「java用户登录功能」java登录功能的原理
本篇文章给大家谈谈java用户登录功能，以及java登录功能的原理对应的知识点，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、求用java实现简单的登录和注册功能，主要是为了了解怎样对数据库进行增删改查。和各种请求处理，
- 2、如何用JAVA编写一个简单用户登陆界面？
- 3、JAVA问题：实现用户登录身份验证功能拜托了各位 谢谢
- 4、JAVA中基于C/S的登录功能怎样实现
- 5、java语言实现用户注册和登录
求用java实现简单的登录和注册功能，主要是为了了解怎样对数据库进行增删改查。和各种请求处理，
//User 用户的基本信息，也是USERINFO表中的3个列
package
登陆判断;
public class User {
private String name;
private String loginname;
private String
loginpsw;
public String getName() {
return name;
}
public
void setName(String name) {
this.name = name;
}
public String
getLoginname() {
return loginname;
}
public void
setLoginname(String loginname) {
this.loginname =
loginname;
}
public String getLoginpsw() {
return
loginpsw;
}
public void setLoginpsw(String loginpsw)
{
this.loginpsw = loginpsw;
}
}
//用于注册和登陆的小小代码块
package
登陆判断;
import java.util.Scanner;
public class In {
public static User getUser(){
User u = new User();
Scanner sc =
new
Scanner(System.in);
System.out.println("请输入登陆名");
u.setLoginname(sc.nextLine());
System.out.println("请输入密码");
u.setLoginpsw(sc.nextLine());
return
u;
}
public static User registerUser(){
User u = new
User();
Scanner sc = new
Scanner(System.in);
System.out.println("请注册用户名名");
u.setName(sc.nextLine());
System.out.println("请注册登陆名");
u.setLoginname(sc.nextLine());
System.out.println("请注册密码");
u.setLoginpsw(sc.nextLine());
return
u;
}
}
//登陆时的检查，判断登陆名和密码是否正确，正确则返回 用户名
package 登陆判断;
import java.sql.Connection;
import java.sql.DriverManager;
import
java.sql.PreparedStatement;
import java.sql.ResultSet;
import
java.sql.SQLException;
public class Check {
public static void checkUser(User u)
{
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch
(ClassNotFoundException e) {
e.printStackTrace();
}
String
url = "jdbc:oracle:thin:@localhost:1521:orcl";
String user =
"scott";
String password = "tiger";
Connection conn =
null;
ResultSet rs = null;
PreparedStatement pst =
null;
String sql = "Select name from USERINFO where loginname = ? and
loginpsw = ? ";
try {
conn = DriverManager.getConnection(url, user,
password);
pst = conn.prepareStatement(sql);
pst.setString(1,
u.getLoginname());
pst.setString(2,u.getLoginpsw());
rs =
pst.executeQuery();
while(rs.next()){
u.setName(rs.getString(1));
}
}
catch (SQLException e) {
e.printStackTrace();
}finally{
try
{
rs.close();
pst.close();
conn.close();
} catch
(SQLException e)
{
e.printStackTrace();
}
}
if(u.getName() == null ||
u.getName().isEmpty()){
System.out.println("登陆失败");
}else{
System.out.println("欢迎"+u.getName()+"登陆");
}
}
}
//注册界面，要判断 登陆名是否有重复，有重复则注册失败。有点小疑问，已用注释标出来
package 登陆判断;
import java.sql.Connection;
import java.sql.DriverManager;
import
java.sql.PreparedStatement;
import java.sql.ResultSet;
import
java.sql.SQLException;
import java.sql.Statement;
public class Register {
public static void registUser(User u){
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch
(ClassNotFoundException e) {
e.printStackTrace();
}
String
url = "jdbc:oracle:thin:@localhost:1521:orcl";
String user =
"scott";
String password = "tiger";
Connection conn =
null;
String sql = "Insert Into USERINFO
values(?,?,?)";
PreparedStatement pst =
null;
//判断登陆名是否已经存在
Statement s = null;
