Piszę swoją pierwszą apkę z użyciem MySQL. Ze względu na to, że zawiera dużo okienek, wspomagam się graficznym kreatorem netbeansa do generowania tychże. Zrobiłem już z powodzeniem panele logowania i tym podobne, teraz chcę wypisać dane wszystkich administratorów w polu JTextField aby można było je później wybrać i przejść do edycji kont. Przy odpalaniu tego okienka, otrzymuję:
run:
Połączenie poprawne!
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at zarzadzanieKontamiAdministratorow$2.getSize(zarzadzanieKontamiAdministratorow.java:104)
at javax.swing.plaf.basic.BasicListUI.updateLayoutState(BasicListUI.java:1342)
at javax.swing.plaf.basic.BasicListUI.maybeUpdateLayoutState(BasicListUI.java:1311)
at javax.swing.plaf.basic.BasicListUI.getPreferredSize(BasicListUI.java:578)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1662)
at javax.swing.ScrollPaneLayout.layoutContainer(ScrollPaneLayout.java:791)
at java.awt.Container.layout(Container.java:1512)
at java.awt.Container.doLayout(Container.java:1501)
at java.awt.Container.validateTree(Container.java:1697)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validate(Container.java:1632)
at java.awt.Container.validateUnconditionally(Container.java:1669)
at java.awt.Window.pack(Window.java:818)
at zarzadzanieKontamiAdministratorow.initComponents(zarzadzanieKontamiAdministratorow.java:169)
at zarzadzanieKontamiAdministratorow.<init>(zarzadzanieKontamiAdministratorow.java:34)
at PanelAdministratora.jButton3ActionPerformed(PanelAdministratora.java:154)
at PanelAdministratora.access$100(PanelAdministratora.java:14)
at PanelAdministratora$2.actionPerformed(PanelAdministratora.java:71)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6533)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6298)
at java.awt.Container.processEvent(Container.java:2238)
at java.awt.Component.dispatchEventImpl(Component.java:4889)
at java.awt.Container.dispatchEventImpl(Container.java:2296)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4897)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4534)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4475)
at java.awt.Container.dispatchEventImpl(Container.java:2282)
at java.awt.Window.dispatchEventImpl(Window.java:2746)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
at java.awt.EventQueue$4.run(EventQueue.java:733)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:730)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at zarzadzanieKontamiAdministratorow$2.getSize(zarzadzanieKontamiAdministratorow.java:104)
at javax.swing.plaf.basic.BasicListUI.updateLayoutState(BasicListUI.java:1342)
at javax.swing.plaf.basic.BasicListUI.maybeUpdateLayoutState(BasicListUI.java:1311)
at javax.swing.plaf.basic.BasicListUI.getPreferredSize(BasicListUI.java:578)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1662)
at javax.swing.ScrollPaneLayout.layoutContainer(ScrollPaneLayout.java:791)
at java.awt.Container.layout(Container.java:1512)
at java.awt.Container.doLayout(Container.java:1501)
at java.awt.Container.validateTree(Container.java:1697)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validate(Container.java:1632)
at java.awt.Window.dispatchEventImpl(Window.java:2744)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
at java.awt.EventQueue$4.run(EventQueue.java:733)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:730)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at zarzadzanieKontamiAdministratorow$2.getSize(zarzadzanieKontamiAdministratorow.java:104)
at javax.swing.plaf.basic.BasicListUI.updateLayoutState(BasicListUI.java:1342)
at javax.swing.plaf.basic.BasicListUI.maybeUpdateLayoutState(BasicListUI.java:1311)
at javax.swing.plaf.basic.BasicListUI.getPreferredSize(BasicListUI.java:578)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1662)
at javax.swing.ScrollPaneLayout.layoutContainer(ScrollPaneLayout.java:791)
at java.awt.Container.layout(Container.java:1512)
at java.awt.Container.doLayout(Container.java:1501)
at java.awt.Container.validateTree(Container.java:1697)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validateTree(Container.java:1706)
at java.awt.Container.validate(Container.java:1632)
at java.awt.Window.dispatchEventImpl(Window.java:2744)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
at java.awt.EventQueue$4.run(EventQueue.java:733)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:730)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
BUILD SUCCESSFUL (total time: 7 seconds)
import java.awt.Toolkit;
