我正在尝试更新一个JList. 我已将其定义为使用listModel. 在这方面，它工作得很好，因为在我的main()方法中我可以向 中添加元素listModel，它们将反映在JList. 但是，我试图通过调用函数（如下）来强制使用新信息对其进行更新。这段代码根本不起作用。任何帮助，将不胜感激。
public void updateList(List<String> gamelist) {
listModel.removeAllElements();
for (int i=0;i<gamelist.size();i++) {
System.out.println(gamelist.get(i).toString());
listModel.addElement(gamelist.get(i).toString());
}
listGames.setModel(listModel);
}
public class Main extends javax.swing.JFrame {
/**
* Creates new form Main
*/
private javax.swing.JEditorPane editorWeb = new JEditorPane();
private DefaultListModel listModel = new DefaultListModel();
public Main() {
initComponents();
scrollWeb.setViewportView( editorWeb );
editorWeb.setEditable(false);
editorWeb.setSize(scrollWeb.getWidth(), scrollWeb.getHeight());
try {
editorWeb.setPage("http://www.futureretrogaming.tk/news.html");
} catch (IOException ex) {
Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
}
listModel.addElement("test");
}
我认为问题在于我正在制作一个新的 main 来从我的其他表单返回值。
public class LoginWindow extends javax.swing.JFrame {
/**
* Creates new form LoginWindow
*/
List<String> games = new ArrayList<String>();
Main program = new Main();
public LoginWindow() {
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() {
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
textUsername = new javax.swing.JTextField();
textPassword = new javax.swing.JPasswordField();
buttonLogin = new javax.swing.JButton();
jLabel1.setText("Please provide your username and password:");
jLabel1.setToolTipText("");
jLabel2.setText("Username:");
jLabel3.setText("Password:");
buttonLogin.setText("Submit");
buttonLogin.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
buttonLoginActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel1)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(textUsername))
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(textPassword, javax.swing.GroupLayout.PREFERRED_SIZE, 159, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addComponent(buttonLogin))
.addContainerGap(84, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(textUsername, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(34, 34, 34)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(textPassword, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 18, Short.MAX_VALUE)
.addComponent(buttonLogin)
.addContainerGap())
);
pack();
}// </editor-fold>
private void buttonLoginActionPerformed(java.awt.event.ActionEvent evt) {
try {
// TODO add your handling code here:
String loginurl = "http://futureretrogaming.tk/scripts/checklogin.php?username="+textUsername.getText()+"&password="+textPassword.getText();
System.out.println(loginurl);
URL checklogin = new URL(loginurl);
URLConnection yc = checklogin.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(yc.getInputStream()));
URL file2 = new URL(loginurl);
Scanner sc2 = new Scanner(file2.openStream());
String inputLine = "";
int i = 0;
while (/*(inputLine = in.readLine()) != null*/sc2.hasNext()) {
inputLine = inputLine.trim();
String input = sc2.next();
input = input.trim();
if (inputLine.equalsIgnoreCase("false") || input.equalsIgnoreCase("false")) {
JOptionPane.showMessageDialog(this,"Username or Password is incorrect. Please try again.", "Error", JOptionPane.PLAIN_MESSAGE);
break;
}
else if (inputLine.equalsIgnoreCase("empty") || input.equalsIgnoreCase("empty")) {
JOptionPane.showMessageDialog(this,"You must type in a username and a password.", "Error",JOptionPane.PLAIN_MESSAGE);
break;
}
else {
System.out.println(input);
if (games == null)
System.out.print("games is null");
games.add(input);
}
}
in.close();
if (games!=null) {
games.remove(0);
Collections.sort(games);
program.updateList(games);
}
} catch (MalformedURLException ex) {
Logger.getLogger(LoginWindow.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(LoginWindow.class.getName()).log(Level.SEVERE, null, ex);
}
}
/**
* @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 ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(LoginWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(LoginWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(LoginWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(LoginWindow.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 LoginWindow().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton buttonLogin;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JPasswordField textPassword;
private javax.swing.JTextField textUsername;
// End of variables declaration
}