ResultSet rs =
null;
String sql_ck = "Select LOGINNAME FROM USERINFO";
try
{
conn = DriverManager.getConnection(url, user, password);
pst =
conn.prepareStatement(sql);
pst.setString(1,
u.getName());
pst.setString(2, u.getLoginname());
pst.setString(3,
u.getLoginpsw());
//判断登陆名是否已经存在
s =
conn.createStatement();
rs =
s.executeQuery(sql_ck);
while(rs.next()){//为什么用 rs.getString(2)会提示
无效的索引呢
if( rs.getString("LOGINNAME").equals(u.getLoginname())
){
System.out.println("登陆名已经存在，注册失败");
break;
}else{
pst.executeUpdate();
System.out.println("注册成功");
break;
}
}
}
catch (SQLException e) {
e.printStackTrace();
}finally{
try
{
rs.close();
pst.close();
s.close();
conn.close();
}
catch (SQLException e)
{
e.printStackTrace();
}
}
}
}
//main界面//
//数据库中表的结构式这样
//name(用户名，用于显示),
//loginname(登录名,即登陆时输入的ID)
//loginpsw(登陆时输入的密码)
package
登陆判断;
import java.util.Scanner;
public class Test {
public static void main(String[] args) {
int chos = 0;
Scanner sc = new
Scanner(System.in);
System.out.println("\t\t登陆请按1\t\t注册请按2");
chos =
sc.nextInt();
switch(chos){
case 1:
Check.checkUser(In.getUser());break;
case 2:
Register.registUser(In.registerUser());break;
default:
System.out.println("请输入正确的选择");break;
}
}
}
如何用JAVA编写一个简单用户登陆界面？
什么都不说了 直接给你代码吧\x0d\x0apackage com.moliying.ui;\x0d\x0aimport java.awt.BorderLayout;\x0d\x0aimport java.awt.Container;\x0d\x0aimport java.awt.FlowLayout;\x0d\x0aimport java.awt.List;\x0d\x0aimport java.awt.event.ActionEvent;\x0d\x0aimport java.awt.event.ActionListener;\x0d\x0aimport java.io.BufferedWriter;\x0d\x0aimport java.io.FileOutputStream;\x0d\x0aimport java.io.OutputStreamWriter;\x0d\x0aimport java.util.ArrayList;\x0d\x0aimport java.util.Arrays;\x0d\x0aimport javax.swing.JButton;\x0d\x0aimport javax.swing.JFrame;\x0d\x0aimport javax.swing.JLabel;\x0d\x0aimport javax.swing.JPanel;\x0d\x0aimport javax.swing.JPasswordField;\x0d\x0aimport javax.swing.JTextField;\x0d\x0apublic class Login {\x0d\x0aprivate JFrame frame = new JFrame("登录");\x0d\x0aprivate Container c = frame.getContentPane();\x0d\x0aprivate JTextField username = new JTextField();\x0d\x0aprivate JPasswordField password = new JPasswordField();\x0d\x0aprivate JButton ok = new JButton("确定");\x0d\x0aprivate JButton cancel = new JButton("取消");\x0d\x0apublic Login() {\x0d\x0aframe.setSize(300, 200);\x0d\x0aframe.setBounds(450, 300, 300, 200);\x0d\x0ac.setLayout(new BorderLayout());\x0d\x0ainitFrame();\x0d\x0aframe.setVisible(true);\x0d\x0a}\x0d\x0aprivate void initFrame() {\x0d\x0a// 顶部\x0d\x0aJPanel titlePanel = new JPanel();\x0d\x0atitlePanel.setLayout(new FlowLayout());\x0d\x0atitlePanel.add(new JLabel("系统管理员登录"));\x0d\x0ac.add(titlePanel, "North");\x0d\x0a// 中部表单\x0d\x0aJPanel fieldPanel = new JPanel();\x0d\x0afieldPanel.setLayout(null);\x0d\x0aJLabel a1 = new JLabel("用户名:");\x0d\x0aa1.setBounds(50, 20, 50, 20);\x0d\x0aJLabel a2 = new JLabel("密 码:");\x0d\x0aa2.setBounds(50, 60, 50, 20);\x0d\x0afieldPanel.add(a1);\x0d\x0afieldPanel.add(a2);\x0d\x0ausername.setBounds(110, 20, 120, 20);\x0d\x0apassword.setBounds(110, 60, 120, 20);\x0d\x0afieldPanel.add(username);\x0d\x0afieldPanel.add(password);\x0d\x0ac.add(fieldPanel, "Center");\x0d\x0a// 底部按钮\x0d\x0aJPanel buttonPanel = new JPanel();\x0d\x0abuttonPanel.setLayout(new FlowLayout());\x0d\x0abuttonPanel.add(ok);\x0d\x0abuttonPanel.add(cancel);\x0d\x0ac.add(buttonPanel, "South");\x0d\x0a\x0d\x0aok.addActionListener(new ActionListener() {\x0d\x0a\x0d\x0a@Override\x0d\x0apublic void actionPerformed(ActionEvent e) {\x0d\x0aSystem.out.println(username.getText().toString());\x0d\x0a}\x0d\x0a});\x0d\x0a\x0d\x0acancel.addActionListener(new ActionListener() {\x0d\x0a\x0d\x0a@Override\x0d\x0apublic void actionPerformed(ActionEvent e) {\x0d\x0aframe.setVisible(false);\x0d\x0a}\x0d\x0a});\x0d\x0a}\x0d\x0apublic static void main(String[] args) {\x0d\x0a//new Login();\x0d\x0a\x0d\x0aString ss = "abbabbbaabbbccba";\x0d\x0a\x0d\x0aSystem.out.println(ss.split("b").length);\x0d\x0a\x0d\x0a}\x0d\x0a}
JAVA问题：实现用户登录身份验证功能拜托了各位 谢谢
这是问题1后台的，我实在不愿意从头到尾都帮你写了，希望这段代码能给你启发，有问题可以问，可是你这样把所有问题都抛出来，实在对你的学习不利，希望你明白这个道理 package com.long1; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.Statement; import java.util.ArrayList; import java.util.List; public class MyJdbc { private Connection con = null; private PreparedStatement ps = null; private Statement st = null; private ResultSet rs = null; private String url = "jdbc:mysql://localhost:3306/snake_db1"; private String name = "root"; private String pass = "123456789"; private String driver = "com.mysql.jdbc.Driver"; public MyJdbc() { try { Class.forName(driver); } catch (Exception e) { e.printStackTrace(); } } private void open() { try { con = DriverManager.getConnection(url, name, pass); } catch (Exception e) { e.printStackTrace(); } } public ListLogin query() { ArrayListLogin arr = null; try { open(); st = con.createStatement(); rs = st.executeQuery("select * from login where flag!=0"); Login l = null; arr = new ArrayListLogin(); while (rs.next()) { l = new Login(); l.setId(rs.getInt(1)); l.setName(rs.getString(2)); l.setPass(rs.getString(3)); l.setFlag(rs.getString(4)); arr.add(l); } } catch (Exception e) { e.printStackTrace(); } finally { close(); } return arr; } public boolean check(String name, String pass) { boolean flag = false; try { open(); ps = con.prepareStatement("select id from login where name=? and pass=? and flag!=0"); ps.setString(1, name); ps.setString(2, pass); rs = ps.executeQuery(); if (rs.next()) { flag = true; } } catch (Exception e) { e.printStackTrace(); } finally { close(); } return flag; } private void close() { try { if (rs != null) { rs.close(); rs = null; } if (ps != null) { ps.close(); ps = null; } if (con != null) { con.close(); con = null; } } catch (Exception e) { e.printStackTrace(); } } }
JAVA中基于C/S的登录功能怎样实现
1，客户端发送LoginRequestKeyMessage，告诉服务器准备登陆，并期望得到公钥。
2，服务器收到LoginRequestKeyMessage后，发送公钥key给客户端。
3，客户端保存公钥key后随机生成一个大整数，并将hash后的值clientNonce发给服务端。
4，服务端收到clientNonce，并随机生成一个大整数，然后照样将它hash后的值serverNonce发给客户端。
5，客户端收到serverNonce，此时此刻，客户端和服务端都有了一致的【clientNonce，serverNonce】且这对值每次登陆都不一样，因为都是由随机大整数hash而来。
6，服务器收到cryptedPassword.....然后就是查询数据库验证。
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.setDefaultLookAndFeelDecorated(true);
LoginFrm frm = new LoginFrm();
frm.setSize(400, 200);
frm.setVisible(true);
}
}
关于java用户登录功能和java登录功能的原理的介绍到此就结束了，不知道你从中找到你需要的信息了吗 ？如果你还想了解更多这方面的信息，记得收藏关注本站。