userlogin.java

用java写的一个图书馆管理系统,应该说功能相当全面.包含所有源代码,从数据库的建立到客户端.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;

public class UserLogin
    extends JFrame
    implements ActionListener {
  DataBaseManager db = new DataBaseManager();
  MainFrame mainFrame;
  JPanel panel1, panel2;
  JLabel userLabel, passwordLabel;
  JTextField userTextField;
  JPasswordField passwordTextField;
  JButton yesBtn, cancelBtn;
  Container c;
  ResultSet rs;
  public UserLogin(MainFrame mainFrame) {
    super("用户登录");
    this.mainFrame = mainFrame;
    userLabel = new JLabel("用户名", JLabel.CENTER);
    passwordLabel = new JLabel("密码", JLabel.CENTER);
    userTextField = new JTextField(10);
    passwordTextField = new JPasswordField(10);
    yesBtn = new JButton("确定");
    cancelBtn = new JButton("取消");
    yesBtn.addActionListener(this);
    cancelBtn.addActionListener(this);
    panel1 = new JPanel();
    panel1.setLayout(new GridLayout(2, 2));
    panel2 = new JPanel();
    c = getContentPane();
    c.setLayout(new BorderLayout());
    panel1.add(userLabel);
    panel1.add(userTextField);
    panel1.add(passwordLabel);
    panel1.add(passwordTextField);
    c.add(panel1, BorderLayout.CENTER);
    panel2.add(yesBtn);
    panel2.add(cancelBtn);
    c.add(panel2, BorderLayout.SOUTH);
    setSize(300, 300);
  }

  public void actionPerformed(ActionEvent e) {
    if (e.getSource() == cancelBtn) {
      mainFrame.setEnable("else");
      this.dispose();
    }
    else {
      char[] password = passwordTextField.getPassword();
      String passwordSTR = new String(password);
      if (userTextField.getText().trim().equals("")) {
        JOptionPane.showMessageDialog(null, "用户名不可为空!");
        return;
      }
      if (passwordSTR.equals("")) {
        JOptionPane.showMessageDialog(null, "密码不可为空!");
        return;
      }
      String strSQL;
      strSQL = "select * from usertable where UserName='" +
          userTextField.getText().trim() + "'and Password='" +
          passwordSTR + "'";
      rs = db.getResult(strSQL);
      boolean isExist = false;
      try {
        isExist = rs.first();
      }
      catch (SQLException sqle) {
        System.out.println(sqle.toString());
      }
      if (!isExist) {
        JOptionPane.showMessageDialog(null, "用户名不存在或者密码不正确!");
        mainFrame.setEnable("else");
      }
      else {
        try {
          rs.first();
          mainFrame.setEnable(rs.getString("power").trim());
          db.closeConnection();
          this.dispose();
        }
        catch (SQLException sqle2) {
          System.out.println(sqle2.toString());
        }
      }

    }
  }
}