java登陆
1. 用java编写一个登陆系统。
第一个java文件LogoingDemo.java
importjava.util.Scanner;
publicclassLogoingDemo{
publicstaticvoidmain(String[]args){
System.out.println("请输入用户名");
Scannersc=newScanner(System.in);
Stringname=sc.nextLine();
System.out.println("请输入密码");
Stringpsw=sc.nextLine();
sc.close();
CheckDemocd=newCheckDemo(name,psw);//用户名和密码传入验证类
booleanbo=cd.check();//调用方法进行验证
if(bo){
System.out.println("登录成功");
}else{
System.out.println("登录失败:提示用户名admin密码123");
}
}
}
第二个java文件CheckDemo.java
publicclassCheckDemo{
publicStringname;
publicStringpsw;
publicCheckDemo(Stringname,Stringpsw){//构造器
this.name=name;
this.psw=psw;
}
publicbooleancheck(){
//用户名密码不能为空.用户名=admin密码=123
if(name!=null&&psw!=null&&name.equals("admin")&&psw.equals("123")){
returntrue;
}
returnfalse;
}
}效果
请输入用户名
admin
请输入密码
123
登录成功
------------------------------------
请输入用户名
add
请输入密码
123
登录失败:提示用户名admin密码123
2. 如何用java做登录界面
import javax.swing.JFrame;//框架
import javax.swing.JPanel;//面板
import javax.swing.JButton;//按钮
import javax.swing.JLabel;//标签
import javax.swing.JTextField;//文本框
import java.awt.Font;//字体
import java.awt.Color;//颜色
import javax.swing.JPasswordField;//密码框
import java.awt.event.ActionListener;//事件监听
import java.awt.event.ActionEvent;//事件处理
import javax.swing.JOptionPane;//消息窗口public class UserLogIn extends JFrame{
public JPanel pnluser;
public JLabel lbluserLogIn;
public JLabel lbluserName;
public JLabel lbluserPWD;
public JTextField txtName;
public JPasswordField pwdPwd;
public JButton btnSub;
public JButton btnReset;
public UserLogIn(){
pnluser = new JPanel();
lbluserLogIn = new JLabel();
lbluserName = new JLabel();
lbluserPWD = new JLabel();
txtName = new JTextField();
pwdPwd = new JPasswordField();
btnSub = new JButton();
btnReset = new JButton();
userInit();
}
public void userInit(){
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设置关闭框架的同时结束程序
this.setSize(300,200);//设置框架大小为长300,宽200
this.setResizable(false);//设置框架不可以改变大小
this.setTitle("用户登录");//设置框架标题
this.pnluser.setLayout(null);//设置面板布局管理
this.pnluser.setBackground(Color.cyan);//设置面板背景颜色
this.lbluserLogIn.setText("用户登录");//设置标签标题
this.lbluserLogIn.setFont(new Font("宋体",Font.BOLD | Font.ITALIC,14));//设置标签字体
this.lbluserLogIn.setForeground(Color.RED);//设置标签字体颜色
this.lbluserName.setText("用户名:");
this.lbluserPWD.setText("密 码:");
this.btnSub.setText("登录");
this.btnReset.setText("重置");
this.lbluserLogIn.setBounds(120,15,60,20);//设置标签x坐标120,y坐标15,长60,宽20
this.lbluserName.setBounds(50,55,60,20);
this.lbluserPWD.setBounds(50,85,60,25);
this.txtName.setBounds(110,55,120,20);
this.pwdPwd.setBounds(110,85,120,20);
this.btnSub.setBounds(85,120,60,20);
this.btnSub.addActionListener(new ActionListener()//匿名类实现ActionListener接口
{
public void actionPerformed(ActionEvent e){
btnsub_ActionEvent(e);
}
}
);
this.btnReset.setBounds(155,120,60,20);
this.btnReset.addActionListener(new ActionListener()//匿名类实现ActionListener接口
{
public void actionPerformed(ActionEvent e){
btnreset_ActionEvent(e);
}
}
);
this.pnluser.add(lbluserLogIn);//加载标签到面板
this.pnluser.add(lbluserName);
this.pnluser.add(lbluserPWD);
this.pnluser.add(txtName);
this.pnluser.add(pwdPwd);
this.pnluser.add(btnSub);
this.pnluser.add(btnReset);
