Исключение в потоке "AWT-eventqueue-0" java.lang.nullpointerexception
package qlsach;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.ButtonModel;
import javax.swing.JOptionPane;
import javax.swing.table.DefaultTableModel;
/**
*
* @author USER
*/
public final class frmQuanLySach extends javax.swing.JFrame {
DbConnect con;
private int flag = 0;
/**
* Creates new form frmQuanLySach
* @throws java.sql.SQLException
*/
public frmQuanLySach() throws SQLException {
con = new DbConnect();
showData();
}
public void ClearText(){
txtMaSach.setText("");
txtTenSach.setText("");
rbTieuThuyet.setSelected(true);
txtNXB.setText("");
cbSoTrang.setSelectedIndex(0);
txtGiaTien.setText("");
}
public void showData(){
String[] columnNames = { "Ma Sach","Ten Sach","The Loai","NXB","So Trang","Gia Tien"};
DefaultTableModel model = new DefaultTableModel();
model.setColumnIdentifiers(columnNames);
tblSach.setModel(model);
String MaSach = "";
String TenSach = "";
String TheLoai = "";
String NXB = "";
String SoTrang = "";
String GiaTien = "";
ResultSet rs = (ResultSet) con.getData("SELECT * FROM Sach");
while (rs.next()){
MaSach = rs.getString("MaSach");
TenSach = rs.getString("TenSach");
TheLoai = rs.getString("TheLoai");
NXB = rs.getString("NXB");
SoTrang = rs.getString("SoTrang");
GiaTien = rs.getString("GiaTien");
}
model.addRow(new Object[]{MaSach, TenSach, TheLoai, NXB, SoTrang, GiaTien});
}
public void InsertData(){
String TheLoai="";
ButtonModel buttonModel = buttonGroup1.getselection();
if(rbTieuThuyet.isSelected()){
TheLoai = rbTieuThuyet.getText();
}
else if(rbToanHoc.isSelected()){
TheLoai = rbToanHoc.getText();
}
else{
TheLoai = rbVanHoc.getText();
}
String SoTrang = "";
SoTrang = cbSoTrang.getSelectedItem().toString();
String[]stringsSQL = {txtTenSach.getText() , TheLoai , txtNXB.getText(), SoTrang, txtGiaTien.getText(),txtMaSach.getText()};
int isInsert = con.ExcuteSQLInsert(stringsSQL);
if(isInsert > 0){
JOptionPane.showMessageDialog(this,"Bạn Đã Thêm Dữ Liệu Thành Cônng");
}
else{
JOptionPane.showMessageDialog(this,"Bạn Chưa Thêm Được Dữ Liệu");
}
showData();
ClearText();
}
public void UpdateData(){
String TheLoai="";
ButtonModel buttonModel = buttonGroup1.getselection();
if(rbTieuThuyet.isSelected()){
TheLoai = rbTieuThuyet.getText();
}
else if(rbToanHoc.isSelected()){
TheLoai = rbToanHoc.getText();
}
else{
TheLoai = rbVanHoc.getText();
}
String SoTrang = "";
SoTrang = cbSoTrang.getSelectedItem().toString();
String[]stringsSQL = { txtMaSach.getText(), txtTenSach.getText() , TheLoai , txtNXB.getText(), SoTrang, txtGiaTien.getText()};
int isUpdate = con.ExcuteSQLUpdate(stringsSQL);
if(isUpdate > 0){
JOptionPane.showMessageDialog(this,"Bạn Đã Sửa Dữ Liệu Thành Cônng");
}
else{
JOptionPane.showMessageDialog(this,"Bạn Chưa Sửa Được Dữ Liệu");
}
showData();
ClearText();
}
public void DeleteData(){
String[]stringsSQL = { txtMaSach.getText()};
int isDelete = con.ExcuteSQLDelete(stringsSQL);
if(isDelete > 0){
JOptionPane.showMessageDialog(this,"Bạn Đã Xoá Dữ Liệu Thành Cônng");
}
else{
JOptionPane.showMessageDialog(this,"Bạn Chưa Xóa Được Dữ Liệu");
}
showData();
ClearText();
}
public void getSelectedData(){
int selectedRow = tblSach.getSelectedRow();
txtMaSach.setText(tblSach.getValueAt(selectedRow, 0).toString());
txtTenSach.setText(tblSach.getValueAt(selectedRow, 1).toString());
switch (tblSach.getValueAt(selectedRow, 2).toString()) {
case "Tiểu Thuyết":
rbTieuThuyet.setSelected(true);
break;
case "Toán Học":
rbToanHoc.setSelected(true);
break;
default:
rbVanHoc.setSelected(true);
break;
}
txtNXB.setText(tblSach.getValueAt(selectedRow, 3).toString());
cbSoTrang.setSelectedItem(tblSach.getValueAt(selectedRow, 4));
txtGiaTien.setText(tblSach.getValueAt(selectedRow, 5).toString());
}
public void getSelecttrangdau(){
int selectedRow = 0;
txtMaSach.setText(tblSach.getValueAt(selectedRow, 0).toString());
txtTenSach.setText(tblSach.getValueAt(selectedRow, 1).toString());
