JavaWeb簡(jiǎn)單用戶登錄注冊(cè)實(shí)例代碼(有驗(yàn)證碼)

更新時(shí)間：2020年02月27日 11:01:42 作者：lungggg

這篇文章主要介紹了JavaWeb簡(jiǎn)單用戶登錄注冊(cè)實(shí)例代碼，文中通過示例代碼介紹的非常詳細(xì)，對(duì)大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值，需要的朋友們下面隨著小編來一起學(xué)習(xí)學(xué)習(xí)吧

需求

編寫login登錄界面(用戶名，密碼，驗(yàn)證碼，登陸按鈕，注冊(cè)按鈕)
設(shè)計(jì)關(guān)系數(shù)據(jù)庫(編號(hào)，用戶名，密碼)
編寫注冊(cè)功能，將數(shù)據(jù)存儲(chǔ)在數(shù)據(jù)庫中。（姓名不能重復(fù)，設(shè)為主鍵，重復(fù)會(huì)注冊(cè)失?。?/li>
編寫登錄功能。首先獲取驗(yàn)證碼，先判斷驗(yàn)證碼是否正確，不正確則顯示驗(yàn)證碼錯(cuò)誤。驗(yàn)證碼正確后再獲取用戶名和密碼，進(jìn)行數(shù)據(jù)庫的搜索比對(duì)，若正確則重定向到成功的界面，并且將用戶名顯示。

jar包

技術(shù)選型
Servlet + JSP + Mysql + JDBCTemplate + Druid + BeanUtils + Tomcat

效果圖

驗(yàn)證碼或者用戶名和密碼錯(cuò)誤

Navicat Premium 顯示Mysql內(nèi)容

登錄成功

注冊(cè)功能

源碼

登錄主界面 login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
  <title>Login</title>

  <script>
  <%-- 增加時(shí)間戳來更換驗(yàn)證碼圖片 --%>
    window.onload=function(){
      document.getElementById("img").onclick=function(){
        this.src = "/daydayup/checkCodeServlet?time" + new Date().getTime();
      }
    }
    
<%-- 用于打開注冊(cè)的窗口--%>
    function reg() {
      window.open("register.jsp");
    }
  </script>
  <style>
    div{
      color: red;
    }
  </style>
</head>
<body>

<form action="/daydayup/loginServlet" method="post">
  <table>
    <tr>
      <td>用戶名</td>
      <td><input type="text" name="username"></td>
    </tr>
    <tr>
      <td>密碼</td>
      <td><input type="text" name="password"></td>
    </tr>
    <tr>
      <td>驗(yàn)證碼</td>
      <td><input type="text" name="checkcode"></td>
    </tr>
    <tr>
      <td colspan="2"><img id="img" src="/daydayup/checkCodeServlet" alt=""></td>
    </tr>
    <tr>
      <td><input type="submit" value="登錄"></td>
      <td><input type="button" value="注冊(cè)" onclick="reg()" ></td>

    </tr>
  </table>
</form>

<div>${requestScope.login_error}</div>
<div>${requestScope.checkcode_error}</div>
</body>
</html>

注冊(cè)界面 register.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
  <title>Title</title>
</head>
<body>
<form action="/daydayup/registerServlet" method="post">
  <table>
    <tr>
      <td>用戶名</td>
      <td><input type="text" name="username"></td>
    </tr>
    <tr>
      <td>密碼</td>
      <td><input type="text" name="password"></td>
    </tr>
    <tr>
      <td><input type="submit" value="確定注冊(cè)"></td>
    </tr>
  </table>
</form>
<div>${requestScope.register_success}</div>
<div>${requestScope.register_error}</div>
</body>
</html>

成功界面 success.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
  <title>Title</title>
</head>
<body>
<%--  <h1>${requestScope.user},歡迎您</h1>  --%>
  <h1><%=request.getSession().getAttribute("user")%>,歡迎您</h1>
</body>
</html>

