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使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢

發(fā)布時間：2020-10-31 01:36:25 來源：億速云 閱讀：351 作者：Leah 欄目：開發(fā)技術(shù)

這篇文章將為大家詳細(xì)講解有關(guān)使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢，文章內(nèi)容質(zhì)量較高，因此小編分享給大家做個參考，希望大家閱讀完這篇文章后對相關(guān)知識有一定的了解。

1、注冊功能：

制作一個注冊頁面
用戶輸入：

用戶名
密碼
年齡
注冊成功：——>跳轉(zhuǎn)至登錄頁面進(jìn)行登錄
注冊失?。骸?gt;文字或其他形式的提示皆可

2、簡易查詢：

制作一個查詢頁面
輸入用戶名
顯示該用戶的用戶名、密碼、年齡

演示

1.啟動進(jìn)入登陸頁面

使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢

2.點(diǎn)擊注冊，進(jìn)入注冊頁面,成功跳轉(zhuǎn)到登錄頁面

使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢

失敗則提示

使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢

回到登錄頁面，登錄成功進(jìn)入查詢頁面

使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢

登錄失敗顯示提示信息

使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢

輸入用戶名->顯示該用戶的用戶名、密碼、年齡

使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢

代碼

使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢

dao

public class UserDao {
 private Connection conn = null;
 private PreparedStatement ps=null;
 private int result=0;
 private ResultSet rs=null;

 //用戶注冊
 public int register(User user){
 String sql="insert into users(name,password,age) value (?,?,?)";
 try {
  //獲取數(shù)據(jù)庫連接對象
  conn= JDBCUtil.getConnection();
  //獲取數(shù)據(jù)庫操作對象
  ps=conn.prepareStatement(sql);
  ps.setString(1,user.getName());
  ps.setString(2,user.getPassword());
  ps.setInt(3,user.getAge());
  //執(zhí)行sql
  result=ps.executeUpdate();
 } catch (Exception e) {
  e.printStackTrace();
 }finally {
  JDBCUtil.close(null,ps,conn);
 }
 return result;
 }

 //登錄驗(yàn)證用戶信息
 public int login(String userName,String password){
 String sql ="select count(*) from users where name=? and password=?";
 try {
  conn=JDBCUtil.getConnection();
  ps=conn.prepareStatement(sql);
  ps.setString(1,userName);
  ps.setString(2,password);
  rs=ps.executeQuery();
  while (rs.next()){
  result=rs.getInt("count(*)");
  }
 } catch (Exception e) {
  e.printStackTrace();
 } finally {
  JDBCUtil.close(rs,ps,conn);
 }
 return result;
 }

 //根據(jù)用戶名 顯示用戶名、密碼、年齡
 public User findByName(String userName){
 String sql="select name,password,age from users where name=?";
 User user = null;
 try {
  conn=JDBCUtil.getConnection();
  ps=conn.prepareStatement(sql);
  ps.setString(1,userName);
  rs=ps.executeQuery();
  while (rs.next()){
  String name = rs.getString("name");
  String password = rs.getString("password");
  int age = rs.getInt("age");
  user = new User(name,password,age);
  }

 } catch (Exception e) {
  e.printStackTrace();
 }finally {
  JDBCUtil.close(null,ps,conn);
 }
 return user;
 }
}

entity 實(shí)體類

public class User {
 private int id;
 private String name;
 private String password;
 private int age;
//set...
//get...
//constructor...
}

service

public class UserServiceImpl implements UserService {
 UserDao userDao = new UserDao();
 // 注冊
 @Override
 public int register(User user) {
 return userDao.register(user);
 }
 // 登陸
 @Override
 public int login(String userName, String password) {
 return userDao.login(userName,password);
 }

 // 根據(jù)用戶名查找信息
 @Override
 public User findByName(String userName) {
 return userDao.findByName(userName);
 }
}

servlet

// FindByNameServlet
public class FindByNameServlet extends HttpServlet {
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 String name = request.getParameter("name");

 UserService userService = new UserServiceImpl();
 User user = userService.findByName(name);

 //將查詢結(jié)果放入request作用域
 request.setAttribute("userInfo",user);
 request.getRequestDispatcher("/jsp/index.jsp").forward(request,response);
 }
}

// LoginServlet
public class LoginServlet extends HttpServlet {
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 //1 獲取
 String userName = request.getParameter("userName");
 String password = request.getParameter("password");

 //2 service調(diào)用dao對數(shù)據(jù)庫操作
 UserService userService = new UserServiceImpl();
 int result = userService.login(userName, password);

 //3 成功跳轉(zhuǎn)到查詢頁面，失敗跳轉(zhuǎn)到失敗頁面
 if (result>0){
  response.sendRedirect("/jsp/index.jsp");
 }else{
  response.sendRedirect("/login_error.html");
 }
 }
}
// RegisterServlet
public class RegisterServlet extends HttpServlet {
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 UserService userService = new UserServiceImpl();
 User user = null;
 int result = 0;
 //1【調(diào)用請求對象】讀取【請求頭】參數(shù)信息，得到用戶注冊信息
 String userName, password, age;
 userName = request.getParameter("userName");
 password = request.getParameter("password");
 age = request.getParameter("age");
 user = new User(userName, password, Integer.valueOf(age));
 //2 調(diào)用userService——>userDao
 // 先查詢用戶是否存在
 User byName = userService.findByName(userName);
 if (byName!=null){
  request.setAttribute("info","用戶已存在！");
  request.getRequestDispatcher("/jsp/register.jsp").forward(request,response);
 }
 // 注冊
 result = userService.register(user);

