Question

求Java编的登录界面代码：登录后分别进入管理员界面及用户界面，依据是数据库中的用户名和密码

用户名符合管理员表中的Gno，就进入管理员界面，符合用户表中的Uno，就进入用户界面

Answer 1

分三个包，自己建个包，导进去就ok了，数据库是access的。
package 登录;

import java.awt.EventQueue;

public class Cilent {

private JFrame frame;
private JTextField textField;
private JPasswordField passwordField;

/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Cilent window = new Cilent();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}

/**
* Create the application.
*/
public Cilent() {
initialize();
}

/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setTitle("登陆界面");
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
frame.setResizable(false);

JLabel lblNewLabel = new JLabel("用户名");
lblNewLabel.setBounds(38, 43, 80, 34);
frame.getContentPane().add(lblNewLabel);

textField = new JTextField();
textField.setBounds(155, 42, 227, 37);
frame.getContentPane().add(textField);
textField.setColumns(10);

JLabel label = new JLabel("密　码");
label.setBounds(38, 115, 80, 34);
frame.getContentPane().add(label);

passwordField = new JPasswordField();
passwordField.setBounds(155, 115, 227, 37);
frame.getContentPane().add(passwordField);

JButton btnNewButton = new JButton("登　录");
btnNewButton.setBounds(60, 187, 115, 34);
frame.getContentPane().add(btnNewButton);
btnNewButton.addActionListener(new ActionListener() {

@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
UserCheck UC=new UserCheck(textField.getText(),String.valueOf(passwordField.getPassword()));
if(UC.getI()!=0) //有此用户
{
frame.setVisible(false);
}
else
{
textField.setText("");
passwordField.setText("");
}
}
});

JButton button = new JButton("取　消");
button.setBounds(242, 187, 115, 34);
frame.getContentPane().add(button);
button.addActionListener(new ActionListener() {

@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
textField.setText("");
passwordField.setText("");
}
});
}
}
/*****************************************************************/
package 登录;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import 操作处理.UsersCL;

/**@author 20111024
* 检测登录的用户在数据库中有无，若没有，则提示没有此用户，
* 若有，则判断级别：普通用户还是管理员。
*/
public class UserCheck {

private int i=0; //用户级别:0不是用户、1是管理员、2是普通用户
UserCheck(String name ,String password)
{
String jdriver="sun.jdbc.odbc.JdbcOdbcDriver";
String connectDB="jdbc:odbc:Students";
Statement stmt=null;
ResultSet rs=null;
Connection con=null;
try {
Class.forName(jdriver);
con=DriverManager.getConnection(connectDB);
stmt=con.createStatement();
String query="select * from users where name='"+name+"' and passwd='"+password+"'";

rs=stmt.executeQuery(query);
if(rs.next())
{
//数据库中有此用户，访问成功
i=Integer.parseInt(rs.getString(3));
UsersCL UL=new UsersCL(i);
}
else
{
i=0; //没有用户是默认是0级
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public int getI() {
return i;
}
}
/********************************************************************************************/
package 操作处理;

import java.awt.EventQueue;

public class UsersCL implements ActionListener{

private JFrame frame;
private JTextField textField;
private JTextField textField_1;
private JTextField textField_2;
private JTextField textField_3;
private int i=0;
private JLabel label_3;
private JTextField textField_4;
public UsersCL(int i) {
this.i=i;
frame = new JFrame();
frame.setTitle("用户处理界面");
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
frame.setResizable(false);
frame.setVisible(true);

JLabel lblNewLabel = new JLabel("学　号");
lblNewLabel.setBounds(24, 32, 74, 29);
frame.getContentPane().add(lblNewLabel);

JLabel label = new JLabel("姓　名");
label.setBounds(24, 71, 74, 29);
frame.getContentPane().add(label);