switch (tblSach.getValueAt(selectedRow, 2).toString()) {
case "Tiểu Thuyết":
rbTieuThuyet.setSelected(true);
break;
case "Toán Học":
rbToanHoc.setSelected(true);
break;
default:
rbVanHoc.setSelected(true);
break;
}
txtNXB.setText(tblSach.getValueAt(selectedRow, 3).toString());
cbSoTrang.setSelectedItem(tblSach.getValueAt(selectedRow, 4).toString());
txtGiaTien.setText(tblSach.getValueAt(selectedRow, 5).toString());
tblSach.setRowSelectionInterval(0, 0);
}
public void getSelecttrangtruoc(){
if(tblSach.getSelectedRow() >=1){
int selectedRow = tblSach.getSelectedRow()-1;
txtMaSach.setText(tblSach.getValueAt(selectedRow, 0).toString());
txtTenSach.setText(tblSach.getValueAt(selectedRow, 1).toString());
switch (tblSach.getValueAt(selectedRow, 2).toString()) {
case "Tiểu Thuyết":
rbTieuThuyet.setSelected(true);
break;
case "Toán Học":
rbToanHoc.setSelected(true);
break;
default:
rbVanHoc.setSelected(true);
break;
}
txtNXB.setText(tblSach.getValueAt(selectedRow, 3).toString());
cbSoTrang.setSelectedItem(tblSach.getValueAt(selectedRow, 4).toString());
txtGiaTien.setText(tblSach.getValueAt(selectedRow, 5).toString());
tblSach.setRowSelectionInterval(selectedRow, selectedRow);
}
}
public void getSelecttrangtieptheo(){
if(tblSach.getSelectedRow() < tblSach.getRowCount()-1){
int selectedRow = tblSach.getSelectedRow()-1;
txtMaSach.setText(tblSach.getValueAt(selectedRow, 0).toString());
txtTenSach.setText(tblSach.getValueAt(selectedRow, 1).toString());
switch (tblSach.getValueAt(selectedRow, 2).toString()) {
case "Tiểu Thuyết":
rbTieuThuyet.setSelected(true);
break;
case "Toán Học":
rbToanHoc.setSelected(true);
break;
default:
rbVanHoc.setSelected(true);
break;
}
txtNXB.setText(tblSach.getValueAt(selectedRow, 3).toString());
cbSoTrang.setSelectedItem(tblSach.getValueAt(selectedRow, 4).toString());
txtGiaTien.setText(tblSach.getValueAt(selectedRow, 5).toString());
tblSach.setRowSelectionInterval(selectedRow, selectedRow);
}
}
public void getSelecttrangcuoi(){
int selectedRow = tblSach.getRowCount()-1;
txtMaSach.setText(tblSach.getValueAt(selectedRow, 0).toString());
txtTenSach.setText(tblSach.getValueAt(selectedRow, 1).toString());
switch (tblSach.getValueAt(selectedRow, 2).toString()) {
case "Tiểu Thuyết":
rbTieuThuyet.setSelected(true);
break;
case "Toán Học":
rbToanHoc.setSelected(true);
break;
default:
rbVanHoc.setSelected(true);
break;
}
txtNXB.setText(tblSach.getValueAt(selectedRow, 3).toString());
cbSoTrang.setSelectedItem(tblSach.getValueAt(selectedRow, 4).toString());
txtGiaTien.setText(tblSach.getValueAt(selectedRow, 5).toString());
tblSach.setRowSelectionInterval(selectedRow, selectedRow);
}
/**
* 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();
jLabel4 = new javax.swing.JLabel();
jLabel5 = new javax.swing.JLabel();
jLabel6 = new javax.swing.JLabel();
jLabel7 = new javax.swing.JLabel();
txtMaSach = new javax.swing.JTextField();
txtTenSach = new javax.swing.JTextField();
txtNXB = new javax.swing.JTextField();
txtGiaTien = new javax.swing.JTextField();
cbSoTrang = new javax.swing.JComboBox<>();
rbTieuThuyet = new javax.swing.JRadioButton();
rbToanHoc = new javax.swing.JRadioButton();
btntrangdau = new javax.swing.JButton();
btntrangtruoc = new javax.swing.JButton();
btntrangtt = new javax.swing.JButton();
btntrangcuoi = new javax.swing.JButton();
btnluu = new javax.swing.JButton();
btnxoa = new javax.swing.JButton();
btncapnhap = new javax.swing.JButton();
btnthem = new javax.swing.JButton();
jScrollPane1 = new javax.swing.JScrollPane();
tblSach = new javax.swing.JTable();
rbVanHoc = new javax.swing.JRadioButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setFont(new java.awt.Font("Tahoma", 1, 18)); // NOI18N
jLabel1.setText("THÔNG TIN QUẢN LÝ SÁCH");
jLabel2.setText("Mã Sách:");
jLabel3.setText("Tên Sách:");
jLabel4.setText("Thể Loại:");
jLabel5.setText("NXB:");
jLabel6.setText("Số Trang:");
