「java登录程序」java登录界面代码简单
本篇文章给大家谈谈java登录程序，以及java登录界面代码简单对应的知识点，希望对各位有所帮助，不要忘了收藏本站喔。
本文目录一览：
- 1、怎么用JAVA写一个用户登入程序
- 2、用Java编写注册登录程序
- 3、用java程序编写一个简单的登录界面怎么写？
- 4、java完成系统登录程序
- 5、模拟一个简单的用户登陆程序，判断登录的用户名和密码是否正确，输出登录判断结果，用java怎么写？
怎么用JAVA写一个用户登入程序
同意楼上的说法，具体点可以这样：创建一个用户表，里边包括LoginName（登录名），UserName（用户名），Password（密码），Age（年龄），Address（地址）。然后编写Java程序（用MVC架构）模型层（M）：DBConnection.java（负责连接数据库）
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.*;
public class DBConnection {
private static final String DRIVER_CLASS = "sun.jdbc.odbc.JdbcOdbcDriver";
private static final String DB_URL = "jdbc:odbc:text";
public DBConnection() {
}
public static Connection getConnection() {
Connection conn = null;
try {
Class.forName(DRIVER_CLASS);
conn = DriverManager.getConnection(DB_URL);
} catch (SQLException ex) {
System.out.println(ex.getMessage());
} catch (ClassNotFoundException ex) {
System.out.println(ex.getMessage());
}
return conn;
}
}
第2个负责数据库查询操作的类：DBUserManager.java
import edu.systop.text.model.entity.User;
import edu.systop.text.model.dao.DBConnection;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.DriverManager;
import java.sql.*;
public class DBUserManager {
private static final String SQL_SELECT =
"SELECT LoginName,UserName,PassWord,Age,Address FROM UserInfo WHERE LoginName = ? AND PassWord = ?";
public DBUserManager() {
}
public boolean checkDB(User u) {
boolean b = false;
Connection conn = null;
PreparedStatement psmt = null;
ResultSet rs = null;
conn = DBConnection.getConnection();
try {
psmt = conn.prepareStatement(SQL_SELECT);
psmt.setString(1, u.getLoginName());
psmt.setString(2, u.getPassWord());
rs = psmt.executeQuery();
b = rs.next();
if (rs.next()) {
b = true;
}
} catch (SQLException ex) {
System.out.println(ex.getMessage());
} finally {
cleanDB(rs, psmt, conn);
}
return b;
}
public User checkBC(User u) {
Connection conn = null;
PreparedStatement psmt = null;
ResultSet rs = null;
User tmp = new User();
conn = DBConnection.getConnection();
try {
psmt = conn.prepareStatement(SQL_SELECT);
psmt.setString(1, u.getLoginName());
psmt.setString(2, u.getPassWord());
rs = psmt.executeQuery();
if (rs.next()) {
tmp.setLoginName(rs.getString(1));
tmp.setUserName(rs.getString(2));
tmp.setAge(rs.getInt(4));
tmp.setAddress(rs.getString(5));
}
} catch (SQLException ex) {
System.out.println(ex.getMessage());
} finally {
cleanDB(rs, psmt, conn);
}
return tmp;
}
public void cleanDB(ResultSet rs, PreparedStatement psmt, Connection conn) {
try {
if (rs != null) {
rs.close();
}
if (psmt != null) {
psmt.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException ex) {
System.out.println(ex.getMessage());
}
}
第3个实体用户类：User.java
package edu.systop.text.model.entity;
public class User {
private String loginName;
private String userName;
private String passWord;
private int age;
private String address;
public User() {
}
public void setLoginName(String loginName) {
this.loginName = loginName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public void setPassWord(String passWord) {
this.passWord = passWord;
}
public void setAge(int age) {
this.age = age;
}
public void setAddress(String address) {
this.address = address;
}
public String getLoginName() {
return loginName;
}
public String getUserName() {
return userName;
}
public String getPassWord() {
return passWord;
}
public int getAge() {
return age;
}
public String getAddress() {
return address;
}
}
然后编写控制层（C）：GetInfoServlet.java
package edu.systop.text.control;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import edu.systop.text.model.entity.User;
import edu.systop.text.model.service.UserManager;
public class GetInfoServlet extends HttpServlet {
private static final String CONTENT_TYPE = "text/html; charset=GBK";
//Initialize global variables
public void init() throws ServletException {
}
//Process the HTTP Get request
public void doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
}
//Process the HTTP Post request
public void doPost(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
String loginName = request.getParameter("loginName");
String passWord = request.getParameter("passWord");
User u = new User();
u.setLoginName(loginName);
u.setPassWord(passWord);
UserManager m = new UserManager();
RequestDispatcher d;
if (m.checkUser(u)) {
