login.java

学生成绩查询系统

package 学生成绩;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;

import 学生成绩.Main;
import 学生成绩.DataBaseManager;

import com.sun.corba.se.pept.transport.Connection;
import java.sql.*;

public class Login extends JFrame {
	DataBaseManager db=new DataBaseManager();
	private JPanel jPanel = null;
	private JLabel jLabel = null;
	private JLabel jLabel1 = null;
	private JLabel jLabel2 = null;
	private JTextField jTextField = null;
	private static JPasswordField jPasswordField = null;
	private JButton jButton = null;
	private JButton jButton1 = null;


	public Login()  {
		super();
		initialize();
	}


	private void initialize() {
        this.setSize(new java.awt.Dimension(432,282));
        try {
			this.setContentPane(getJPanel());
		} catch (Exception e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}
        this.setTitle("学生成绩管理系统");
        this.setVisible(true);

	}

	private JPanel getJPanel()throws Exception {
		if (jPanel == null) {
			jLabel2 = new JLabel();
			jLabel2.setBounds(new java.awt.Rectangle(51,131,54,18));
			jLabel2.setText("密     码:");
			jLabel1 = new JLabel();
			jLabel1.setBounds(new java.awt.Rectangle(51,98,58,19));
			jLabel1.setText("用户名:");
			jLabel = new JLabel();
			jLabel.setBounds(new java.awt.Rectangle(97,15,233,26));
			jLabel.setFont(new java.awt.Font("Dialog", java.awt.Font.BOLD, 18));
			jLabel.setText("欢迎使用学生成绩管理系统 ");
			jPanel = new JPanel();
			jPanel.setLayout(null);
			jPanel.add(jLabel, null);
			jPanel.add(jLabel1, null);
			jPanel.add(jLabel2, null);
			jPanel.add(getJTextField(), null);
			jPanel.add(getJPasswordField(), null);
			jPanel.add(getJButton(), null);
			jPanel.add(getJButton1(), null);
		}
		return jPanel;
	}


	private JTextField getJTextField() {
		if (jTextField == null) {
			jTextField = new JTextField();
			jTextField.setLocation(new java.awt.Point(146,94));
			jTextField.setSize(new java.awt.Dimension(150,30));
		}
		return jTextField;
	}


	private JPasswordField getJPasswordField() {
		if (jPasswordField == null) {
			jPasswordField = new JPasswordField();
			jPasswordField.setLocation(new java.awt.Point(145,131));
			jPasswordField.setSize(new java.awt.Dimension(150,30));
		}
		return jPasswordField;
	}


	private JButton getJButton()throws Exception {
		if (jButton == null) {
			jButton = new JButton();
			jButton.setText("登入");
			jButton.setSize(new java.awt.Dimension(80,25));
			jButton.setLocation(new java.awt.Point(97,175));
			jButton.addActionListener(new java.awt.event.ActionListener() {
				public void actionPerformed(java.awt.event.ActionEvent e)  {
              try {
				in();
			} catch (SQLException e1) {
				// TODO 自动生成 catch 块
				e1.printStackTrace();
			}

				}
			});
		}
		return jButton;
	}


	void close()
	{
		this.dispose();
	}
	private JButton getJButton1() {
		if (jButton1 == null) {
			jButton1 = new JButton();
			jButton1.setText("重置 ");
			jButton1.setSize(new java.awt.Dimension(80,25));
			jButton1.setLocation(new java.awt.Point(234,176));
			jButton1.addActionListener(new java.awt.event.ActionListener() {
				public void actionPerformed(java.awt.event.ActionEvent e) {
					jTextField.setText("");
					jTextField.setText("");
					Main mn=new Main();
					mn.show();
					close();
					
				}
			});
		}
		return jButton1;
	}

	
 void in() throws SQLException{
	//	char[] password=jPasswordField.getPassword();
	//	String passwordSTR=new String(password);
		String strSQL;
		strSQL="select * from login where UserID='"+jTextField.getText().trim()+
		"'and Password='"+jPasswordField.getText().trim()+"'";
		db.res=db.getResult(strSQL);
		
    	if(jTextField.getText().trim().equals(""))
		{
			JOptionPane.showMessageDialog(null,"用户名不可为空!");
			return;
		}
				  if(jPasswordField.getText().trim().equals(""))
		{
			JOptionPane.showMessageDialog(null,"密码不可为空!");
			return;
		}

			if(db.res.first()){
			      Main mn=new Main();
			      mn.show();
			      close();
			    }
			  else{
				  jTextField.setText("卡号或密码错误。");
				  jPasswordField.setText("");
			    }
	}
 public static void main(String[] args)
 {
	 Login lg=new Login();
 }

}