this.add(pnluser);//加载面板到框架
this.setVisible(true);//设置框架可显
}
public void btnsub_ActionEvent(ActionEvent e){
String name = txtName.getText();
String pwd = String.valueOf(pwdPwd.getPassword());
if(name.equals("")){
JOptionPane.showMessageDialog(null,"账号不能为空","错误",JOptionPane.ERROR_MESSAGE);
return;
}else if (pwd.equals("")){
JOptionPane.showMessageDialog(null,"密码不能为空","错误",JOptionPane.ERROR_MESSAGE);
return;
}else if(true){
this.dispose();
}else{
JOptionPane.showMessageDialog(null,"账号或密码错误","错误",JOptionPane.ERROR_MESSAGE);
return;
}
}
public void btnreset_ActionEvent(ActionEvent e){
txtName.setText("");
pwdPwd.setText("");
}
public static void main(String[] args){
new UserLogIn();
}
}
3. java怎样实现登录验证
1.打开编程工具：
打开java编程的界面，采用的是eclipse软件；
4. java编写用户登录
代码发给你，如果什么都不懂的话，估计你也难以运行成功，而且图片也没有，要自己会改就能运行了。这些代码希望能帮到你！
数据库文件：
create database hotel_Flyer
go
use hotel_Flyer
create table userInfo(
id int primary key identity(1,1),
userName varchar(20),
password varchar(10),
realName nvarchar(20),
sex nvarchar(2),
age int,
favorite nvarchar(100),
telNum varchar(12),
email varchar(50),
address nvarchar(200)
)
go
insert into userInfo(userName,password) values('李连杰','123')
insert into userInfo(userName,password) values('成龙','123')
insert into userInfo(userName,password) values('甄子丹','123')
insert into userInfo(userName,password) values('赵文卓','123')
insert into userInfo(userName,password) values('吴京','123')
insert into userInfo(userName,password) values('周星驰','123')
insert into userInfo(userName,password) values('刘德华','123')
加载驱动类：
public class ConTosql {
Connection con=null;
public Connection getConnection() throws Exception{
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
con= DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;databaseName=hotel_Flyer", "sa", "sa");
return con;
}
}
连接数据库类：
public class DengluUC {
Connection con=null;
PreparedStatement stm=null;
ResultSet rs=null;
public boolean checkUser(String user,String pwd){
boolean tof=false;
try {
ConToSQL cts=new ConToSQL();
con=cts.getConnection();
stm=con.prepareStatement("select password from userInfo where userName=?");
stm.setString(1, user);
rs=stm.executeQuery();
if(rs.next()){
if(rs.getString(1).equals(pwd)){
tof= true;
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} /*finally{
try {
rs.close();
stm.close();
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
return tof;
}*/
return tof;
}
}
登录类代码：
package com.hbsoft.hotel_Flyer.login;
import com.hbsoft.hotel_Flyer.usermanagerForm.*;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import java.awt.Rectangle;
import javax.swing.BorderFactory;
import java.awt.Color;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.swing.JComboBox;
import javax.swing.JOptionPane;
import javax.swing.JPasswordField;
import javax.swing.JButton;
import javax.swing.ImageIcon;
import javax.swing.JTextField;
import javax.swing.text.html.Option;
import com.hbsoft.hotel_Flyer.proc.Process;
import java.awt.Point;
import java.sql.*;
import com.hbsoft.hotel_Flyer.database.*;
public class Denglu {
private JFrame jFrame = null; // @jve:decl-index=0:visual-constraint="61,26"
private JPanel jContentPane = null;
private JPanel jPanel = null;
