loginjframe.java

一个简单的登陆程序

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * LogInJFrame.java
 *
 * Created on 2009-4-1, 19:57:41
 */

package logintest;

import java.util.logging.Level;
import java.util.logging.Logger;
import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.swing.JOptionPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

/**
 *
 * @author Administrator
 */
public class LogInJFrame extends javax.swing.JFrame {

    /** Creates new form LogInJFrame */
    private EntityManager em = LogInPersistence.getEm();
    public LogInJFrame() {
        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(LogInJFrame.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            Logger.getLogger(LogInJFrame.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            Logger.getLogger(LogInJFrame.class.getName()).log(Level.SEVERE, null, ex);
        } catch (UnsupportedLookAndFeelException ex) {
            Logger.getLogger(LogInJFrame.class.getName()).log(Level.SEVERE, null, ex);
        }
        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">//GEN-BEGIN:initComponents
    private void initComponents() {

        jLabel3 = new javax.swing.JLabel();
        jButton3 = new javax.swing.JButton();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        namejTextField = new javax.swing.JTextField();
        passwordjPasswordField = new javax.swing.JPasswordField();
        logInjButton = new javax.swing.JButton();
        quitjButton = new javax.swing.JButton();

        jLabel3.setText("jLabel3");

        jButton3.setText("jButton3");

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jLabel1.setText("用户姓名");

        jLabel2.setText("用户密码");

        passwordjPasswordField.setEchoChar('#');

        logInjButton.setText("登   录");
        logInjButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                logInjButtonActionPerformed(evt);
            }
        });

        quitjButton.setText("退   出");
        quitjButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                quitjButtonActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addGap(19, 19, 19)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                    .addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
                        .addComponent(logInjButton)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(quitjButton))
                    .addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
                        .addComponent(jLabel2)
                        .addGap(18, 18, 18)
                        .addComponent(passwordjPasswordField))
                    .addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
                        .addComponent(jLabel1)
                        .addGap(18, 18, 18)
                        .addComponent(namejTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 206, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap(28, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel1)
                    .addComponent(namejTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(33, 33, 33)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2)
                    .addComponent(passwordjPasswordField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(logInjButton)
                    .addComponent(quitjButton))
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>//GEN-END:initComponents

    private void quitjButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_quitjButtonActionPerformed
        // TODO add your handling code here:
       int result = JOptionPane.showConfirmDialog(this, "您确实要退出系统？", "提示", JOptionPane.YES_NO_OPTION);
        if (result == JOptionPane.YES_OPTION) {
            System.exit(0);
        }
    }//GEN-LAST:event_quitjButtonActionPerformed

    private void logInjButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_logInjButtonActionPerformed
        // TODO add your handling code here:
        boolean flag=true;
        boolean check;
        People user = null;
        String name=namejTextField.getText();
        String password=String.copyValueOf(passwordjPasswordField.getPassword());
        
        if(name.equals("")||password.equals("")){
            flag =false;
            JOptionPane.showMessageDialog(this, "用户名或密码不能为空！", "登录失败", JOptionPane.INFORMATION_MESSAGE);
        }else if(flag=true){
            try {
                user = (People) em.createQuery("select user from People as user where user.name= '" + namejTextField.getText() + "'"+"and user.password='"+password+"'").getSingleResult();
            } catch (NoResultException e) {
                check = false;
                JOptionPane.showMessageDialog(this, "该用户不存在或者密码输入有误!", "登录失败", JOptionPane.INFORMATION_MESSAGE);
                return;
            }
            if(check=true){
                JOptionPane.showMessageDialog(this, "登录系统成功！", "提示", JOptionPane.INFORMATION_MESSAGE);
            } 
        }

    }//GEN-LAST:event_logInjButtonActionPerformed

    /**
    * @param args the command line arguments
    */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new LogInJFrame().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton jButton3;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JButton logInjButton;
    private javax.swing.JTextField namejTextField;
    private javax.swing.JPasswordField passwordjPasswordField;
    private javax.swing.JButton quitjButton;
    // End of variables declaration//GEN-END:variables

}