我尝试将项目构建为JAR文件;但运行该文件后，会出现一条消息：“找不到主类：登录” 我查看并搜索，但没有解决方案，项目的主要类别是“登录”。
有一个班级login：
import java.sql.Connection;
import static java.sql.DriverManager.getConnection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.swing.JOptionPane;
public class login extends javax.swing.JFrame {
Connection con = null;
ResultSet rs = null;
Statement stmt = null;
public static String nu = "";
//construction de la fenetre login
public login() {
initComponents();
this.setResizable(false);
this.pack();
java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
this.setLocation(
(screenSize.width - this.getWidth()) / 2,
(screenSize.height - this.getHeight()) / 2);
}
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
Login = new javax.swing.JPanel();
jTextField1 = new javax.swing.JTextField(AppPreferences.getLastUserName());
jButton1 = new javax.swing.JButton();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jButton2 = new javax.swing.JButton();
p1 = new javax.swing.JLabel();
p2 = new javax.swing.JLabel();
jPasswordField1 = new javax.swing.JPasswordField();
jLabel3 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("Login");
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowOpened(java.awt.event.WindowEvent evt) {
formWindowOpened(evt);
}
});
Login.setBackground(new java.awt.Color(255, 255, 255));
Login.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(0, 0, 0), 1, true));
Login.setPreferredSize(new java.awt.Dimension(517, 271));
jTextField1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField1ActionPerformed(evt);
}
});
jButton1.setText("LOGIN");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton1.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyTyped(java.awt.event.KeyEvent evt) {
jButton1KeyTyped(evt);
}
});
jLabel1.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jLabel1.setText("User name");
jLabel2.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
jLabel2.setText("Password");
jButton2.setText("QUIT");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jButton2.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyTyped(java.awt.event.KeyEvent evt) {
jButton2KeyTyped(evt);
}
});
p1.setFont(new java.awt.Font("Times New Roman", 0, 14)); // NOI18N
p1.setForeground(new java.awt.Color(204, 51, 0));
p2.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
p2.setForeground(new java.awt.Color(0, 0, 255));
p2.setText(" ");
jLabel4.setIcon(new javax.swing.ImageIcon(getClass().getResource("/application/backoffice1/Ooredoo_Logo.png"))); // NOI18N
javax.swing.GroupLayout LoginLayout = new javax.swing.GroupLayout(Login);
Login.setLayout(LoginLayout);
LoginLayout.setHorizontalGroup(
LoginLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(LoginLayout.createSequentialGroup()
.addComponent(jLabel4, javax.swing.GroupLayout.PREFERRED_SIZE, 450, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(255, 255, 255)
.addComponent(jLabel3)
.addGap(0, 0, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, LoginLayout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(LoginLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(LoginLayout.createSequentialGroup()
.addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 72, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jPasswordField1, javax.swing.GroupLayout.PREFERRED_SIZE, 138, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(LoginLayout.createSequentialGroup()
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 72, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 138, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(337, 337, 337))
.addGroup(LoginLayout.createSequentialGroup()
.addGap(206, 206, 206)
.addGroup(LoginLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(LoginLayout.createSequentialGroup()
.addComponent(jButton1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jButton2))
.addGroup(LoginLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(p1, javax.swing.GroupLayout.PREFERRED_SIZE, 236, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(p2, javax.swing.GroupLayout.PREFERRED_SIZE, 153, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
LoginLayout.setVerticalGroup(
LoginLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(LoginLayout.createSequentialGroup()
.addGroup(LoginLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(LoginLayout.createSequentialGroup()
.addGap(20, 20, 20)
.addComponent(jLabel3))
