new clientThread(clientSocket, threads)).start();
break;
}
}
} catch (IOException e) {
System.out.println(e);
}//end catch
}//end while
}//end main
}//end public class MultiThreadChatServer
class clientThread extends Thread {
private DataInputStream is = null;
private PrintStream os = null;
private Socket clientSocket = null;
private final clientThread[] threads;
private int maxClientsCount;
private String fromClient;
boolean closed=false;
public clientThread(Socket clientSocket, clientThread[] threads) {
this.clientSocket = clientSocket;
this.threads = threads;
maxClientsCount = threads.length;
}
public void run() {
// maxClientsCount = this.maxClientsCount;
clientThread[] threads = this.threads;
try {
is = new DataInputStream(clientSocket.getInputStream());
os = new PrintStream(clientSocket.getOutputStream());
while(!is.readLine().isEmpty()){
fromClient = is.readLine().trim();
//System.out.println(fromClient);
String[] decodedFromClient=fromClient.split("@!");
if(decodedFromClient[1].trim().equals("server")){
if (decodedFromClient[3].trim().equals("iamonline")){
System.out.println(decodedFromClient[0]+ " connected.");
os.println("Server@!"+ decodedFromClient[0]+"@!Hello " + decodedFromClient[0]+ "@!all");
for (int i = 0; i < maxClientsCount; i++) {
if (threads[i] != null && threads[i] != this) {
threads[i].os.println("User " + decodedFromClient[0]
+ " entered.@!populateOnline@!"+"decodedFromClient[0]");
}
}
}//end if iamonline
else if(decodedFromClient[3].trim().equals("quit")){
for (int i = 0; i < maxClientsCount; i++) {
if (threads[i] != null && threads[i] != this) {
threads[i].os.println("server@!all@!" + decodedFromClient[0]
+ " left chat room @!removeOnline@!decodedFromClient[0]");
//from @! to @! msg @! work @! extra/whom==5
}
}
}
}//end if to server
else {
//while (true) {
//String line = is.readLine();
//String[] decodedLine=line.split("@!");
for (int i = 0; i < maxClientsCount; i++) {
if (threads[i] != null) {
//threads[i].os.println(decodedFromClient[0]+"@!"+decodedFromClient[1] +"@!"+chatMsg@!" + decodedFromClient[0]+": " + line);
System.out.println(fromClient);
threads[i].os.println(fromClient);
}
}
//}
}//end else if not server
}
/*temp coment
is.close();
os.close();
clientSocket.close();
*/
} catch (IOException e) {
System.out.println(e.getMessage());
}
//}//close while
}
}
iii。 ClientGUI.java
软件包chatgui4;
import java.awt.EventQueue;
import java.io.*;
import java.net.Socket;
import java.net.UnknownHostException;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;
/**
*
* @author sulav
*/
public class ClientGUI extends javax.swing.JFrame implements Runnable {
/**
* Creates new form ClientGUI
*/
private static Socket clientSocket = null;
// The output stream
private static PrintStream os = null;
// The input stream
private static DataInputStream is = null;
private static BufferedReader inputLine = null;
private static boolean closed = false;
public static String uname;
public ClientGUI() {
initComponents();
}
/**
* 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() {
jScrollPane1 = new javax.swing.JScrollPane();
jTextArea1 = new javax.swing.JTextArea();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jTextField1 = new javax.swing.JTextField();
jButton3 = new javax.swing.JButton();
jScrollPane3 = new javax.swing.JScrollPane();
jList2 = new javax.swing.JList();
jLabel3 = new javax.swing.JLabel();
jMenuBar1 = new javax.swing.JMenuBar();
jMenu1 = new javax.swing.JMenu();
jMenu2 = new javax.swing.JMenu();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));
jTextArea1.setColumns(20);
jTextArea1.setEditable(false);
jTextArea1.setRows(5);
jScrollPane1.setViewportView(jTextArea1);
jLabel1.setText("Online Users");
jLabel2.setText("Terminal");
jButton1.setText("Connect");
jButton1.setMargin(new java.awt.Insets(2, 2, 2, 2));
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton2.setText("Disconnect");
jButton2.setMargin(new java.awt.Insets(2, 2, 2, 2));
jTextField1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField1ActionPerformed(evt);
}
});
jButton3.setText("Send");
jButton3.setMargin(new java.awt.Insets(2, 2, 2, 2));
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
jList2.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "ram", "a", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
jScrollPane3.setViewportView(jList2);
jLabel3.setText("jLabel3");
jMenu1.setText("File");
jMenuBar1.add(jMenu1);
jMenu2.setText("Availability");
jMenuBar1.add(jMenu2);
setJMenuBar(jMenuBar1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 269, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(24, 24, 24)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addComponent(jScrollPane3, javax.swing.GroupLayout.PREFERRED_SIZE, 154, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 343, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createSequentialGroup()
.addGap(20, 20, 20)
.addComponent(jLabel3, javax.swing.GroupLayout.PREFERRED_SIZE, 220, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(7, 7, 7)
.addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 51, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel2)
.addGap(230, 230, 230)
.addComponent(jButton1)
.addGap(11, 11, 11)
.addComponent(jButton2)))
.addContainerGap(28, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(10, 10, 10)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jButton1)
.addComponent(jButton2)
.addGroup(layout.createSequentialGroup()
.addGap(5, 5, 5)
.addComponent(jLabel2)))
.addGap(7, 7, 7)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel1)
.addGap(6, 6, 6)
.addComponent(jScrollPane3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 183, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(36, 36, 36)
.addComponent(jButton3))
.addGroup(layout.createSequentialGroup()
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel3, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(15, 15, 15)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(23, Short.MAX_VALUE))
);
java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
setBounds((screenSize.width-491)/2, (screenSize.height-381)/2, 491, 381);
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
int portNumber = 2222;
String host = "localhost";
try {
clientSocket = new Socket(host, portNumber);
// System.out.println(clientSocket);
System.out.println("connected");
inputLine = new BufferedReader(new InputStreamReader(System.in));
os = new PrintStream(clientSocket.getOutputStream());
is = new DataInputStream(clientSocket.getInputStream());
//"from @! to @! message@! type of msg";
os.println(uname + " @! server @! " + uname + " @! iamonline");//@!@!