private JComboBox jComboBox = null;
private JLabel jL4 = null;
private JLabel jLabel1 = null;
private JPasswordField jPasswordField = null;
private JButton jB1 = null;
private JButton jB2 = null;
private JComboBox jComboBox1 = null;
private JLabel jLabel = null;
private JLabel jLabel2 = null;
private Connection con=null; // @jve:decl-index=0:
private Statement sts=null;
private ResultSet rs=null;
private DatabaseMetaData dmd=null;
private int rowCount=0;
/**
* This method initializes jFrame
*
* @return javax.swing.JFrame
*/
public JFrame getJFrame() {
if (jFrame == null) {
jFrame = new JFrame("系统登陆");
jFrame.setSize(new Dimension(854, 539));
jFrame.setLocation(new Point(100, 100));
jFrame.setContentPane(getJContentPane());
jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jFrame.setResizable(false);
}
return jFrame;
}
/**
* This method initializes jContentPane
*
* @return javax.swing.JPanel
*/
private JPanel getJContentPane() {
if (jContentPane == null) {
jLabel2 = new JLabel();
jLabel2.setBounds(new Rectangle(3, 4, 845, 503));
jLabel2.setIcon(new ImageIcon("E:/java\uff088\uff09\u73ed\u5468\u67ab/\u7b2c\u5341\u7ec4\u5de5\u4f5c\u7ad9/hotel_Flyer/\u767b\u5f55\u80cc\u666f.jpg"));
jLabel2.setText("");
jLabel = new JLabel();
jLabel.setText("");
jLabel.setIcon(new ImageIcon(getClass().getResource("/com/hbsoft/hotel_Flyer/img/\u767b\u5f55\u80cc\u666f.jpg")));
jLabel.setBounds(new Rectangle(-1, 1, 851, 509));
jLabel1 = new JLabel();
jLabel1.setBounds(new Rectangle(438, 141, 363, 231));
jLabel1.setText("");
jL4 = new JLabel();
jL4.setBounds(new Rectangle(484, 341, 289, 28));
jL4.setHorizontalAlignment(SwingConstants.CENTER);
Timer t =new Timer(1000,new ActionListener(){
public void actionPerformed(ActionEvent e) {
Date d=new Date();
SimpleDateFormat df = new SimpleDateFormat("yy-MM-dd hh:mm:ss");
jL4.setText(df.format(d));
}
});
t.start();
jContentPane = new JPanel();
jContentPane.setLayout(null);
jContentPane.setBorder(BorderFactory.createLineBorder(Color.cyan, 2));
jContentPane.setFont(new Font("\u96b6\u4e66", Font.PLAIN, 14));
jContentPane.add(getJPanel(), null);
jContentPane.add(jL4, null);
jContentPane.add(jLabel1, null);
jContentPane.add(getJPasswordField(), null);
jContentPane.add(getJB1(), null);
jContentPane.add(getJB2(), null);
jContentPane.add(getJComboBox1(), null);
jContentPane.add(jLabel, null);
jContentPane.add(jLabel2, null);
jContentPane.add(jLabel, null);
}
return jContentPane;
}
/**
* This method initializes jPanel
*
* @return javax.swing.JPanel
*/
private JPanel getJPanel() {
if (jPanel == null) {
jPanel = new JPanel();
jPanel.setLayout(new GridBagLayout());
jPanel.setBounds(new Rectangle(0, 0, 415, 0));
}
return jPanel;
}
/**
* This method initializes jB1
*
* @return javax.swing.JButton
*/
void ThisDispose(){
this.getJFrame().dispose();
}
/**
* This method initializes jPasswordField
*
* @return javax.swing.JPasswordField
*/
private JPasswordField getJPasswordField() {
if (jPasswordField == null) {
jPasswordField = new JPasswordField();
jPasswordField.setBounds(new Rectangle(570, 263, 201, 29));
}
return jPasswordField;
}
/**
* This method initializes jB1
*
* @return javax.swing.JButton
*/
/*void ThisdDispose(){
this.getJFrame().dispose();