先編輯好JDBCUtils工具類

package cn.code.util;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

/**
 * JDBC工具類 使用Durid連接池
 */
public class JDBCUtils {

  private static DataSource ds;

  static{
    try {
      //加載配置文件
      Properties pro = new Properties();
      //使用ClassLoader加載配置文件，獲取字節(jié)輸入流
      InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties");
      pro.load(is);

      //初始化連接池對(duì)象
      ds = DruidDataSourceFactory.createDataSource(pro);
    } catch (Exception e) {
      e.printStackTrace();
    }


  }

  /**
   * 獲取連接池對(duì)象
   */
  public static DataSource getDataSource(){
    return ds;
  }
  /**
   * 獲取連接connection對(duì)象
   */
  public static Connection getConnection() throws SQLException {
    return ds.getConnection();
  }
}

創(chuàng)建我們的用戶類實(shí)體User

package cn.code.domain;

/*
用戶的實(shí)體類
 */

public class User {
  private int id ;
  private String username;
  private String password;

  public int getId() {
    return id;
  }

  public void setId(int id) {
    this.id = id;
  }

  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;
  }

  @Override
  public String toString() {
    return "User{" +
        "id=" + id +
        ", username='" + username + '\'' +
        ", password='" + password + '\'' +
        '}';
  }
}

編寫Dao來操作數(shù)據(jù)庫，里面有l(wèi)ogin和add兩個(gè)方法 Userdao

package cn.code.dao;

import cn.code.domain.User;
import cn.code.util.JDBCUtils;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * 操作數(shù)據(jù)庫中User表的類
 */
public class UserDao {

  //聲明JDBCTemplate對(duì)象，以便方法公用
  private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());

  /**
   * 登錄方法
   *
   * @param loginUser 目前只有用戶名和密碼
   * @return user包含用戶全部數(shù)據(jù)
   */
  public User login(User loginUser) {
    //編寫SQL
    String sql = "select * from user where username = ? and password = ?";
    //調(diào)用query方法
    try {
      User user = template.queryForObject(sql,
          new BeanPropertyRowMapper<User>(User.class),
          loginUser.getUsername(), loginUser.getPassword());
      return user;
    } catch (DataAccessException e) {
      e.printStackTrace();
      return null;
    }
  }

  /**
   * 注冊(cè)方法
   *
   * @param user 目前只包含用戶名和密碼
   * @return 是否注冊(cè)成功
   */
  public boolean add(User user){
    //編寫SQL
    String sql = "insert into user (username,password) VALUES('" + user.getUsername() + "','" + user.getPassword() + "')";
    boolean flag = false;
    int num = 0;
    try {
      //創(chuàng)建數(shù)據(jù)庫連接
      Connection conn = JDBCUtils.getConnection();
      Statement state = null;
      flag = false;
      num = 0;

      state = conn.createStatement();
      num = state.executeUpdate(sql);
    } catch (SQLException e) {
      e.printStackTrace();
    }

    if(num >0) flag = true;
    return flag;
  }
}

登錄的Servlet

package cn.code.servlet;

import cn.code.dao.UserDao;
import cn.code.domain.User;

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 javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    //設(shè)置字符編碼
    request.setCharacterEncoding("utf-8");
    //獲取參數(shù)
    String username = request.getParameter("username");
    String password = request.getParameter("password");
    String checkcode = request.getParameter("checkcode");
    //獲取生成的驗(yàn)證碼
    HttpSession session = request.getSession();
    String checkcode_session =(String) session.getAttribute("checkcode_session");
    //防止驗(yàn)證碼存儲(chǔ) 刪除Session中存儲(chǔ)的驗(yàn)證碼
    session.removeAttribute("checkcode_session");