.addComponent(jLabel4, javax.swing.GroupLayout.PREFERRED_SIZE, 99, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(LoginLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 20, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(LoginLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 20, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jPasswordField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(p1, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(p2, javax.swing.GroupLayout.PREFERRED_SIZE, 23, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(LoginLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jButton2)
.addComponent(jButton1))
.addContainerGap())
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(Login, javax.swing.GroupLayout.DEFAULT_SIZE, 450, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(Login, javax.swing.GroupLayout.DEFAULT_SIZE, 278, Short.MAX_VALUE)
);
pack();
}// </editor-fold>
private void formWindowOpened(java.awt.event.WindowEvent evt) {
// TODO add your handling code here:
}
/*Action du bouton QUIT activ avec la souris
Ce bouton permet de fermer la fenetre d'authentification
*/
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
System.exit(0);
}
/*Action du bouton LOGIN activ avec la souris
Ce bouton permet de valider l'identité de la personne selon les champs remplies
*/
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
try {
AppPreferences.getLastUserName();
// le meme déroulement qu'en action performed
String Sql = "Select username,password from acteur where username ='" + jTextField1.getText() + "'and password ='" + jPasswordField1.getText() + "'";
con = getConnection("jdbc:mysql://localhost:3306/base_rapport", "root", "");
stmt = con.createStatement();
rs = stmt.executeQuery(Sql);
if (rs.next()) {
AppPreferences.saveUserName(jTextField1.getText());
p2.setText("welcome " + jTextField1.getText());
nu = jTextField1.getText();
p1.setText("");
Principale s = new Principale();
s.setVisible(true);
this.dispose();
} else {
p1.setText("Invalid user name or password");
}
} catch (SQLException e) {
JOptionPane.showMessageDialog(this, "No data base connection");
}
}
/*Action du bouton LOGIN active avec la touche Eter
Ce bouton permet de valider l'identité de la personne selon les champs remplies
*/
private void jButton1KeyTyped(java.awt.event.KeyEvent evt) {
// TODO add your handling code here:
try {
AppPreferences.getLastUserName();
// le meme déroulement qu'en action performed
String Sql = "Select username,password from acteur where username ='" + jTextField1.getText() + "'and password ='" + jPasswordField1.getText() + "'";
con = getConnection("jdbc:mysql://localhost:3306/base_rapport", "root", "");
stmt = con.createStatement();
rs = stmt.executeQuery(Sql);
if (rs.next()) {
//JOptionPane.showMessageDialog(this,"welcome "+jTextField1.getText());
AppPreferences.saveUserName(jTextField1.getText());
p2.setText("welcome " + jTextField1.getText());
nu = jTextField1.getText();
p1.setText("");
Principale s = new Principale();
s.setVisible(true);
this.dispose();
} else {
//JOptionPane.showMessageDialog(this,"invalid username or password");
p1.setText("Invalid user name or password");
}
} catch (SQLException e) {
JOptionPane.showMessageDialog(this, "No data base connection");
}
}
/*Action du bouton QUIT activ avec la touche Enter
Ce bouton permet de fermer la fenetre d'authentification
*/
private void jButton2KeyTyped(java.awt.event.KeyEvent evt) {
// TODO add your handling code here:
System.exit(0);
}
private void jTextField1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
/**
* @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(login.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new login().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JPanel Login;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JPasswordField jPasswordField1;
private javax.swing.JTextField jTextField1;
private javax.swing.JLabel p1;
private javax.swing.JLabel p2;
// End of variables declaration
}
请问有什么问题？
答案 0 :(得分：0)
使用maven构建项目非常简单。在项目的根文件夹中添加pom.xml基本结构。
的pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
</project>
然后从项目的根文件夹中从命令提示符运行命令。
mvn clean install
多数民众赞成你将把你的jar放在模块的/ target文件夹中。
答案 1 :(得分：0)
您似乎是NetBeans和Java的新手。这很简单
1.在NetBeans中的Project Explorer中右键单击您的项目
2.选择属性（最后一个选项）
3.弹出一个窗口，选择运行
4.在您的右手边，点击浏览＆＃34; Main Class：＆＃34;选项。
5.选择您的主要班级
现在，你已经完成了。只需清理并再次构建。