JLabel label_1 = new JLabel("年　龄");
label_1.setBounds(24, 110, 74, 29);
frame.getContentPane().add(label_1);

label_3 = new JLabel("性　别");
label_3.setBounds(24, 149, 74, 29);
frame.getContentPane().add(label_3);

JLabel label_2 = new JLabel("状　态");
label_2.setBounds(24, 195, 74, 29);
frame.getContentPane().add(label_2);

textField = new JTextField();
textField.setBounds(101, 34, 113, 25);
frame.getContentPane().add(textField);
textField.setColumns(10);

textField_1 = new JTextField();
textField_1.setColumns(10);
textField_1.setBounds(101, 73, 113, 25);
frame.getContentPane().add(textField_1);

textField_2 = new JTextField();
textField_2.setColumns(10);
textField_2.setBounds(101, 112, 113, 25);
frame.getContentPane().add(textField_2);

textField_3 = new JTextField();
textField_3.setEditable(false);
textField_3.setColumns(10);
textField_3.setBounds(101, 199, 288, 25);
frame.getContentPane().add(textField_3);

textField_4 = new JTextField();
textField_4.setColumns(10);
textField_4.setBounds(101, 149, 113, 25);
frame.getContentPane().add(textField_4);

if(1==i)
{
JButton btnNewButton = new JButton("追　加");
btnNewButton.setBounds(276, 41, 113, 29);
frame.getContentPane().add(btnNewButton);
btnNewButton.addActionListener(this);
btnNewButton.setActionCommand("追加");

JButton button_1 = new JButton("删　除");
button_1.setBounds(276, 145, 113, 29);
frame.getContentPane().add(button_1);
button_1.addActionListener(this);
button_1.setActionCommand("删除");
}

JButton button = new JButton("查　询");
button.setBounds(276, 91, 113, 29);
frame.getContentPane().add(button);
button.addActionListener(this);
button.setActionCommand("查询");
}
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
String name,age,sex,query=null;
int num,age1,count=0;
num=Integer.parseInt(textField.getText());
name=textField_1.getText();
age1=Integer.parseInt(textField_2.getText());
sex=textField_4.getText();

if(e.getActionCommand().equals("追加"))
{
query="insert into students values("+num+","+"'"+name+"',"+age1+",'"+sex+"');";
count=1;
}
else if(e.getActionCommand().equals("查询"))
{
query="select * from students where XSB="+num+";";
count=2;
}
else if(e.getActionCommand().equals("删除"))
{
query="delete from students where XSB="+num+" and name="+"'"+name+"'";
count=3;
}

Statement stmt=null;
ResultSet rs=null;
Connection con=null;
String jdriver="sun.jdbc.odbc.JdbcOdbcDriver";
String connectDB="jdbc:odbc:Students";
String query1=null;
try {
Class.forName(jdriver);
con=DriverManager.getConnection(connectDB);
stmt=con.createStatement();
if(count==1)
{
query1="select * from students where XSB="+num+";";
rs=stmt.executeQuery(query1);
if(rs.next())
textField_3.setText("已经由此记录，不能追加！");
else
{
stmt.executeUpdate(query);
textField_3.setText("已经追加完成！");
}
}
else if(2==count)
{
stmt.executeQuery(query);
rs=stmt.executeQuery(query);
if(rs.next())
{
textField_3.setText("已查找到此记录！");
}
else
{
textField_3.setText("没有此记录，可以追加！");
}
}
else if(3==count)
{
query1="select * from students where XSB="+num+" and name="+"'"+name+"'";
rs=stmt.executeQuery(query1);
if(rs.next())
{
stmt.executeUpdate(query);
textField_3.setText("已删除此记录！");
}
else
textField_3.setText("无此记录！");
}
} catch (ClassNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
finally{
//关闭资源
if(stmt!=null){
try {
stmt.close();
} catch (Exception e2) {
// TODO: handle exception
}
stmt=null;
}
if(con!=null){
try {
con.close();
} catch (Exception e2) {
// TODO: handle exception
}
con=null;
}
}
}
}