}*/
private JButton getJB1() {
if (jB1 == null) {
jB1 = new JButton();
jB1.setBounds(new Rectangle(489, 313, 103, 35));
jB1.setText("登陆");
jB1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent e) {
if(new DengluUC().checkUser(jComboBox1.getSelectedItem().toString(), new String(jPasswordField.getPassword()))){
//message.setText("登录成功");
//message.setForeground(new Color(255,0,0));
new Process((String)jComboBox1.getSelectedItem()).setVisible(true);
ThisDispose();
}else{
if(new String(jPasswordField.getPassword()).length()==0){
JOptionPane.showMessageDialog(null, "密码不能为空");
}else{
JOptionPane.showMessageDialog(null, "密码不正确，请重新输入");
}
}
}
});
}
return jB1;
}
/**
* This method initializes jB2
*
* @return javax.swing.JButton
*/
private JButton getJB2() {
if (jB2 == null) {
jB2 = new JButton();
jB2.setBounds(new Rectangle(642, 312, 103, 35));
jB2.setText("退出");
jB2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent e) {
System.exit(0);
}
});
}
return jB2;
}
/**
* This method initializes jComboBox1
*
* @return javax.swing.JComboBox
*/
public void getResultSet(){
try{
con=new ConToSQL().getConnection();
sts=con.createStatement();
rs=sts.executeQuery("select * from userInfo");
}catch(Exception e){
e.printStackTrace();
}
}
public int getRowCount(){
try {
rs.last();
if (rs.isLast()) {
rowCount = rs.getRow();
}
} catch (Exception e) {
e.printStackTrace();
}
return rowCount;
}
public void closeData(){
try{
rs.close();
sts.close();
con.close();
}catch(SQLException e){
e.printStackTrace();
}
}
private JComboBox getJComboBox1() {
getResultSet();
String [] arr=new String[7];
int i=0;
try {
while (rs.next()) {
if(i<arr.length){
arr[i] = rs.getString(2);
i++;}
}
} catch (Exception e) {
e.printStackTrace();
}
if (jComboBox1 == null) {
jComboBox1 = new JComboBox(arr);
closeData();
jComboBox1.setBounds(new Rectangle(569, 218, 201, 29));
}
return jComboBox1;
}
public static void main(String [] args) throws Exception{
// javax.swing.UIManager.setLookAndFeel("com.jtattoo.plaf.mcwin.McWinLookAndFeel");
javax.swing.UIManager.setLookAndFeel("com.jtattoo.plaf.acryl.AcrylLookAndFeel");
new Denglu().getJFrame().setVisible(true);
}
}
5. Java中登陆时如何实现的
如果时java web开发的话，那就是跟数据库挂钩了。用户输入用户名和密码，然后后台程序和数据库保存的用户名和密码进行比较，如果成功，就进入允许的界面，如果不成功，重新回到登录界面，或者返回网站首页。
希望能帮到你！！！
6. java语言实现用户注册和登录
//这个是我写的，里面有连接数据库的部分。你可以拿去参考一下
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.(true);
LoginFrm frm = new LoginFrm();
frm.setSize(400, 200);
frm.setVisible(true);
}
}
7. java实现简单登录界面
自己写的比较规范的代码，都有注释:
import javax.swing.JFrame;//框架
import javax.swing.JPanel;//面板
import javax.swing.JButton;//按钮
import javax.swing.JLabel;//标签
import javax.swing.JTextField;//文本框
import java.awt.Font;//字体
import java.awt.Color;//颜色
import javax.swing.JPasswordField;//密码框
import java.awt.event.ActionListener;//事件监听
import java.awt.event.ActionEvent;//事件处理
import javax.swing.JOptionPane;//消息窗口
public class UserLogIn extends JFrame{
public JPanel pnluser;
public JLabel lbluserLogIn;
public JLabel lbluserName;
public JLabel lbluserPWD;
public JTextField txtName;
public JPasswordField pwdPwd;
public JButton btnSub;
public JButton btnReset;
public UserLogIn(){
pnluser = new JPanel();
