我正在设计一个消息应用程序。我有一个正常运行的服务器程序。在客户端，首先我创建了由文本 Pane 和文本字段组成的 GUI。聊天正常。 然后我修改了客户端以支持提供登录文本字段、密码文本字段和签名按钮的登录工具。 因此，在登录通过身份验证后，当前 JFrame 为 setVisible(false)，并且应显示带有聊天窗口的新 JFrame 并并行建立套接字连接。已正确建立与服务器的套接字连接，但未建立所需的 GUI，即正确的 JFrame。可能是什么问题？请..请帮助..
这是我的代码..
import java.net.*;
import java.io.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.text.*;
import javax.swing.event.*;
class Swing16 extends JPanel implements ActionListener
{
public static JButton enterbutton,signin,chatbutton;
public static JTextField txt,loginname,password;
public static JTextPane textpane;
public static JScrollPane sp;
public static JLabel retrylabel;
public static String str;
public static String newline = "\n";
public static String ss = "regular";
public static StyledDocument doc,doc1;
public static Icon icon1,icon2,icon3,icon4,icon5,icon6;
public static InetAddress inet,newinet;
public static Socket s,news;
public static InputStream in,newin;
public static OutputStream chatout,newout;
public static BufferedReader newbr,chat;
public static PrintWriter chatout1,newout1;
public static int start;
public static int end;
public static int flag = 0;
public static JFrame frm;
class connecthread implements Runnable
{
Thread t;
public connecthread()
{
t = new Thread(this);
t.start();
}
public void run()
{
Swing16.makechatconnection();
}
}
class alwaysrun implements Runnable
{
Thread t;
public alwaysrun()
{
t = new Thread(this);
t.start();
}
public void run()
{
Swing16.alwaystorun();
}
}
public Swing16()
{
if(flag == 0)
{
enterbutton = new JButton("Enter");
add(enterbutton);
enterbutton.addActionListener(this);
}
else if(flag == 1)
{
loginname = new JTextField(10);
add(loginname);
password = new JTextField(10);
add(password);
signin = new JButton("SIGN IN");
add(signin);
signin.addActionListener(this);
}
else if(flag == 2)
{
chatbutton = new JButton("CHAT");
add(chatbutton);
chatbutton.addActionListener(this);
}
else if(flag == 3)
{
retrylabel = new JLabel("AUTHENTICATION FAILED! RETRY");
add(retrylabel);
loginname = new JTextField(10);
add(loginname);
password = new JTextField(10);
add(password);
signin = new JButton("SIGN IN");
add(signin);
signin.addActionListener(this);
}
else
{
GridBagLayout g = new GridBagLayout();
setLayout(g);
GridBagConstraints a = new GridBagConstraints();
a.fill = GridBagConstraints.BOTH;
a.weightx = 1.0;
a.weighty = 1.0;
textpane = new JTextPane();
add(textpane,a);
sp = new JScrollPane(textpane);
a.gridwidth = GridBagConstraints.REMAINDER;
a.fill = GridBagConstraints.BOTH;
a.weightx = 1.0;
a.weighty = 1.0;
add(sp,a);
textpane.setEditable(false);
a.fill = GridBagConstraints.HORIZONTAL;
a.anchor = GridBagConstraints.FIRST_LINE_START;
txt = new JTextField(50);
add(txt,a);
icon1 = new ImageIcon("smile.png");
icon2 = new ImageIcon("frown.png");
icon3 = new ImageIcon("gasp.png");
icon4 = new ImageIcon("grin.png");
icon5 = new ImageIcon("tongue.png");
icon6 = new ImageIcon("wink.png");
txt.addActionListener(this);
textpane.setEditorKit(new StyledEditorKit());
Swing16.initListener();
}
}
public void actionPerformed(ActionEvent ae)
{
String t;
t = ae.getActionCommand();
if(t.equals("Enter"))
{
flag = 1;
frm.dispose();
Swing16.makeGUI();
/*try
{
newinet = InetAddress.getLocalHost();
news = new Socket(newinet,1125);
newin = news.getInputStream();
newout = news.getOutputStream();
newout1 = new PrintWriter(new BufferedWriter(new OutputStreamWriter(newout)),true);
newbr = new BufferedReader(new InputStreamReader(newin));
}