import java.sql.*;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author
*/
public class zarzadzanieKontamiAdministratorow extends javax.swing.JFrame {
/**
* Creates new form zarzadzanieKontamiAdministratorow
*/
public String login;
public String haslo;
public int szer = Toolkit.getDefaultToolkit().getScreenSize().width;
public int wys = Toolkit.getDefaultToolkit().getScreenSize().height;
public zarzadzanieKontamiAdministratorow() {
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();
jButton1 = new javax.swing.JButton();
jScrollPane1 = new javax.swing.JScrollPane();
jList1 = new javax.swing.JList<>();
jButton2 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("Zarządzanie kontami administratorów");
setLocation(szer/4, wys/4);
setResizable(false);
jLabel1.setFont(new java.awt.Font("Calibri Light", 0, 24)); // NOI18N
jLabel1.setText("Zarządzanie kontami administratorów");
jLabel2.setIcon(new javax.swing.ImageIcon(getClass().getResource("/zdjecia/logo.png"))); // NOI18N
jButton1.setText("Wróć");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jList1.setBackground(new java.awt.Color(0, 0, 0));
jList1.setBorder(new javax.swing.border.MatteBorder(null));
jList1.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jList1.setForeground(new java.awt.Color(255, 255, 255));
String tab[] = null;
String polaczenieURL = "jdbc:mysql://localhost:3306/bazadanych?user=root&password=";
String query = "SELECT * FROM kontaadminow";
Connection con = null;
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection(polaczenieURL);
Statement stat = con.createStatement();
ResultSet result = stat.executeQuery(query);
System.out.println("Połączenie poprawne!");
result.last();
int ile = result.getRow();
result.first();
for (int j=0; j > ile; j++)
{
tab[j] = j + ". Imię i nazwisko: " + result.getString("imieinazwisko") + " | login: " + result.getString("login");
result.next();
}
con.close();
}
catch (Exception ex)
{
System.out.println(ex);
}
jList1.setModel(new javax.swing.AbstractListModel<String>() {
public int getSize() { return tab.length; }
public String getElementAt(int i) { return tab[i]; }
});
jScrollPane1.setViewportView(jList1);
jButton2.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jButton2.setIcon(new javax.swing.ImageIcon(getClass().getResource("/zdjecia/add_button.png"))); // NOI18N
jButton2.setText(" Dodaj nowe konto");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jButton3.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jButton3.setIcon(new javax.swing.ImageIcon(getClass().getResource("/zdjecia/edit_icon.png"))); // NOI18N
jButton3.setText("Edytuj konto");
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(40, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jButton2))
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 312, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jLabel2))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jButton1)
.addGap(29, 29, 29)))
.addContainerGap())
.addGroup(layout.createSequentialGroup()
.addGap(97, 97, 97)
.addComponent(jLabel1)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(18, 18, 18)
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jButton1))
.addGroup(layout.createSequentialGroup()
.addGap(35, 35, 35)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 180, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton2)
.addComponent(jButton3))
.addGap(0, 0, Short.MAX_VALUE)))
.addContainerGap())
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
new PanelAdministratora().setVisible(true);
this.dispose();
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
new dodajKontoAdministratora().setVisible(true);
this.dispose();
}
/**
* @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(zarzadzanieKontamiAdministratorow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(zarzadzanieKontamiAdministratorow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(zarzadzanieKontamiAdministratorow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(zarzadzanieKontamiAdministratorow.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 zarzadzanieKontamiAdministratorow().setVisible(true);
}
});
}
// 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.JList<String> jList1;
private javax.swing.JScrollPane jScrollPane1;
// End of variables declaration
}
Nie dostaję błędu, kiedy wyrzucam poniższy blok, więc jak mniemam to w nim tkwi problem
jList1.setModel(new javax.swing.AbstractListModel<String>() {
public int getSize() { return tab.length; }
public String getElementAt(int i) { return tab[i]; }
});
Będę wdzięczny za pomoc w rozwiązaniu problemu :)