lbluserLogIn = new JLabel();
lbluserName = new JLabel();
lbluserPWD = new JLabel();
txtName = new JTextField();
pwdPwd = new JPasswordField();
btnSub = new JButton();
btnReset = new JButton();
userInit();
}
public void userInit(){
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设置关闭框架的同时结束程序
this.setSize(300,200);//设置框架大小为长300,宽200
this.setResizable(false);//设置框架不可以改变大小
this.setTitle("用户登录");//设置框架标题
this.pnluser.setLayout(null);//设置面板布局管理
this.pnluser.setBackground(Color.cyan);//设置面板背景颜色
this.lbluserLogIn.setText("用户登录");//设置标签标题
this.lbluserLogIn.setFont(new Font("宋体",Font.BOLD | Font.ITALIC,14));//设置标签字体
this.lbluserLogIn.setForeground(Color.RED);//设置标签字体颜色
this.lbluserName.setText("用户名:");
this.lbluserPWD.setText("密 码:");
this.btnSub.setText("登录");
this.btnReset.setText("重置");
this.lbluserLogIn.setBounds(120,15,60,20);//设置标签x坐标120,y坐标15,长60,宽20
this.lbluserName.setBounds(50,55,60,20);
this.lbluserPWD.setBounds(50,85,60,25);
this.txtName.setBounds(110,55,120,20);
this.pwdPwd.setBounds(110,85,120,20);
this.btnSub.setBounds(85,120,60,20);
this.btnSub.addActionListener(new ActionListener()//匿名类实现ActionListener接口
{
public void actionPerformed(ActionEvent e){
btnsub_ActionEvent(e);
}
}
);
this.btnReset.setBounds(155,120,60,20);
this.btnReset.addActionListener(new ActionListener()//匿名类实现ActionListener接口
{
public void actionPerformed(ActionEvent e){
btnreset_ActionEvent(e);
}
}
);
this.pnluser.add(lbluserLogIn);//加载标签到面板
this.pnluser.add(lbluserName);
this.pnluser.add(lbluserPWD);
this.pnluser.add(txtName);
this.pnluser.add(pwdPwd);
this.pnluser.add(btnSub);
this.pnluser.add(btnReset);
this.add(pnluser);//加载面板到框架
this.setVisible(true);//设置框架可显
}
public void btnsub_ActionEvent(ActionEvent e){
String name = txtName.getText();
String pwd = String.valueOf(pwdPwd.getPassword());
if(name.equals("")){
JOptionPane.showMessageDialog(null,"账号不能为空","错误",JOptionPane.ERROR_MESSAGE);
return;
}else if (pwd.equals("")){
JOptionPane.showMessageDialog(null,"密码不能为空","错误",JOptionPane.ERROR_MESSAGE);
return;
}else if(true){
this.dispose();
}else{
JOptionPane.showMessageDialog(null,"账号或密码错误","错误",JOptionPane.ERROR_MESSAGE);
return;
}
}
public void btnreset_ActionEvent(ActionEvent e){
txtName.setText("");
pwdPwd.setText("");
}
public static void main(String[] args){
new UserLogIn();
}
}
8. 用java写一个登陆界面代码。
概述
具体框架使用jframe，文本框组件：JTextField；密码框组件：JPasswordField；标签组件：JLabel；复选框组件：JCheckBox；单选框组件：JRadioButton；按钮组件JButton。
登录界面：
Swing 是一个为Java设计的GUI工具包。
Swing是JAVA基础类的一部分。
Swing包括了图形用户界面（GUI）器件如：文本框，按钮，分隔窗格和表。
Swing提供许多比AWT更好的屏幕显示元素。它们用纯Java写成，所以同Java本身一样可以跨平台运行，这一点不像AWT。它们是JFC的一部分。它们支持可更换的面板和主题（各种操作系统默认的特有主题），然而不是真的使用原生平台提供的设备，而是仅仅在表面上模仿它们。这意味着你可以在任意平台上使用JAVA支持的任意面板。轻量级组件的缺点则是执行速度较慢，优点就是可以在所有平台上采用统一的行为。
概念解析：
JFrame– java的GUI程序的基本思路是以JFrame为基础，它是屏幕上window的对象，能够最大化、最小化、关闭。
JPanel– Java图形用户界面(GUI)工具包swing中的面板容器类，包含在javax.swing 包中，可以进行嵌套，功能是对窗体中具有相同逻辑功能的组件进行组合，是一种轻量级容器，可以加入到JFrame窗体中。。
JLabel– JLabel 对象可以显示文本、图像或同时显示二者。可以通过设置垂直和水平对齐方式，指定标签显示区中标签内容在何处对齐。默认情况下，标签在其显示区内垂直居中对齐。默认情况下，只显示文本的标签是开始边对齐；而只显示图像的标签则水平居中对齐。
JTextField–一个轻量级组件，它允许编辑单行文本。
JPasswordField– 允许我们输入了一行字像输入框，但隐藏星号(*) 或点创建密码(密码)
JButton– JButton 类的实例。用于创建按钮类似实例中的 "Login"。
9. java注册登录
不清楚LZ的意思，不连接数据库么？