java登入的代码 登录java代码

java ATM登陆循环代码？

下面是一个简单的登录示例：

代码复制展示：

public class ATMLogin {

public static void main(String[] args) {

// 设置用户名和密码

String username = "gqk";

String password = "520";

// 最多可以登录 3 次

for (int i = 0; i 3; i++) {

// 读取用户输入的用户名和密码

Scanner in = new Scanner(System.in);

System.out.print("请输入用户名：");

String inputUsername = in.nextLine();

System.out.print("请输入密码：");

String inputPassword = in.nextLine();

// 检查用户名和密码是否正确

if (inputUsername.equals(username) inputPassword.equals(password)) {

System.out.println("欢迎" + username + "登录！");

break; // 登录成功，退出循环

} else {

System.out.println("用户名或密码错误，请重新输入！");

}

}

// 如果 3 次登录都失败，则提示用户

System.out.println("卡片已经被锁，请联系客服人员！");

}

}

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相关问答

Q1: Java如何登录token的代码是什么？

首先是Token主类。类很简单

package com.company.util;

import java.util.ArrayList;

import javax.servlet.http.HttpSession;

public class Token {

private static final String TOKEN_LIST_NAME = "tokenList";

public static final String TOKEN_STRING_NAME = "token";

private static ArrayList getTokenList(HttpSession session) {

Object obj = session.getAttribute(TOKEN_LIST_NAME);

if (obj != null) {

return (ArrayList) obj;

} else {

ArrayList tokenList = new ArrayList();

session.setAttribute(TOKEN_LIST_NAME, tokenList);

return tokenList;

}

}

private static void saveTokenString(String tokenStr, HttpSession session) {

ArrayList tokenList = getTokenList(session);

tokenList.add(tokenStr);

session.setAttribute(TOKEN_LIST_NAME, tokenList);

}

private static String generateTokenString(){

return new Long(System.currentTimeMillis()).toString();

}

/** *//**

* Generate a token string, and save the string in session, then return the token string.

*

* @param HttpSession

* session

* @return a token string used for enforcing a single request for a particular transaction.

*/

public static String getTokenString(HttpSession session) {

String tokenStr = generateTokenString();

saveTokenString(tokenStr, session);

return tokenStr;

}

/** *//**

* check whether token string is valid. if session contains the token string, return true.

* otherwise, return false.

*

* @param String

* tokenStr

* @param HttpSession

* session

* @return true: session contains tokenStr; false: session is null or tokenStr is id not in session

*/

public static boolean isTokenStringValid(String tokenStr, HttpSession session) {

boolean valid = false;

if(session != null){

ArrayList tokenList = getTokenList(session);

if (tokenList.contains(tokenStr)) {

valid = true;

tokenList.remove(tokenStr);

}

}

return valid;

}

}

在jsp页面端。

首先import该类：

%@ page import="com.company.util.Token" %

表单包含隐藏的token字符串:

form

input type="hidden" name="%=Token.TOKEN_STRING_NAME %" value="%=Token.getTokenString(session) %"

/form

在Servlet中添加如下代码。

if(Token.isTokenStringValid(request.getParameter(Token.TOKEN_STRING_NAME), request.getSession())){

//进行正常业务流程

Q2: 求JAVA实现用户登录界面代码？

你要先学会截图哦,你发的看不清楚,重新写了一个你参考参考!

import java.awt.GridLayout;

import javax.swing.ButtonGroup;

import javax.swing.JButton;

import javax.swing.JComboBox;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

import javax.swing.JRadioButton;

import javax.swing.JTextField;

public class Day30A extends JFrame {

private static final long serialVersionUID = 1L;

private JLabel labelName,labelId,labelPass,labelMoney,labelSelect,labelCar;

private JComboBoxString jcb;

private JPanel jp1,jp2,jp3,jp4,jp5,jp6,jp7;

private ButtonGroup btg;

private JRadioButton jr1,jr2;

Day30A(){

this.setTitle("注册账户");

this.setLayout(new GridLayout(7,1));

this.setSize(300,280);

this.setLocationRelativeTo(null);

this.setDefaultCloseOperation(EXIT_ON_CLOSE);

init();

this.setVisible(true);