this.setTitle("Talk to me: "+uname);
} catch (UnknownHostException e) {
System.err.println("Don't know about host " + host);
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to the host "+ host);
}
if (clientSocket != null && os != null && is != null) {
try {
new Thread(new ClientGUI()).start();
} catch (Exception e) {
System.err.println("IOException: " + e);
}
}
}
private void jTextField1ActionPerformed(java.awt.event.ActionEvent evt) {
String typeMsg = jTextField1.getText();//@!
String selected = jList2.getSelectedValue().toString();
//System.out.print("msg sent to: "+selected+" "+typeMsg);
//os.println(uname + "@!" + selected + "@!" + typeMsg + "@!msg");
String Quit="quit";
//System.out.println(selected);
if(Quit.equalsIgnoreCase(typeMsg.trim()))
{os.println(uname + "@!" + selected + "@!" + typeMsg + "@!quit");
System.out.print("oi quit vo re");
jTextArea1.append(typeMsg);
}
else{
os.println(uname + "@!" + selected + "@!" + typeMsg + "@!msg");
//System.out.print("msg sent to: "+selected+" "+typeMsg);
jTextArea1.append(typeMsg+"\n");
}
jTextField1.setText("");
}
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
String typeMsg = jTextField1.getText();//@!
String selected = jList2.getSelectedValue().toString();
String Quit="quit";
//System.out.println(selected);
if(Quit.equalsIgnoreCase(typeMsg.trim()))
{os.println(uname + "@!" + selected + "@!" + typeMsg + "@!quit");
System.out.print("oi quit vo re");
jTextArea1.append(typeMsg);
}
else{
os.println(uname + "@!" + selected + "@!" + typeMsg + "@!msg");
// System.out.print("msg sent to: "+selected+" "+typeMsg);
jTextArea1.append(typeMsg+"\n");
}
jTextField1.setText("");
}
public static void main(String args[]) {
System.out.println("lau main() vitra po chirecha ta.achamma hai:0)");
/*
* 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 ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(ClientGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(ClientGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(ClientGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(ClientGUI.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 ClientGUI().setVisible(true);
System.out.println("lau yo ni printed lol");
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JList jList2;
private javax.swing.JMenu jMenu1;
private javax.swing.JMenu jMenu2;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane3;
private javax.swing.JTextArea jTextArea1;
private javax.swing.JTextField jTextField1;
// End of variables declaration
String responseLine;
@Override
public void run() {
/*
* Keep on reading from the socket till we receive "Bye" from the
* server. Once we received that then we want to break.
*/
System.out.println("aba yo print vayo hai");
// String responseLine;
try {
while ((responseLine = is.readLine().trim()) != null) {
String[] decodedResponseLine = responseLine.split("@!");
if (decodedResponseLine.length == 4) {
if (decodedResponseLine[1].trim().equals(uname)) {
System.out.println("jkjlkjkljjjjjjjjjj"+java.awt.EventQueue.isDispatchThread());
jTextArea1.setText("aayooooooooo hai");
jLabel3.setText(decodedResponseLine[2].toString().trim());
}
} else if (decodedResponseLine.length == 3) {
//jList1.
} else if (decodedResponseLine.length == 5) {
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
System.out.println("EDT running here "+java.awt.EventQueue.isDispatchThread());
System.out.println("from invokelater");
jTextArea1.append(responseLine);
jLabel3.setText("suleman");
}
});
System.out.println("jkjlkjkl"+java.awt.EventQueue.isDispatchThread());
if (responseLine.indexOf("*** Bye") != -1) {
break;
}
}
closed = true;
} catch (IOException e) {
System.err.println("IOException: " + e);
}
}
}
首先运行Multithreadchatserver类，然后运行welcomescreen。如果需要，请使用“a”用户名和“a”密码登录。我认为这行不通，因为我的日期基于不在您的计算机中。
您能否告诉我，为什么我不能从ClientGui.java行号中的代码更新JTextArea和JLabel。 320和321。我将非常感谢您的帮助。
提前致谢。
上帝会保佑你。
最佳答案
问题出在ClientGUI类中。
第193行:
new Thread(new ClientGUI()).start()
应该
new Thread(this).start()
您的代码确实更新了UI组件，并且正确地在EDT上更新了新的ClientGUI(它是不可见的)，而不是已经显示的ClientGUI。