User o = m.checkBC(u);
request.setAttribute("JavaBEAN",o);
d = request.getRequestDispatcher("GetInfoUser.jsp");
} else {
d = request.getRequestDispatcher("GetInfoFinale.jsp");
}
d.forward(request, response);
}
//Clean up resources
public void destroy() {
}
}
最后，创建表示层（V）：包括3个Jsp（登录页面GetInfo.jsp、登录成功页面GetInfoUser.jsp、登录失败页面GetInfoFinale.jsp）
上面的就是Jsp结合Servlet用MVC架构写的用户登录程序。
用Java编写注册登录程序
什么都不说了 直接给你代码吧
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("登录");
private Container c = frame.getContentPane();
private JTextField username = new JTextField();
private JPasswordField password = new JPasswordField();
private JButton ok = new JButton("确定");
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() {
// 顶部
JPanel titlePanel = new JPanel();
titlePanel.setLayout(new FlowLayout());
titlePanel.add(new JLabel("系统管理员登录"));
c.add(titlePanel, "North");
// 中部表单
JPanel fieldPanel = new JPanel();
fieldPanel.setLayout(null);
JLabel a1 = new JLabel("用户名:");
a1.setBounds(50, 20, 50, 20);
JLabel a2 = new JLabel("密 码:");
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");
// 底部按钮
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);
}
}
用java程序编写一个简单的登录界面怎么写？
程序如下:
mport java.awt.HeadlessException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
@SuppressWarnings("serial")
public class MainFrame extends JFrame {
JLabel lbl1 = new JLabel("用户名:");
JLabel lbl2 = new JLabel("密 码:");
JTextField txt = new JTextField("admin",20);
JPasswordField pwd = new JPasswordField(20);
JButton btn = new JButton("登录");
JPanel pnl = new JPanel();
private int error = 0;
public MainFrame(String title) throws HeadlessException {
super(title);
init();
}
private void init() {
this.setResizable(false);
pwd.setEchoChar('*');
pnl.add(lbl1);
pnl.add(txt);
btn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if ("admin".equal花憨羔窖薏忌割媳公颅s(new String(pwd.getPassword()))){
pnl.removeAll();
JLabel lbl3 = new JLabel();
ImageIcon icon = new ImageIcon(this.getClass().getResource("pic.jpg"));
lbl3.setIcon(icon);
pnl.add(lbl3);
}
else{
if(error 3){
JOptionPane.showMessageDialog(null,"密码输入错误，请再试一次");
error++;
}
else{
JOptionPane.showMessageDialog(null,"对不起，您不是合法用户");
txt.setEnabled(false);
pwd.setEnabled(false);
btn.setEnabled(false);
}
}
}
});
}
public static void main(String[] args) {
MainFrame frm = new MainFrame("测试");
frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frm.setBounds(100, 100, 300, 120);
frm.setVisible(true);
}
}
编程的注意事项:
1、Java是一门面向对象编程语言，不仅吸收了C++语言的各种优点，还摒弃了C++里难以理解的多继承、指针等概念，因此Java语言具有功能强大和简单易用两个特征。Java语言作为静态面向对象编程语言的代表，极好地实现了面向对象理论，允许程序员以优雅的思维方式进行复杂的编程。
2、 Java具有简单性、面向对象、分布式、健壮性、安全性、平台独立与可移植性、多线程、动态性等特点。Java可以编写桌面应用程序、Web应用程序、分布式系统和嵌入式系统应用程序等。
3、2006年11月13日，Java技术的发明者Sun公司宣布，将Java技术作为免费软件对外发布。Sun公司正式发布的有关Java平台标准版的第一批源代码，以及Java迷你版的可执行源代码。从2007年3月起，全世界所有的开发人员均可对Java源代码进行修改。
java完成系统登录程序
package com.hg;
import java.util.Scanner;
public class Test {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int failCount = 0;
String userName = "";
String pwd = "";
while(true){
while(true){
System.out.print("请输入用户名：");
scanner = new Scanner(System.in);
userName = scanner.nextLine();
if(!"".equals(userName)){
break;
}
}
while(true){
System.out.print("请输入密码：");
scanner = new Scanner(System.in);
pwd = scanner.nextLine();
if(!"".equals(pwd)){
break;
}
}
if("mldn".endsWith(userName) "hello".endsWith(pwd)){
System.out.println("登录成功！");
break;
}else{
System.out.println("用户名或密码错误！");
failCount++;
}
if(failCount = 3){
System.out.println("您已经连续3次输入错误。系统退出。");
break;
}
}
}
}
模拟一个简单的用户登陆程序，判断登录的用户名和密码是否正确，输出登录判断结果，用java怎么写？
package test;\x0d\x0aimport java.util.Scanner;\x0d\x0apublic class TestLogin {\x0d\x0aprivate static final String USERNAME = "Tom";//此处定义用户名\x0d\x0aprivate static final String PASSWORD = "123";//定义密码\x0d\x0apublic static void main(String[] args) {\x0d\x0aScanner sc = new Scanner(System.in);\x0d\x0aSystem.out.print("请输入您的用户名:");\x0d\x0aString username_in = sc.next();\x0d\x0aSystem.out.print("请输入您的密码:");\x0d\x0aString password_in = sc.next();\x0d\x0aif(username_in.equals(USERNAME) password_in.equals(PASSWORD)){\x0d\x0aSystem.out.println("登录成功");\x0d\x0a}else{\x0d\x0aSystem.out.println("用户名或密码错误");\x0d\x0a}\x0d\x0a}\x0d\x0a} \x0d\x0a这是从控制台输入的最简单的方法。
java登录程序的介绍就聊到这里吧，感谢你花时间阅读本站内容，更多关于java登录界面代码简单、java登录程序的信息别忘了在本站进行查找喔。