catch(UnknownHostException e)
{
System.out.println("Error.....!!!" + e);
}
catch(IOException e)
{
System.out.println("Error....!!!" + e);
}*/
}
else if(t.equals("SIGN IN"))
{
String name, passwd,authenticationcode;
name = loginname.getText();
passwd = password.getText();
frm.dispose();
try
{
/*newout1.println(name);
newout1.println(passwd);
authenticationcode = newbr.readLine();
if(authenticationcode.equals("V"))
{
*/
flag = 2;
/*newbr.close();
newout1.close();
newin.close();
newout.close();
news.close();
}
else
flag = 3; */
}
catch(Exception e)
{
System.out.println(e + "I am exception in sign in block in actionPerformed funation");
}
Swing16.makeGUI();
}
else if(t.equals("CHAT"))
{
frm.dispose();
flag = 4;
Swing16.makeGUI();
new connecthread();
new alwaysrun();
}
else
{
try
{
doc1 = textpane.getStyledDocument();
str = txt.getText();
try
{
doc1.insertString(doc1.getLength(),"Me:" + str + newline,doc1.getStyle(ss));
String text=doc1.getText(start, end-start);
int i= text.indexOf(":)");
int j= text.indexOf(":(");
int k = text.indexOf(":O");
int l = text.indexOf(":D");
int m = text.indexOf(":P");
int n = text.indexOf(";)");
while(i>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+i).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon1);
doc1.remove(start+i, 2);
doc1.insertString(start+i,":)", attrs);
}
i=text.indexOf(":)", i+2);
}
while(j>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+j).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon2);
doc1.remove(start+j, 2);
doc1.insertString(start+j,":(", attrs);
}
j=text.indexOf(":(", j+2);
}
while(k>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+k).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon3);
doc1.remove(start+k, 2);
doc1.insertString(start+k,":O", attrs);
}
k=text.indexOf(":O", k+2);
}
while(l>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+l).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon4);
doc1.remove(start+l, 2);
doc1.insertString(start+l,":D", attrs);
}
l=text.indexOf(":D", l+2);
}
while(m>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+m).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon5);
doc1.remove(start+m, 2);
doc1.insertString(start+m,":P", attrs);
}
m=text.indexOf(":P", m+2);
}
while(n>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+n).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon6);
doc1.remove(start+n, 2);
doc1.insertString(start+n,":P", attrs);
}
n=text.indexOf(":P", n+2);
}
}
catch(NullPointerException e)
{
System.out.println("I am d culprit");
}
catch (Exception ble)
{
System.out.println(ble);
}
txt.setText("");
chatout1.println(str);
}
catch(NullPointerException e)
{
System.out.println("I am the culprit");
}
catch(Exception e)
{
System.out.println(e);
}
}
}
public static void initListener()
{
textpane.getDocument().addDocumentListener(new DocumentListener(){
public void insertUpdate(DocumentEvent event)
{
final DocumentEvent e=event;
if (e.getDocument() instanceof StyledDocument)
{
try
{
//doc=(StyledDocument)e.getDocument();
start= Utilities.getRowStart(textpane,Math.max(0,e.getOffset()-1));
end=Utilities.getWordStart(textpane,e.getOffset()+e.getLength());
}
catch (BadLocationException e1)
{
e1.printStackTrace();
}
}
}
public void removeUpdate(DocumentEvent e)
{
}
public void changedUpdate(DocumentEvent event)
{
}
});
}
public static void makeGUI()
{
frm = new JFrame("Chat Window");
frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frm.add(new Swing16());
