String sql = "select username,password from account"
String user = request.getParameter("user")
String pass = request.getParameter("password")
int j = 0
Connection conn = null
PreparedStatement ps = null
ResultSet rs = null
try {
conn = JDBCTools1.getConnection()
ps = conn.prepareStatement(sql)
rs = ps.executeQuery()
//从表中查询获取所有账户的用户名&密码的ResultSet 对象
while(rs.next()){
int i = 0
String username[] = new String[10]//用户名数组
String password[] = new String[10]//密码数组
username[i] = rs.getString(1)
password[i] = rs.getString(2)
if(user.equals(username[i])&&pass.equals(password[i])){//比对
response.getWriter().print("you are welcome!")
j++
}else if(user.equals(username[i])&&!pass.equals(password[i])){
response.getWriter().println("the realy password is :"+ username[i] +","+password[i]+"\r\n")
response.getWriter().println("and you password is :"+user +","+pass+" :so the username or password may not right")
j++
}else{
continue
}
i++
}
if(j == 0){
response.getWriter().println("Your username may not be properly")
}
} catch (Exception e) {
e.printStackTrace()
}finally{
JDBCTools1.release(rs, ps, conn)
}
//这是我JDBCTools的getConnection方法
getConnection{
String driverClass = oracle.jdbc.driver.OracleDriver
String jdbcUrl = jdbc:oracle:thin:@localhost:1521:orcl
//你的数据库的用户名密码
String user = null
String password = null
// 通过反射创建Driver对象
Class.forName(driverClass)
return DriverManager.getConnection(jdbcUrl, user, password)}
//这是我JDBCTools的release方法
public static void release(ResultSet rs, Statement statement,
Connection conn) {
if (rs != null) {
try {
rs.close()
} catch (SQLException e) {
e.printStackTrace()
}
}
if (statement != null) {
try {
statement.close()
} catch (Exception e2) {
e2.printStackTrace()
}
}
if (conn != null) {
try {
conn.close()
} catch (Exception e2) {
e2.printStackTrace()
}
}
}
这是我以前写的系统登录框的loginpackage java1
import java.awt.*
import java.awt.event.*
import java.sql.*
import java.util.*
import javax.swing.*
import javax.swing.event.*
import java.awt.Rectangle
import java.awt.Font
public class login extends JFrame
{
public login() {
try {
jbInit()
}
catch (Exception ex) {
ex.printStackTrace()
}
}
public static void main(String[] args)
{
login frm=new login()
frm.setBounds(300,200,300,260)
frm.setVisible(true)
}
private void jbInit() throws Exception {
this.getContentPane().setLayout(null)
jLabel1.setForeground(Color.red)
jLabel1.setText("用户名")
jLabel1.setBounds(new Rectangle(25, 72, 68, 29))
jButton2.setBounds(new Rectangle(142, 159, 81, 30))
jButton2.setText("取消")
jButton2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
jButton2_actionPerformed(e)
}
})
jButton1.setBounds(new Rectangle(38, 159, 81, 29))
jButton1.setText("确定")
jButton1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
jButton1_actionPerformed(e)
}
})
jTextField1.setBounds(new Rectangle(109, 79, 136, 23))
jPasswordField1.setBounds(new Rectangle(109, 115, 136, 23))
this.getContentPane().add(jLabel1)
jLabel3.setFont(new java.awt.Font("隶书", Font.PLAIN, 24))
jLabel3.setText("学 生 考 试 系 统")
jLabel3.setBounds(new Rectangle(22, 15, 268, 47))
this.getContentPane().add(jTextField1)
this.getContentPane().add(jLabel2)
this.getContentPane().add(jButton2)
this.getContentPane().add(jButton1)
this.getContentPane().add(jLabel3)
this.getContentPane().add(jPasswordField1)
jLabel2.setForeground(Color.red)
jLabel2.setText("密码")
jLabel2.setBounds(new Rectangle(26, 112, 68, 29))
}
JLabel jLabel1 = new JLabel()
JLabel jLabel2 = new JLabel()
JTextField jTextField1 = new JTextField()
JButton jButton1 = new JButton()
JButton jButton2 = new JButton()
JLabel jLabel3 = new JLabel()
JPasswordField jPasswordField1 = new JPasswordField()
main2 wo=new main2()
int sum
//判断权限的方法
public void success()
{
try{
ResultSet rs1
String s1="select * from 管理权限 where name='"+jTextField1.getText()+"' and password='"+jPasswordField1.getText()+"'"
rs1=sqlcx.Rs_jiluji(s1)
rs1.first()
sum=Integer.parseInt((String)(rs1.getString(3)))
System.out.println(sum)
very()
}
catch(Exception c){System.out.println("success error")}
}
//根据权限设置窗口
public void very()
{
if (sum==1)
{JOptionPane.showOptionDialog(this, "您现在是以教师权限登陆", "登陆信息"
, JOptionPane.DEFAULT_OPTION,
JOptionPane.ERROR_MESSAGE,
null, null, null)
}
else
{
JOptionPane.showOptionDialog(this, "你现在是以学生权限登陆", "登陆信息"
, JOptionPane.DEFAULT_OPTION,
JOptionPane.ERROR_MESSAGE,
null, null, null)
wo.jButton2.setVisible(false)
wo.jButton3.setVisible(false)
wo.jButton4.setVisible(false)
wo.jButton5.setVisible(false)
wo.jButton6.setVisible(false)
wo.jButton7.setVisible(false)
wo.jButton8.setVisible(false)
wo.jMenu2.setVisible(false)
wo.jMenu3.setVisible(false)
wo.jMenu4.setVisible(false)
}
}
public void jButton1_actionPerformed(ActionEvent e)
{
//判断用户名是否为空
if (jTextField1.getText().length() == 0) {
JOptionPane.showOptionDialog(this, "用户名不能为空", "错误信息"
, JOptionPane.DEFAULT_OPTION,
JOptionPane.ERROR_MESSAGE,
null, null, null)
}
//判断密码是否为空
else if (jPasswordField1.getText().length()==0)
{
JOptionPane.showOptionDialog(this,"密码不能为空", "错误信息"
, JOptionPane.DEFAULT_OPTION,
JOptionPane.ERROR_MESSAGE,
null, null, null)
}
else
{
try
{
ResultSet rs//声明记录集
String sql="select * from 管理权限 where name='"+jTextField1.getText()+"'"
rs = sqlcx.Rs_jiluji(sql)
if (rs.next())
{
if(jPasswordField1.getText().equals(rs.getString(2)))
{
success()
wo.setBounds(60,40,700,600)
wo.setVisible(true)
this.dispose()
}
else
{
JOptionPane.showOptionDialog(this,"密码错误", "错误信息"
, JOptionPane.DEFAULT_OPTION,
JOptionPane.ERROR_MESSAGE,
null, null, null)
}
}
else
{
JOptionPane.showOptionDialog(this,"没有所要找的用户名", "错误信息"
, JOptionPane.DEFAULT_OPTION,
JOptionPane.ERROR_MESSAGE,
null, null, null)
}
}
catch(Exception c){
JOptionPane.showOptionDialog(this,"连接数据库失败", "错误信息"
, JOptionPane.DEFAULT_OPTION,
JOptionPane.ERROR_MESSAGE,
null, null, null)
}
}
}
public void jButton2_actionPerformed(ActionEvent e) {
System.exit(0)
}
}
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