使用java swing将数据库存储到数组中

时间：2015-04-02 22:06:58

标签： arrays database swing ms-access

我有两个窗户。一个登录窗口（称为main;我还在测试）和一个MainWindow。我正在从MS Access数据库中读取登录数据（用户名，密码）。该数据库有四个表，Customer，Accounts，Mortgage，CreditCard。到目前为止，一切正常，但是当我们成功登录时，我正试图将用户的名字和姓氏传递给主窗口中的JLabel。我该怎么做呢？用户登录后是否需要customerindex？在我可以在帧之间传递之前，是否需要将其存储在数组中？如果是这样，我该怎么做？我还在学习，所以一个例子会很棒。

我假设我的数组看起来像这样？

Account accounts[] = new Account[2];
Customer people[] = new Customer[2];
CreditCard credit[] = new CreditCard[2];
Mortgage mortgage[] = new Mortgage[2];
int index = 0;

这是我的登录类

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

public class Login extends JFrame
{
Connection con;
Statement st;
ResultSet rs;

JFrame f = new JFrame("User Login");
JLabel l = new JLabel("Username");
JLabel l1 = new JLabel("Password");
JTextField t = new JTextField(10);
JTextField t1 = new JTextField(10);
JButton b = new JButton("Login");

public Login()
{
    connect();
    frame();

}

public void connect()
{
    try
    {

        //Connect to the database
        con = DriverManager.getConnection("jdbc:ucanaccess://G:/JSProject/prjTIMS_JS/Bank.mdb");
        st = con.createStatement();
        System.out.println("Connected database successfully ...");
    }
    catch(Exception ex)
    {
    }
}

public void frame()
{
    f.setSize(600,100);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);

    JPanel p = new JPanel();
    p.add(l);
    p.add(t);
    p.add(l1);
    p.add(t1);
    p.add(b);

    f.add(p);

    b.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent e)
        {
            try
            {
            String username = t.getText().trim();
            String password = t1.getText().trim();

            String sql = "select username, password from tblCustomer where username = '" +username+"'and password = '"+password+"'" ;
            rs = st.executeQuery(sql);

            int count = 0;
            while(rs.next())
            {
                count ++;
            }

            if(count == 1)
            {
                setVisible(false);
                new MainWindow();
            }
            else if(count > 1)
            {
                JOptionPane.showMessageDialog(null, "Duplicate User, Access Denied!");
            }
            else
            {
                JOptionPane.showMessageDialog(null, "User Not Found!");
            }




            }

            catch(Exception ex)
            {
               JOptionPane.showMessageDialog(null, "Catch Error");         
            }
        }
    });
}   

public static void main(String[] args) {

    new Login();

}}

主窗口

import java.awt.*;
import java.awt.event.KeyEvent;

import javax.swing.*;


public class MainWindow extends JFrame {

MainWindow() {
    //Create a new frame container
    setTitle("Jo's Dealership: Main Menu");


    //Give the frame an initial size and center the window
    setSize(390, 270);
    setLocationRelativeTo(null);

    //Terminate the program when the user closes the application
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    ImageIcon image = new ImageIcon("pc.png");
    JLabel lblImage = new JLabel(image);
    lblImage.setPreferredSize(new Dimension(48, 48));

    JLabel lblOptionMsg = new JLabel(" choose an option below.");
    lblOptionMsg.setFont(new Font("Helvetica", Font.PLAIN, 11));
    lblOptionMsg.setForeground(new Color(37, 75, 124));

     //Make two buttons
    JButton okButton = new JButton ("OK"); 
    okButton.setFont(new Font("Helvetica", Font.BOLD, 12));
    okButton.setOpaque(false);
    okButton.setPreferredSize(new Dimension(85, 22));
    okButton.setForeground(new Color(37, 75, 124));

    JButton cancelButton = new JButton ("Logout");  
    cancelButton.setFont(new Font("Helvetica", Font.BOLD, 12));
    cancelButton.setOpaque(false);
    cancelButton.setPreferredSize(new Dimension(85, 22));
    cancelButton.setForeground(new Color(37, 75, 124));

     JRadioButton buyButton = new JRadioButton("Buy Car", true);
     buyButton.setMnemonic(KeyEvent.VK_B);
     buyButton.setActionCommand("Buy");
     buyButton.setFont(new Font("Helvetica", Font.BOLD, 11));
     buyButton.setOpaque(true);
     buyButton.setPreferredSize(new Dimension(120, 22));
     buyButton.setForeground(new Color(37, 75, 124));

     JRadioButton calcButton = new JRadioButton("Calculate Commission", true);
     calcButton.setMnemonic(KeyEvent.VK_C);
     calcButton.setActionCommand("Calculate");
     calcButton.setFont(new Font("Helvetica", Font.BOLD, 11));
     calcButton.setOpaque(true);
     calcButton.setPreferredSize(new Dimension(200, 22));
     calcButton.setForeground(new Color(37, 75, 124));

