userlogin.java

这是一个用JAVA编写的书籍借阅管理系统

package bookmanager;

import java.awt.*;
import javax.swing.*;
import com.borland.jbcl.layout.*;
import java.awt.event.*;
import java.sql.*;

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2003</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 1.0
 */

public class userLogin
    extends JDialog {
  //定义结果集
  ResultSet rs;
  //定义数据库操作对象
  private DBManager db = new DBManager();
  //定义主窗口类，用于操作父窗体
  BookManagerMain myMain;

  JPanel panel1 = new JPanel();
  XYLayout xYLayout1 = new XYLayout();
  XYLayout xYLayout2 = new XYLayout();
  JLabel jLabel1 = new JLabel();
  JLabel jLabel2 = new JLabel();
  JTextField jTextFieldusername = new JTextField();
  JButton jButtonOK = new JButton();
  JButton jButtonCancel = new JButton();
  JPasswordField jPasswordold = new JPasswordField();
  //缺省构造方法
  public userLogin(Frame frame, String title, boolean modal) {
    super(frame, title, modal);
    try {
      jbInit();
      pack();
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
  }

  //缺省构造方法
  public userLogin() {
    this(null, "", false);
  }

  //定义可传递父类的构造方法
  public userLogin(BookManagerMain bMain) {
    this(null, "", false);
    myMain = bMain;
  }

  //初始化对象
  private void jbInit() throws Exception {
    panel1.setLayout(xYLayout2);
    this.getContentPane().setLayout(xYLayout1);
    jLabel1.setFont(new java.awt.Font("Dialog", 0, 16));
    jLabel1.setText("用户名");
    jLabel2.setFont(new java.awt.Font("Dialog", 0, 16));
    jLabel2.setText("密码");
    jTextFieldusername.setFont(new java.awt.Font("Dialog", 0, 16));
    jTextFieldusername.setText("");
    jButtonOK.setFont(new java.awt.Font("Dialog", 0, 16));
    jButtonOK.setText("确定");
    jButtonOK.addMouseListener(new userLogin_jButtonOK_mouseAdapter(this));
    jButtonCancel.setFont(new java.awt.Font("Dialog", 0, 16));
    jButtonCancel.setText("取消");
    jButtonCancel.addMouseListener(new userLogin_jButtonCancel_mouseAdapter(this));
    jPasswordold.setText("");
    xYLayout1.setWidth(400);
    xYLayout1.setHeight(271);
    this.setResizable(true);
    this.setTitle("用户登录");
    panel1.add(jTextFieldusername, new XYConstraints(210, 49, 111, 38));
    panel1.add(jPasswordold, new XYConstraints(211, 112, 111, 35));
    panel1.add(jLabel1, new XYConstraints(59, 50, 99, 34));
    panel1.add(jLabel2, new XYConstraints(60, 116, 80, 34));
    panel1.add(jButtonCancel, new XYConstraints(212, 209, 94, 30));
    panel1.add(jButtonOK, new XYConstraints(94, 208, 91, 31));
    this.getContentPane().add(panel1, new XYConstraints( -2, 0, 400, 272));
  }
 //若用户直接按取消，则取消用户权限
  void jButtonCancel_mouseClicked(MouseEvent e) {
       myMain.setEnable("else");
       this.dispose();
  }

  void jButtonOK_mouseClicked(MouseEvent e) {
    //校验用户名是否为空
    if (jTextFieldusername.getText().trim().equals("")) {
      JOptionPane.showMessageDialog(null, "用户名不可为空！");
      return;
    }
    //校验密码是否为空
    if (jPasswordold.getText().trim().equals("")) {
      JOptionPane.showMessageDialog(null, "密码不可为空！");
      return;
    }
    String strSQL;
    //生成sql操作语句，查询要登陆的用户名是否存在，若存在执行下一步操作，若不存在提示并返回
    strSQL = "select * from user where Username='" +
        jTextFieldusername.getText().trim() + "' and Password='" +
        jPasswordold.getText().trim() + "'";
    rs = db.getResult(strSQL);
    boolean isexist = false;
    try {
      isexist = rs.first();
    }
    catch (SQLException ex1) {
    }
    //若用户名不存在，提示警告信息
    if (!isexist) {
      JOptionPane.showMessageDialog(null, "用户名不存在，或密码不正确！");
      myMain.setEnable("else");
    }
    //  若用户名存在，设置权限
    else {
      try {
        rs.first();
        myMain.setEnable(rs.getString("Power").trim());
        this.dispose();
      }
      catch (SQLException ex) {
      }

    }
  }
}

class userLogin_jButtonCancel_mouseAdapter
    extends java.awt.event.MouseAdapter {
  userLogin adaptee;

  userLogin_jButtonCancel_mouseAdapter(userLogin adaptee) {
    this.adaptee = adaptee;
  }

  public void mouseClicked(MouseEvent e) {
    adaptee.jButtonCancel_mouseClicked(e);
  }
}

class userLogin_jButtonOK_mouseAdapter
    extends java.awt.event.MouseAdapter {
  userLogin adaptee;
  userLogin_jButtonOK_mouseAdapter(userLogin adaptee) {
    this.adaptee = adaptee;
  }

  public void mouseClicked(MouseEvent e) {
    adaptee.jButtonOK_mouseClicked(e);
  }
}