import java.awt.*
import javax.swing.*
import java.awt.event.*
import java.sql.*
class LoginFrm extends JFrame implements ActionListener// throws Exception
{
JLabel lbl1 = new JLabel("用户名:")
JLabel lbl2 = new JLabel("密码:")
JTextField txt = new JTextField(5)
JPasswordField pf = new JPasswordField()
JButton btn1 = new JButton("确定")
JButton btn2 = new JButton("取消")
public LoginFrm() {
this.setTitle("登陆")
JPanel jp = (JPanel) this.getContentPane()
jp.setLayout(new GridLayout(3, 2, 5, 5))
jp.add(lbl1)
jp.add(txt)
jp.add(lbl2)
jp.add(pf)
jp.add(btn1)
jp.add(btn2)
btn1.addActionListener(this)
btn2.addActionListener(this)
}
public void actionPerformed(ActionEvent ae) {
if (ae.getSource() == btn1) {
try {
Class.forName("com.mysql.jdbc.Driver")// mysql数据库
Connection con = DriverManager.getConnection(
"jdbc:mysql://localhost/Car_zl", "root", "1")// 数据库名为Car_zl，密码为1
System.out.println("com : "+ con)
Statement cmd = con.createStatement()
String sql = "select * from user where User_ID='"
+ txt.getText() + "' and User_ps='"
+ pf.getText() + "'"
ResultSet rs = cmd
.executeQuery(sql)// 表名为user，user_ID和User_ps是存放用户名和密码的字段名
if (rs.next()) {
JOptionPane.showMessageDialog(null, "登陆成功！")
} else
JOptionPane.showMessageDialog(null, "用户名或密码错误！")
} catch (Exception ex) {
}
if (ae.getSource() == btn2) {
System.out.println("1111111111111")
//txt.setText("")
//pf.setText("")
System.exit(0)
}
}
}
public static void main(String arg[]) {
JFrame.setDefaultLookAndFeelDecorated(true)
LoginFrm frm = new LoginFrm()
frm.setSize(400, 200)
frm.setVisible(true)
}
}
java的用户登录记住上次登录的用户名和密码的方式是使用cookie来保存在本地，并且需要加密保存，实例如下：
HttpServletRequest request = ServletActionContext.getRequest()Cookie cookies[]=request.getCookies()//声明一个cookie对象
String login=null//登录的用户名
String password=null //登录的密码
for (int i = 0 i < cookies.length i++){ //取最后一次保存的用户名和密码
if(cookies[i].getName().equals("userName")){
login = cookies[i].getValue()
}
if (cookies[i].getName().equals("password")){
password = cookies[i].getValue()
break
}
}
if(!AssertUtil.isEmpty(login)&&!login.equals("JSESSIONID")){
request.setAttribute("login", login)
request.setAttribute("password", password)
}