jLabel7.setText("Giá Tiền:");
cbSoTrang.setModel(new javax.swing.DefaultComboBoxModel<>(new String[] { "1", "2", "3", "4", "5", "6", "7" }));
rbTieuThuyet.setText("Tiểu Thuyết");
rbToanHoc.setText("Toán Học");
btntrangdau.setText("Trang Đầu");
btntrangdau.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btntrangdauActionPerformed(evt);
}
});
btntrangtruoc.setText("Trang Trước");
btntrangtruoc.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btntrangtruocActionPerformed(evt);
}
});
btntrangtt.setText("Trang Tiếp Theo");
btntrangtt.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btntrangttActionPerformed(evt);
}
});
btntrangcuoi.setText("Trang Cuối");
btntrangcuoi.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btntrangcuoiActionPerformed(evt);
}
});
btnluu.setText("Lưu");
btnluu.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btnluuActionPerformed(evt);
}
});
btnxoa.setText("Xóa");
btnxoa.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btnxoaActionPerformed(evt);
}
});
btncapnhap.setText("Cập Nhập");
btncapnhap.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btncapnhapActionPerformed(evt);
}
});
btnthem.setText("Thêm");
btnthem.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btnthemActionPerformed(evt);
}
});
tblSach.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
{null, null, null, null},
{null, null, null, null},
{null, null, null, null},
{null, null, null, null}
},
new String [] {
"Title 1", "Title 2", "Title 3", "Title 4"
}
));
tblSach.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
tblSachMouseClicked(evt);
}
});
jScrollPane1.setViewportView(tblSach);
rbVanHoc.setText("Văn Học");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(28, 28, 28)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel6, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel7, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel4, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel5, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addComponent(jLabel3, javax.swing.GroupLayout.PREFERRED_SIZE, 67, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(33, 33, 33)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addGap(123, 123, 123)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(txtNXB)
.addComponent(txtGiaTien)
.addComponent(cbSoTrang, 0, 356, Short.MAX_VALUE)))
.addGroup(layout.createSequentialGroup()
.addGap(28, 28, 28)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel1)
.addGap(105, 105, 105))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addComponent(btntrangtruoc, javax.swing.GroupLayout.PREFERRED_SIZE, 116, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(35, 35, 35)
.addComponent(btntrangtt))
.addGroup(layout.createSequentialGroup()
.addComponent(btnxoa, javax.swing.GroupLayout.PREFERRED_SIZE, 116, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(btncapnhap, javax.swing.GroupLayout.PREFERRED_SIZE, 129, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(49, 49, 49)))))
.addComponent(txtTenSach, javax.swing.GroupLayout.PREFERRED_SIZE, 356, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(txtMaSach, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 356, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(layout.createSequentialGroup()
.addGap(154, 154, 154)
.addComponent(rbVanHoc)
.addGap(18, 18, 18)
.addComponent(rbTieuThuyet)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 85, Short.MAX_VALUE)
.addComponent(rbToanHoc))))
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(btntrangdau, javax.swing.GroupLayout.PREFERRED_SIZE, 102, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(btnthem, javax.swing.GroupLayout.PREFERRED_SIZE, 102, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(btntrangcuoi, javax.swing.GroupLayout.DEFAULT_SIZE, 109, Short.MAX_VALUE)
.addComponent(btnluu, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))))