}

private void init() {

String str="卡片类型1,卡片类型2,卡片类型3,卡片类型4,卡片类型5";

jcb=new JComboBox(str.split(","));

labelId=new JLabel("账号: ");

labelName=new JLabel("姓名: ");

labelPass=new JLabel("密码: ");

labelMoney=new JLabel("开户金额:");

labelSelect=new JLabel("存款类型:");

labelCar=new JLabel("卡片类型:");

addFun1();

addFun2();

}

private void addFun2() {

this.add(jp1);

this.add(jp2);

this.add(jp3);

this.add(jp4);

this.add(jp5);

this.add(jp6);

this.add(jp7);

}

private void addFun1() {

jp1=new JPanel();

jp1.add(labelId);

jp1.add(new JTextField(15));

jp2=new JPanel();

jp2.add(labelName);

jp2.add(new JTextField(15));

jp3=new JPanel();

jp3.add(labelPass);

jp3.add(new JTextField(15));

jp4=new JPanel();

jp4.add(labelMoney);

jp4.add(new JTextField(13));

jp5=new JPanel();

jp5.add(labelSelect);

btg=new ButtonGroup();

jr1=new JRadioButton("定期");

jr2=new JRadioButton("活期",true);

btg.add(jr1);

btg.add(jr2);

jp5.add(jr1);

jp5.add(jr2);

jp6=new JPanel();

jp6.add(labelCar);

jp6.add(jcb);

jp7=new JPanel();

jp7.add(new JButton("确定"));

jp7.add(new JButton("取消"));

}

public static void main(String[] args) {

new Day30A();

}

}

Q3: 登陆界面的java代码怎么写？

import java.awt.*;

import javax.swing.*;

import java.awt.event.*;

import java.sql.*;

class LoginFrm extends JFrame implements ActionListener

{

JLabel lbl1=new JLabel("用户名");

JLabel lbl2=new JLabel("密码");

JTextField txt=new JTextField(15);

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(3,2,10,10));

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("sun.jdbc.odbc.JdbcOdbcDriver")；

Connection con=DriverManager.getConnection("jdbc:odbc:MyDB","","");

Statement cmd=con.createStatement();

ResultSet rs=cmd.executeQuery("select * from loginAndpassword where login='"+txt.getText()+"' and password='"+pf.getText()+"'");

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)

{

txt.setText("");

pf.setText("");

}

}

}

public static void main(String arg[])

{

JFrame.setDefaultLookAndFeelDecorated(true);

LoginFrm frm=new LoginFrm();

frm.setSize(400,200);

frm.setVisible(true);

}

}

Q4: 用java写一个登录界面的代码，哪位大神会啊，谢谢。

import java.awt.Dimension;

import java.awt.Toolkit;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JPasswordField;

import javax.swing.JTextField;

public class Test26 {

public static void main(String[] args) {

final String userName = "abc";

final String passwrod = "123";

JFrame jFrame = new JFrame("登陆界面");

Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();

jFrame.setBounds(((int)dimension.getWidth() - 200) / 2, ((int)dimension.getHeight() - 300) / 2, 200, 150);

jFrame.setResizable(false);

jFrame.setLayout(null);

jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JLabel label1 = new JLabel("姓名");

label1.setBounds(10, 10, 100, 30);

jFrame.add(label1);

JLabel label2 = new JLabel("密码");

label2.setBounds(10, 40, 100, 30);

jFrame.add(label2);

final JTextField text1 = new JTextField();

text1.setBounds(50, 15, 130, 20);

jFrame.add(text1);

final JPasswordField text2 = new JPasswordField();

text2.setBounds(50, 45, 130, 20);

jFrame.add(text2);

JButton button = new JButton("Login");

button.setBounds(10, 75, 170, 40);

button.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

if(userName.equals(text1.getText())  passwrod.equals(text2.getText())) {

JOptionPane.showMessageDialog(null, "登陆成功误", "提示", JOptionPane.INFORMATION_MESSAGE);

} else {

JOptionPane.showMessageDialog(null, "错误", "提示", JOptionPane.ERROR_MESSAGE);

text1.setText("");

text2.setText("");

}

}

});

jFrame.add(button);

jFrame.setVisible(true);

}

}

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