frm.pack();
frm.setVisible(true);
}
public static void makechatconnection()
{
try
{
inet = InetAddress.getLocalHost();
s = new Socket(inet,1125);
in = s.getInputStream();
chatout = s.getOutputStream();
chatout1 = new PrintWriter(new BufferedWriter(new OutputStreamWriter(chatout)),true);
chat = new BufferedReader(new InputStreamReader(in));
if(chat == null)
System.out.println("sskksks");
chatout1.println("i get transmitted there..");
}
catch(UnknownHostException e)
{
System.out.println("Error.....!!!" + e);
}
catch(IOException e)
{
System.out.println("Error....!!!" + e);
}
}
public static void alwaystorun()
{
try
{
while(true)
{
String ss1=null;
ss1 = chat.readLine();
if(chat == null)
System.out.println("hey");
System.out.println(ss1);
try
{
doc1 = textpane.getStyledDocument();
doc1.insertString(doc1.getLength(), ss1 + newline,doc1.getStyle(ss));
String text=doc1.getText(start, end-start);
int i=text.indexOf(":)");
int j=text.indexOf(":(");
int k = text.indexOf(":O");
int l = text.indexOf(":D");
int m = text.indexOf(":P");
int n = text.indexOf(";)");
while(i>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+i).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon1);
doc1.remove(start+i, 2);
doc1.insertString(start+i,":)", attrs);
}
i=text.indexOf(":)", i+2);
}
while(j>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+j).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon2);
doc1.remove(start+j, 2);
doc1.insertString(start+j,":(", attrs);
}
j=text.indexOf(":(", j+2);
}
while(k>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+k).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon3);
doc1.remove(start+k, 2);
doc1.insertString(start+k,":O", attrs);
}
k=text.indexOf(":O", k+2);
}
while(l>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+l).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon4);
doc1.remove(start+l, 2);
doc1.insertString(start+l,":D", attrs);
}
l=text.indexOf(":D", l+2);
}
while(m>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+m).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon5);
doc1.remove(start+m, 2);
doc1.insertString(start+m,":P", attrs);
}
m=text.indexOf(":P", m+2);
}
while(n>=0)
{
final SimpleAttributeSet attrs=new SimpleAttributeSet(doc1.getCharacterElement(start+n).getAttributes());
if (StyleConstants.getIcon(attrs)==null)
{
StyleConstants.setIcon(attrs, icon6);
doc1.remove(start+n, 2);
doc1.insertString(start+n,":P", attrs);
}
n=text.indexOf(":P", n+2);
}
}
catch (BadLocationException ble)
{
System.err.println("Couldn't insert text into text pane.");
}
}
}
catch(Exception e)
{
System.out.println(e + "Something bad happened.");
}
}
public static void main(String args[])
{
try
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
Swing16.makeGUI();
}
}
);
}
catch(Exception e)
{
System.out.println(e);
}
}
}
最佳答案
我的猜测是您遇到了并发问题，您没有在 Swing 主线程 EDT 的后台线程中进行套接字连接和通信，但这只是一个猜测，没有更多信息和代码。我建议你阅读 Concurrency in Swing在 Oracle Java 教程中。制作精良的 SwingWorker 对象可以在这里很好地工作。
编辑 1:
我在您的代码中看到的一些问题:
- 您的代码不应包含静态字段，而应包含非静态实例变量。
- 除了应该创建 1 个或几个实例然后在这些实例上调用适当方法的 main 方法之外，您的代码不应有任何静态方法。
- 你应该把这个神类分解成几个更小的类，这样你就可以分而治之。这使调试变得更加容易，我们也可以更轻松地分析您的代码。
- 您在“connectthread 内部类”中调用了 Swing15 方法。这是打印错误吗？
- 你说你有一个 NullPointerException。哪条线抛出这个？顺便说一下，你不应该尝试/捕获 NullPointerExceptions。您找到它们并消除导致它们的问题。去掉那个 try/catch。
- 考虑到所有这些静态方法和字段，我敢打赌您是从另一种非 OOP 编程语言转向 Java 的。我强烈建议您购买一些有关使用 Java 进行 OOP 编程的书籍，因为这会对您有很大帮助。
关于java - JFrame 中的问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/5954480/