.addGap(18, 18, 18)
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 388, Short.MAX_VALUE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 514, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addGap(62, 62, 62)
.addComponent(jLabel1)
.addGap(40, 40, 40)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(txtMaSach, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(23, 23, 23)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(txtTenSach, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(20, 20, 20)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel4)
.addComponent(rbTieuThuyet)
.addComponent(rbToanHoc)
.addComponent(rbVanHoc))
.addGap(26, 26, 26)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel5)
.addComponent(txtNXB, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(27, 27, 27)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel6)
.addComponent(cbSoTrang, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(38, 38, 38)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel7)
.addComponent(txtGiaTien, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(57, 57, 57)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(btntrangdau)
.addComponent(btntrangtruoc)
.addComponent(btntrangtt)
.addComponent(btntrangcuoi))
.addGap(27, 27, 27)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(btnluu)
.addComponent(btnxoa)
.addComponent(btncapnhap)
.addComponent(btnthem))))
.addContainerGap(26, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void btntrangdauActionPerformed(java.awt.event.ActionEvent evt) {
getSelecttrangdau();
}
private void btntrangtruocActionPerformed(java.awt.event.ActionEvent evt) {
getSelecttrangtruoc();
}
private void btntrangttActionPerformed(java.awt.event.ActionEvent evt) {
getSelecttrangtieptheo();
}
private void btntrangcuoiActionPerformed(java.awt.event.ActionEvent evt) {
getSelecttrangcuoi();
}
private void btnthemActionPerformed(java.awt.event.ActionEvent evt) {
ClearText();
btnluu.setEnabled(true);
flag = 1;
btnthem.setEnabled(false);
btncapnhap.setEnabled(false);
btnxoa.setEnabled(false);
}
private void btncapnhapActionPerformed(java.awt.event.ActionEvent evt) {
ClearText();
btnluu.setEnabled(true);
flag = 2;
btnthem.setEnabled(false);
btncapnhap.setEnabled(false);
btnxoa.setEnabled(false);
}
private void btnxoaActionPerformed(java.awt.event.ActionEvent evt) {
ClearText();
btnluu.setEnabled(true);
flag = 3;
btnthem.setEnabled(false);
btncapnhap.setEnabled(false);
btnxoa.setEnabled(false);
}
private void btnluuActionPerformed(java.awt.event.ActionEvent evt) {
if (flag == 1){
InsertData();
btnthem.setEnabled(true);
btncapnhap.setEnabled(true);
btnxoa.setEnabled(true);
}
if (flag == 1){
UpdateData();
btnthem.setEnabled(true);
btncapnhap.setEnabled(true);
btnxoa.setEnabled(true);
}
else{
DeleteData();
btnthem.setEnabled(true);
btncapnhap.setEnabled(true);
btnxoa.setEnabled(true);
}
ClearText();
btnluu.setEnabled(false);
}
private void tblSachMouseClicked(java.awt.event.MouseEvent evt) {
getSelectedData();
}
/**
* @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 | InstantiationException | IllegalAccessException | javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(frmQuanLySach.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(() -> {
try {
new frmQuanLySach().setVisible(true);
} catch (SQLException ex) {
Logger.getLogger(frmQuanLySach.class.getName()).log(Level.SEVERE, null, ex);
}
});
}
Что я уже пробовал:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at qlsach.frmQuanLySach.showData(frmQuanLySach.java:43) at qlsach.frmQuanLySach.<init>(frmQuanLySach.java:29) at qlsach.frmQuanLySach.lambda$main$0(frmQuanLySach.java:585) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) 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:74) at java.awt.EventQueue.dispatchEvent(EventQueue.java:728) 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)