    //判斷驗(yàn)證碼是否正確
    if(checkcode_session != null && checkcode_session.equalsIgnoreCase(checkcode)){
      //equalsIgnoreCase忽略大小寫的比較
      //驗(yàn)證碼正確
      User loginUser = new User();
      loginUser.setUsername(username);
      loginUser.setPassword(password);
      User user = new UserDao().login(loginUser);

      if(user != null){
        //用戶名以及密碼正確
        //登錄成功
        //存儲(chǔ)用戶信息
        session.setAttribute("user",username); //因?yàn)槭莾纱握?qǐng)求，所以用Session
        //重定向到success.jsp
        response.sendRedirect(request.getContextPath()+"/success.jsp");
      }else{
        //用戶名及密碼錯(cuò)誤
        //登錄失敗
        //存儲(chǔ)提示信息到request
        request.setAttribute("login_error","用戶名或密碼錯(cuò)誤");
        //轉(zhuǎn)發(fā)到登錄頁面
        request.getRequestDispatcher("/login.jsp").forward(request,response);
      }
    }else{
      //驗(yàn)證碼不正確
      //存儲(chǔ)提示信息到request
      request.setAttribute("checkcode_error","驗(yàn)證碼錯(cuò)誤");
      //轉(zhuǎn)發(fā)到登錄頁面
      request.getRequestDispatcher("/login.jsp").forward(request,response);
    }

  }

  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    this.doPost(request, response);
  }
}

注冊(cè)的Servlet

package cn.code.servlet;

import cn.code.dao.UserDao;
import cn.code.domain.User;

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 java.io.IOException;

@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {
  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("utf-8");

    String username = request.getParameter("username");
    String password = request.getParameter("password");

    User registerUser = new User();
    registerUser.setUsername(username);
    registerUser.setPassword(password);
    boolean flag = new UserDao().add(registerUser);
    if(flag) {
      request.setAttribute("register_success","注冊(cè)成功");
      request.getRequestDispatcher("/register.jsp").forward(request,response);
    }else{
      request.setAttribute("register_error","賬號(hào)以被注冊(cè),注冊(cè)失敗");
      request.getRequestDispatcher("/register.jsp").forward(request,response);
    }

  }

  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    this.doPost(request,response);
  }
}

在頁面中畫驗(yàn)證碼（可點(diǎn)擊更換）Servlet

package cn.code.checkcode;

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;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

//簡(jiǎn)易驗(yàn)證碼
@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    int width = 100;
    int height = 50;
    //創(chuàng)建一對(duì)象，在內(nèi)存中代表圖片（驗(yàn)證碼圖片對(duì)象）
    BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_BGR);

    //美化圖片
    //填充背景色
    Graphics g = image.getGraphics();//畫筆對(duì)象
    g.setColor(Color.ORANGE);
    g.fillRect(0,0,width,height);
    //畫邊框
    g.setColor(Color.BLUE);
    g.drawRect(0,0,width-1,height-1);

    String str = "QWERTYUIOPASDFGHJKLZXCVBNM1234567890zxcvbnmlkjhgfdsaqwertyuiop";

    //生成隨機(jī)角標(biāo)
    StringBuilder sb = new StringBuilder();
    Random ran = new Random();
    for (int i = 1; i <= 4; i++) {
      int index = ran.nextInt(str.length());
      //獲取字符
      char ch = str.charAt(index);
      sb.append(ch);
      //寫驗(yàn)證碼
      g.drawString(ch+"",width/5*i,height/2);
    }
    String checkcode_session = sb.toString();
    //將驗(yàn)證碼存入session
    request.getSession().setAttribute("checkcode_session",checkcode_session);

    //畫干擾線
    g.setColor(Color.RED);
    //隨機(jī)生成坐標(biāo)點(diǎn)
    for (int i = 0 ;i<6;i++) {
      int x1 = ran.nextInt(width);
      int x2 = ran.nextInt(width);
      int y1 = ran.nextInt(height);
      int y2 = ran.nextInt(height);
      g.drawLine(x1,y1,x2,y2);
    }
    //將圖片輸出到頁面展示
    ImageIO.write(image, "jpg", response.getOutputStream());
  }

  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    this.doPost(request, response);
  }
}

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