logindialog.java

是适合于使用的管理系统 可以在现实中使用

package mysiloer;

import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import java.sql.Connection;
import java.awt.event.*;
import java.sql.Statement;
import java.sql.SQLException;
import java.sql.ResultSet;

/**
 * <p>Title: MySiloer</p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: yskey</p>
 * @author 杨涛
 * @version 1.0
 */

public class LoginDialog extends JDialog {
  private JPanel panel1 = new JPanel();
  private BorderLayout borderLayout1 = new BorderLayout();
  private JPanel contentPanel = new JPanel();
  private JPanel controlPanel = new JPanel();
  private GridLayout gridLayout1 = new GridLayout();
  private JLabel jLabel1 = new JLabel();
  private JLabel jLabel2 = new JLabel();
  private JTextField userNameField = new JTextField();
  private JPasswordField pwdFiled = new JPasswordField();
  private JButton cancelButt = new JButton();
  private JButton loginButt = new JButton();
  private Border border1;
  private GridLayout gridLayout2 = new GridLayout();
  private Border border2;
  private Connection con = null;
  private boolean isLogin = false;

  public LoginDialog(MainFrame frame, String title, boolean modal) {
    super(frame, title, modal);
    try {
      this.con = frame.dataBase.connection;
      jbInit();
      this.addWindowListener(new WindowAdapter(){
        public void windowClosing(WindowEvent e){
          try{
            con.close();
            System.exit(0);
          }
          catch(SQLException ex){
            System.err.println(ex.toString());
          }
      }});
      this.setResizable(false);
      pack();
      Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
      Dimension frameSize = this.getSize();
      if (frameSize.height > screenSize.height) {
        frameSize.height = screenSize.height;
      }
      if (frameSize.width > screenSize.width) {
        frameSize.width = screenSize.width;
      }
      this.setLocation((screenSize.width - frameSize.width) / 2, (screenSize.height - frameSize.height) / 2);
    }
    catch(Exception ex) {
      ex.printStackTrace();
    }
  }

  public LoginDialog() {
    this(null, "", false);
  }
  private void jbInit() throws Exception {
    border1 = BorderFactory.createEmptyBorder(15,15,15,15);
    border2 = BorderFactory.createEmptyBorder(0,30,10,30);
    panel1.setLayout(borderLayout1);
    contentPanel.setLayout(gridLayout1);
    gridLayout1.setColumns(2);
    gridLayout1.setRows(2);
    gridLayout1.setVgap(5);
    jLabel1.setText("  用户名：");
    jLabel2.setText("  密   码：");
    pwdFiled.setEchoChar('●');
    cancelButt.setText("取   消");
    cancelButt.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        cancelButt_actionPerformed(e);
      }
    });
    loginButt.setText("登   录");
    loginButt.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        loginButt_actionPerformed(e);
      }
    });
    userNameField.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        loginButt_actionPerformed(e);
      }
    });
    pwdFiled.addActionListener(new java.awt.event.ActionListener() {
     public void actionPerformed(ActionEvent e) {
       loginButt_actionPerformed(e);
     }
    });
    contentPanel.setBorder(border1);
    controlPanel.setLayout(gridLayout2);
    gridLayout2.setHgap(40);
    gridLayout2.setVgap(40);
    controlPanel.setBorder(border2);
    userNameField.setText("sa");
    getContentPane().add(panel1);
    panel1.add(contentPanel,  BorderLayout.CENTER);
    panel1.add(controlPanel,  BorderLayout.SOUTH);
    contentPanel.add(jLabel1, null);
    contentPanel.add(userNameField, null);
    contentPanel.add(jLabel2, null);
    contentPanel.add(pwdFiled, null);
    controlPanel.add(loginButt, null);
    controlPanel.add(cancelButt, null);
  }

  void cancelButt_actionPerformed(ActionEvent e) {
    try{
      con.close();
      System.exit(0);
    }
    catch(SQLException ex){
      System.err.println(ex.toString());
    }
  }

  void loginButt_actionPerformed(ActionEvent e) {
    try{
      String password = new String(pwdFiled.getPassword()).trim();
      Statement sta = con.createStatement();
      ResultSet set = sta.executeQuery("select password from userTable where userName like '"+userNameField.getText().trim()+"'");
      if(set != null){
        set.next();
        String pwd = set.getString(1);
        pwd = pwd.trim();
        if(pwd.equals(password)){
          System.out.println(password);
          setLogin(true);
          this.setVisible(false);
          this.dispose();
        }
        else{
          JOptionPane.showMessageDialog(this, "您输入的密码不正确，请重新输入！！");
        }
      }
    }
    catch(SQLException ex){
      System.err.println(ex.toString());
      JOptionPane.showMessageDialog(this, "您输入的用户名不存在，请重新输入！！");
    }
  }
  private void setLogin(boolean isLogin){
    this.isLogin = isLogin;
  }
  public boolean getLogin(){
    return this.isLogin;
  }
}