     ButtonGroup bG = new ButtonGroup();
     bG.add(buyButton);
     bG.add(calcButton);
     buyButton.setSize(100,200);
     calcButton.setSize(100,200);

    //Create text based label
    JLabel lblMessage = new JLabel("[CustomerNameHere] is currently logged on.");
    lblMessage.setFont(new Font("Helvetica", Font.PLAIN, 11));
    lblMessage.setForeground(new Color(37, 75, 124));

    //Add the panel to the content page
    JPanel panel = new JPanel();
    add(panel);
    panel.setBackground(new Color(239, 239, 239));

    //Display the frame
    setVisible(true);

    //Set the layout
    SpringLayout layout = new SpringLayout();
    panel.setLayout(layout);

    //Add the label to the content pane
    panel.add(lblImage);
    panel.add(lblMessage);
    panel.add(lblOptionMsg);
    panel.add(okButton);
    panel.add(cancelButton);
    panel.add(buyButton);
    panel.add(calcButton);

    //Adjust constraints for the components
    layout.putConstraint(SpringLayout.WEST, lblImage, 150,  SpringLayout.WEST, panel);
    layout.putConstraint(SpringLayout.NORTH, lblImage, 50, SpringLayout.NORTH, panel);
    layout.putConstraint(SpringLayout.WEST, lblMessage, 75, SpringLayout.WEST, panel);  //right
    layout.putConstraint(SpringLayout.NORTH, lblMessage, 10, SpringLayout.NORTH, panel);  //top
    layout.putConstraint(SpringLayout.WEST, okButton, 90, SpringLayout.WEST, panel);
    layout.putConstraint(SpringLayout.NORTH, okButton, 185, SpringLayout.NORTH, panel);
    layout.putConstraint(SpringLayout.WEST, cancelButton, 195,  SpringLayout.WEST, panel);
    layout.putConstraint(SpringLayout.NORTH, cancelButton, 185, SpringLayout.NORTH, panel);
    layout.putConstraint(SpringLayout.WEST, buyButton, 95,  SpringLayout.WEST, panel);
    layout.putConstraint(SpringLayout.NORTH, buyButton, 105, SpringLayout.NORTH, panel);
    layout.putConstraint(SpringLayout.WEST, calcButton, 95,  SpringLayout.WEST, panel);
    layout.putConstraint(SpringLayout.NORTH, calcButton, 135, SpringLayout.NORTH, panel);
    layout.putConstraint(SpringLayout.WEST, lblOptionMsg, 105,  SpringLayout.WEST, panel);
    layout.putConstraint(SpringLayout.NORTH, lblOptionMsg, 25, SpringLayout.NORTH, panel);
}

public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    SwingUtilities.invokeLater(new Runnable() {

        @Override 
        public void run() {
            //new MainWindow(0).setVisible(true);
        }
    });
}
}

1 个答案:

答案 0 :(得分：0)

如果您想将登录用户的名字和姓氏传递给MainWindow，这是一种简单的方法。

首先，在验证数据库中是否存在用户时，修改您的查询以获取Last和First名称：

String sql = "select FName, LName from tblCustomer where username = '" +username+"'and password = '"+password+"'" ;
rs = st.executeQuery(sql);

int count = 0;
String lastName ='';
String firstName = '';
while(rs.next())
{
  count ++;
  //get last name and first name when connected
  lastName = rs.getString("LName");
  firstName = rs.getString("FName");
}

然后：

if(count == 1)
 {
   setVisible(false);
   new MainWindow( firstName+" "+lastName);//<--pass it here to the mainWindow
 }

最后，在您的MainWindow中：

public class MainWindow extends JFrame {
    private String whosLoggedOn;
    MainWindow(String whosLoggedOn) {
         this.whosLoggedOn = whosLoggedOn;

         //------ other stuff--------

         //Create text based label
         JLabel lblMessage = new JLabel(this.whosLoggedOnis+ " is currently logged on.");
        //------ other stuff--------

  }
  }

编辑1： 如果要传递其他表中的其他信息，例如tblCustomer和tblAccount，可以像这样修改MainWindow的构造函数：

  public class MainWindow extends JFrame {
    MainWindow(ResultSet tblCustomer, ResultSet tblAccount ) {


         //use them as you want here
         //for example to get last and first name :
          String lastName = tblCustomer.getString("LName");
          String firstName = tblCustomer.getString("FName");

         //Create text based label
         JLabel lblMessage = new JLabel(lastName +" "+ firstName" is currently logged on.");
        //------ other stuff--------

  }
  }

现在，在您的登录信息JFrame中，您只需查询所需的表格，并在连接后将ResultSet传递给mainWindow。

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