java登錄

A. 用java實現一個登錄頁面 可以用什麼方法

那應該用jsp頁面里寫一個表單，主要包括用戶名、密碼等欄位，然後再寫一個提交和重置按鈕，採用post或者get方式把表單數據提交到後台進行處理，比如說通過java的jdbc訪問資料庫，判斷輸入表單的數據是否是已經存在的合法用戶，如果是就跳轉到系統主頁面，如果不是就顯示提示錯誤信息。

B. 用Java編寫注冊登錄程序

什麼都不說了 直接給你代碼吧
package com.moliying.ui;
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.List;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.Arrays;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
public class Login {
private JFrame frame = new JFrame("登錄");
private Container c = frame.getContentPane();
private JTextField username = new JTextField();
private JPasswordField password = new JPasswordField();
private JButton ok = new JButton("確定");
private JButton cancel = new JButton("取消");
public Login() {
frame.setSize(300, 200);
frame.setBounds(450, 300, 300, 200);
c.setLayout(new BorderLayout());
initFrame();
frame.setVisible(true);
}
private void initFrame() {
// 頂部
JPanel titlePanel = new JPanel();
titlePanel.setLayout(new FlowLayout());
titlePanel.add(new JLabel("系統管理員登錄"));
c.add(titlePanel, "North");
// 中部表單
JPanel fieldPanel = new JPanel();
fieldPanel.setLayout(null);
JLabel a1 = new JLabel("用戶名:");
a1.setBounds(50, 20, 50, 20);
JLabel a2 = new JLabel("密 碼:");
a2.setBounds(50, 60, 50, 20);
fieldPanel.add(a1);
fieldPanel.add(a2);
username.setBounds(110, 20, 120, 20);
password.setBounds(110, 60, 120, 20);
fieldPanel.add(username);
fieldPanel.add(password);
c.add(fieldPanel, "Center");
// 底部按鈕
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new FlowLayout());
buttonPanel.add(ok);
buttonPanel.add(cancel);
c.add(buttonPanel, "South");

ok.addActionListener(new ActionListener() {

@Override
public void actionPerformed(ActionEvent e) {
System.out.println(username.getText().toString());
}
});

cancel.addActionListener(new ActionListener() {

@Override
public void actionPerformed(ActionEvent e) {
frame.setVisible(false);
}
});
}
public static void main(String[] args) {
// new Login();

String ss = "abbabbbaabbbccba";

System.out.println(ss.split("b").length);

}
}

C. 用java編程實現用戶注冊並進行登錄操作

String username = "",password = "",passwordagain = ""; // 定義用戶名和密碼

將該變數等於為全局變數 或局部變數即可

D. java注冊登錄

不清楚LZ的意思，不連接資料庫么？

E. Java中登陸時如何實現的

如果時java web開發的話，那就是跟資料庫掛鉤了。用戶輸入用戶名和密碼，然後後台程序和資料庫保存的用戶名和密碼進行比較，如果成功，就進入允許的界面，如果不成功，重新回到登錄界面，或者返回網站首頁。
希望能幫到你！！！

F. java怎樣實現登錄驗證

• 1.打開編程工具：

  打開java編程的界面，採用的是eclipse軟體；

  

G. 用JAVA編寫一個登陸系統。

第一個java文件LogoingDemo.java

importjava.util.Scanner;

publicclassLogoingDemo{
	publicstaticvoidmain(String[]args){
		System.out.println("請輸入用戶名");
		Scannersc=newScanner(System.in);
		Stringname=sc.nextLine();
		System.out.println("請輸入密碼");
		Stringpsw=sc.nextLine();
		sc.close();
		CheckDemocd=newCheckDemo(name,psw);//用戶名和密碼傳入驗證類
		booleanbo=cd.check();//調用方法進行驗證
		if(bo){
			System.out.println("登錄成功");
		}else{
			System.out.println("登錄失敗:提示用戶名admin密碼123");
		}
	}
}

第二個java文件CheckDemo.java

publicclassCheckDemo{
	publicStringname;
	publicStringpsw;
	publicCheckDemo(Stringname,Stringpsw){//構造器
		this.name=name;
		this.psw=psw;
	}
	publicbooleancheck(){
		//用戶名密碼不能為空.用戶名=admin密碼=123
		if(name!=null&&psw!=null&&name.equals("admin")&&psw.equals("123")){
			returntrue;
		}
		returnfalse;
	}
}

效果

請輸入用戶名
admin
請輸入密碼
123
登錄成功
------------------------------------
請輸入用戶名
add
請輸入密碼
123
登錄失敗:提示用戶名admin密碼123

H. java實現簡單登錄界面

自己寫的比較規范的代碼，都有注釋:

import javax.swing.JFrame;//框架
import javax.swing.JPanel;//面板
import javax.swing.JButton;//按鈕
import javax.swing.JLabel;//標簽
import javax.swing.JTextField;//文本框
import java.awt.Font;//字體
import java.awt.Color;//顏色
import javax.swing.JPasswordField;//密碼框
import java.awt.event.ActionListener;//事件監聽
import java.awt.event.ActionEvent;//事件處理
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);//設置關閉框架的同時結束程序
this.setSize(300,200);//設置框架大小為長300,寬200
this.setResizable(false);//設置框架不可以改變大小
this.setTitle("用戶登錄");//設置框架標題
this.pnluser.setLayout(null);//設置面板布局管理
this.pnluser.setBackground(Color.cyan);//設置面板背景顏色
this.lbluserLogIn.setText("用戶登錄");//設置標簽標題
this.lbluserLogIn.setFont(new Font("宋體",Font.BOLD | Font.ITALIC,14));//設置標簽字體
this.lbluserLogIn.setForeground(Color.RED);//設置標簽字體顏色
this.lbluserName.setText("用戶名:");
this.lbluserPWD.setText("密 碼:");
this.btnSub.setText("登錄");
this.btnReset.setText("重置");
this.lbluserLogIn.setBounds(120,15,60,20);//設置標簽x坐標120,y坐標15,長60,寬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()//匿名類實現ActionListener介面
{
public void actionPerformed(ActionEvent e){
btnsub_ActionEvent(e);
}
}
);
this.btnReset.setBounds(155,120,60,20);
this.btnReset.addActionListener(new ActionListener()//匿名類實現ActionListener介面
{
public void actionPerformed(ActionEvent e){
btnreset_ActionEvent(e);
}
}
);
this.pnluser.add(lbluserLogIn);//載入標簽到面板
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);//載入面板到框架
this.setVisible(true);//設置框架可顯
}

public void btnsub_ActionEvent(ActionEvent e){
String name = txtName.getText();
String pwd = String.valueOf(pwdPwd.getPassword());
if(name.equals("")){
JOptionPane.showMessageDialog(null,"賬號不能為空","錯誤",JOptionPane.ERROR_MESSAGE);
return;
}else if (pwd.equals("")){
JOptionPane.showMessageDialog(null,"密碼不能為空","錯誤",JOptionPane.ERROR_MESSAGE);
return;
}else if(true){
this.dispose();
}else{
JOptionPane.showMessageDialog(null,"賬號或密碼錯誤","錯誤",JOptionPane.ERROR_MESSAGE);
return;
}
}

public void btnreset_ActionEvent(ActionEvent e){
txtName.setText("");
pwdPwd.setText("");
}

public static void main(String[] args){
new UserLogIn();
}
}

I. 如何用java做登錄界面

import javax.swing.JFrame;//框架
import javax.swing.JPanel;//面板
import javax.swing.JButton;//按鈕
import javax.swing.JLabel;//標簽
import javax.swing.JTextField;//文本框
import java.awt.Font;//字體
import java.awt.Color;//顏色
import javax.swing.JPasswordField;//密碼框
import java.awt.event.ActionListener;//事件監聽
import java.awt.event.ActionEvent;//事件處理
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);//設置關閉框架的同時結束程序
this.setSize(300,200);//設置框架大小為長300,寬200
this.setResizable(false);//設置框架不可以改變大小
this.setTitle("用戶登錄");//設置框架標題
this.pnluser.setLayout(null);//設置面板布局管理
this.pnluser.setBackground(Color.cyan);//設置面板背景顏色
this.lbluserLogIn.setText("用戶登錄");//設置標簽標題
this.lbluserLogIn.setFont(new Font("宋體",Font.BOLD | Font.ITALIC,14));//設置標簽字體
this.lbluserLogIn.setForeground(Color.RED);//設置標簽字體顏色
this.lbluserName.setText("用戶名:");
this.lbluserPWD.setText("密 碼:");
this.btnSub.setText("登錄");
this.btnReset.setText("重置");
this.lbluserLogIn.setBounds(120,15,60,20);//設置標簽x坐標120,y坐標15,長60,寬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()//匿名類實現ActionListener介面
{
public void actionPerformed(ActionEvent e){
btnsub_ActionEvent(e);
}
}
);
this.btnReset.setBounds(155,120,60,20);
this.btnReset.addActionListener(new ActionListener()//匿名類實現ActionListener介面
{
public void actionPerformed(ActionEvent e){
btnreset_ActionEvent(e);
}
}
);
this.pnluser.add(lbluserLogIn);//載入標簽到面板
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);//載入面板到框架
this.setVisible(true);//設置框架可顯
}

public void btnsub_ActionEvent(ActionEvent e){
String name = txtName.getText();
String pwd = String.valueOf(pwdPwd.getPassword());
if(name.equals("")){
JOptionPane.showMessageDialog(null,"賬號不能為空","錯誤",JOptionPane.ERROR_MESSAGE);
return;
}else if (pwd.equals("")){
JOptionPane.showMessageDialog(null,"密碼不能為空","錯誤",JOptionPane.ERROR_MESSAGE);
return;
}else if(true){
this.dispose();
}else{
JOptionPane.showMessageDialog(null,"賬號或密碼錯誤","錯誤",JOptionPane.ERROR_MESSAGE);
return;
}
}

public void btnreset_ActionEvent(ActionEvent e){
txtName.setText("");
pwdPwd.setText("");
}

public static void main(String[] args){
new UserLogIn();
}
}

J. java編寫用戶登錄

代碼發給你，如果什麼都不懂的話，估計你也難以運行成功，而且圖片也沒有，要自己會改就能運行了。這些代碼希望能幫到你！

資料庫文件：

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('李連傑','123')
insert into userInfo(userName,password) values('成龍','123')
insert into userInfo(userName,password) values('甄子丹','123')
insert into userInfo(userName,password) values('趙文卓','123')
insert into userInfo(userName,password) values('吳京','123')
insert into userInfo(userName,password) values('周星馳','123')
insert into userInfo(userName,password) values('劉德華','123')

載入驅動類：

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;
}

}

連接資料庫類：

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;
}
}

登錄類代碼：

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("系統登陸");
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("登陸");
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("登錄成功");
//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, "密碼不能為空");
}else{
JOptionPane.showMessageDialog(null, "密碼不正確，請重新輸入");
}
}

}
});
}
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);
}

}