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用户登录注册流程图
老版：
新版：
登陆界面
注册界面
登陆成功界面
LoginServlet
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.wzc.login.dao.UserDao;
import com.wzc.login.domain.User;
/**
* @description 登录请求处理类
* @author WANGZIC
*/
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//接收表单信息
String username = request.getParameter("username");
String password = request.getParameter("password");
String verifyc = request.getParameter("verifycode");
//设置回显
request.setAttribute("username", username);
request.setAttribute("password", password);
request.setAttribute("verifycode", verifyc);
//获取验证码
String svc =(String) request.getSession().getAttribute("sessionverify");
//根据用户名查询用户
User user =new UserDao().findUser(username);
if(!svc.equalsIgnoreCase(verifyc)){
request.setAttribute("loginError", "* 验证码错误");
request.getRequestDispatcher("/login.jsp").forward(request, response);
return;
}
if(user!=null){
if(user.getPassword().equals(password)){
request.getSession().setAttribute("user", user);
response.sendRedirect("index.jsp");
}else {
request.setAttribute("loginError", "* 密码错误");
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
}else {
request.setAttribute("loginError", "* 用户不存在");
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
}RegistServlet
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.wzc.login.dao.UserDao;
/**
* @description 注册请求处理类
* @author WANGZIC
*/
@WebServlet("/RegistServlet")
public class RegistServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
String username = request.getParameter("username");
String password = request.getParameter("password");
String rpsw = request.getParameter("rpsw");
if(username==null||username.trim().isEmpty()){
request.setAttribute("registError", "用户名不能为空");
request.getRequestDispatcher("/regist.jsp").forward(request, response);
return;
}
if(password==null||password.trim().isEmpty()){
request.setAttribute("registError", "密码不能为空");
request.getRequestDispatcher("/regist.jsp").forward(request, response);
return;
}
if(!password.equals(rpsw)){
request.setAttribute("registError", "密码不一致");
request.getRequestDispatcher("/regist.jsp").forward(request, response);
return;
}
UserDao u = new UserDao();
boolean res = u.addUser(username,password);
if(res){
response.sendRedirect("index.jsp");
}else {
request.setAttribute("registError", "注册失败，该用户名已存在");
request.getRequestDispatcher("/regist.jsp").forward(request, response);
}
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
}
LogoutServlet
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class LogoutServlet
*/
@WebServlet("/LogoutServlet")
public class LogoutServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public LogoutServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.getSession().removeAttribute("user");
response.sendRedirect("login.jsp");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
VerifyCodeServlet
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* @description 验证码请求生成处理类
* @author WANGZIC
*/
@WebServlet("/VerifyCodeServlet")
public class VerifyCodeServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
VerifyCode vc = new VerifyCode();
request.getSession().setAttribute("sessionverify", vc.getText());
vc.outputImage(90,35,response.getOutputStream());
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
/**
* 验证码生成工具内部类
* @author WANGZIC
*
*/
static class VerifyCode {
private static final char[] CHARS = { '2', '3', '4', '5', '6', '7', '8','9',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M',
'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
private static Random random = new Random();
private String text ;
public String getText() {
StringBuffer buffer = new StringBuffer();
for (int i = 0; i < 4; i++) {
buffer.append(CHARS[random.nextInt(CHARS.length)]);
}
text = buffer.toString();
return text;
}
public void outputImage(int width,int height,OutputStream out) throws IOException{
Color color = new Color(random.nextInt(255), random.nextInt(255), random.nextInt(255));
Color reverse = new Color(255 - color.getRed(), 255 - color.getGreen(), 255 - color.getBlue());
BufferedImage bi = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
Graphics2D g = bi.createGraphics();
g.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 25));
g.setColor(color);
g.fillRect(0, 0, width, height);
g.setColor(reverse);
g.drawString(text, 10, 26);
for (int i = 0, n = random.nextInt(80); i < n; i++) {
g.drawRect(random.nextInt(width), random.nextInt(height), 1, 1);
}
ImageIO.write(bi, "JPEG", out);
}
}
}User
public class User {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
UserDao
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.wzc.login.domain.User;
/**
* @description 数据库连接与操作类用于增删改查数据并返回给servlet使用
* @author WANGZIC
*
*/
public class UserDao {
/*
* 数据库中运行下面的语句
CREATE TABLE `user` (
`username` varchar(255) NOT NULL,
`password` varchar(255) DEFAULT NULL,
PRIMARY KEY (`username`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
*/
//根据用户名查找用户密码
public User findUser(String username){
String sql = "select * from user where username=?";
Connection con =getConnection();
PreparedStatement pstmt =null;
ResultSet rs = null;
User user = new User();
try {
pstmt = con.prepareStatement(sql);
pstmt.setString(1, username);
rs = pstmt.executeQuery();
if(rs.next()){
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
}
} catch (SQLException e) {
e.printStackTrace();
}finally {
try {
if(pstmt!=null)pstmt.close();
if(con!=null)con.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
return user;
}
//添加用户
public boolean addUser(String username,String psw){
Connection con = getConnection();
PreparedStatement pstmt =null;
String sql = "INSERT INTO user(username,password) VALUES(?,?)";
boolean res = false;
try {
pstmt = con.prepareStatement(sql);
pstmt.setString(1, username);
pstmt.setString(2, psw);
res = (pstmt.executeUpdate()==1);
}catch (SQLException e) {
if(!e.getMessage().contains("PRIMARY")){
e.printStackTrace();
}
}finally {
try {
if(pstmt!=null)pstmt.close();
if(con!=null)con.close();
}catch (SQLException e) {
e.printStackTrace();
}
}
return res;
}
//获得连接
public static Connection getConnection(){
String driver ="com.mysql.jdbc.Driver";//记得依赖mysql-jdbc驱动包
String url ="jdbc:mysql://localhost:3306/mytest";//修改为自己的数据库
String user ="root";//修改未自己数据库的用户名密码
String password ="root";//修改未自己数据库的名密码
Connection connection =null;
try {
Class.forName(driver);
connection =DriverManager.getConnection(url, user, password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return connection;
}
public static void main(String[] args) {
//测试方法
// System.out.println(new UserDao().findUser("123"));
// new UserDao().addUser("1345", "1345");
}
}
新增了用户管理功能（对用户的增删改查）
有问题可以加QQ群：483411192
源码下载 下载完源码之后请仔细阅读README.md文件，导入运行步骤和数据库表结构都在里面
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