 //3 設(shè)置編碼格式，防止亂碼
 response.setContentType("text/html;charset=utf-8");
 PrintWriter out = response.getWriter();

 //注冊成功：——>跳轉(zhuǎn)至登錄頁面進(jìn)行登錄
 //注冊失?。骸?gt;注冊頁面提示：注冊失敗
 if (result == 1) {
  response.sendRedirect("/login.html");
 } else {
  request.setAttribute("info","注冊失??！");
  request.getRequestDispatcher("/jsp/register.jsp").forward(request,response);
 }
 }
}

JDBCUtil

public class JDBCUtil {
 private JDBCUtil(){}
 //靜態(tài)代碼塊在類加載時執(zhí)行，并且執(zhí)行一次。
 static{
 try {
  Class.forName("com.mysql.cj.jdbc.Driver");
 } catch (ClassNotFoundException e) {
  e.printStackTrace();
 }
 }
 //獲取數(shù)據(jù)庫連接對象
 public static Connection getConnection() throws Exception{
 String url="jdbc:mysql://127.0.0.1:3306/zy?&useSSL=false&serverTimezone=UTC&rewriteBatchedStatements=true";
 String user="root";
 String password="rootroot";

 return DriverManager.getConnection(url,user,password);
 }
 /**
 *關(guān)閉資源
 * @param conn 連接對象
 * @param ps 數(shù)據(jù)庫操作對象
 * @param rs 結(jié)果集
 */
 public static void close(ResultSet rs, Statement ps, Connection conn){
 if (rs != null) {
  try {
  rs.close();
  } catch (SQLException e) {
  e.printStackTrace();
  }
 }
 if (ps != null) {
  try {
  ps.close();
  } catch (SQLException e) {
  e.printStackTrace();
  }
 }
 if (conn != null) {
  try {
  conn.close();
  } catch (SQLException e) {
  e.printStackTrace();
  }
 }
 }
}

index.jsp

<%@ page import="entity.User" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
 <title>查詢頁面</title>
</head>
<body>
<div align="center">
 <h3/>輸入用戶名，查詢信息
 <form action="/findByName" method="get">
 <input type="text" name="name" id="name">
 <input type="submit" value="查詢">
 </form>
 <%
 User userInfo = (User) request.getAttribute("userInfo");
 %>
 <%
 if (userInfo != null) {
 %>
 <table border="3">
 <tr>
  <th>用戶名</th>
  <th>密碼</th>
  <th>年齡</th>
 </tr>
 <tr>
  <td> &nbsp; &nbsp; <%=userInfo.getName()%> &nbsp; &nbsp;</td>
  <td> &nbsp; &nbsp; <%=userInfo.getPassword()%> &nbsp; &nbsp;</td>
  <td> &nbsp; &nbsp; <%=userInfo.getAge()%> &nbsp; &nbsp;</td>
 </tr>

 </table>
 <%
 }
 %>
</div>
</body>
</html>

register.jsp

<%@ page import="com.mysql.cj.util.StringUtils" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
 <title>Title</title>
</head>
<body>
<br>
<br>
<%
 String info =(String) request.getAttribute("info");
%>
<%
 if (!StringUtils.isNullOrEmpty(info)){
%>
 <h2  ><%=info%></h2>
<%
 }
%>

<div align="center">
 <form action="/register" method="post">
 <table border="2">
  <tr>
  <th>用戶名</th>
  <td><input type="text" name="userName"/></td>
  </tr>
  <tr>
  <th>密碼</th>
  <td><input type="password" name="password"/></td>
  </tr>
  <tr>
  <th>年齡</th>
  <td><input type="text" name="age"/></td>
  </tr>
  <tr>
  <td colspan="2" align="center">
   <input type="submit" value="注冊"/>
   <input type="reset" value="清空"/>
  </td>
  </tr>
 </table>
 </form>
</div>
</body>
</html>

web.xml

<&#63;xml version="1.0" encoding="UTF-8"&#63;>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
  version="4.0">
 <servlet>
 <servlet-name>LoginServlet</servlet-name>
 <servlet-class>servlet.LoginServlet</servlet-class>
 </servlet>
 <servlet>
 <servlet-name>RegisterServlet</servlet-name>
 <servlet-class>servlet.RegisterServlet</servlet-class>
 </servlet>
 <servlet>
 <servlet-name>FindByNameServlet</servlet-name>
 <servlet-class>servlet.FindByNameServlet</servlet-class>
 </servlet>
 <servlet-mapping>
 <servlet-name>LoginServlet</servlet-name>
 <url-pattern>/login</url-pattern>
 </servlet-mapping>
 <servlet-mapping>
 <servlet-name>RegisterServlet</servlet-name>
 <url-pattern>/register</url-pattern>
 </servlet-mapping>
 <servlet-mapping>
 <servlet-name>FindByNameServlet</servlet-name>
 <url-pattern>/findByName</url-pattern>
 </servlet-mapping>

 <!--設(shè)置默認(rèn)歡迎文件規(guī)則-->
 <welcome-file-list>
 <welcome-file>login.html</welcome-file> <!--servlet 作為默認(rèn)歡迎文件 ‘/'需要去掉-->
 </welcome-file-list>
</web-app>

login.html

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>登陸界面</title>
</head>
<body>
<div align="center">
 <font size="10px" color="#00008b">用戶登錄</font>
 <form action="/login" method="post">

 <table border="2">
  <tr>
  <th>用戶名</th>
  <td><input type="text" name="userName"/></td>
  </tr>
  <tr>
  <th>密碼</th>
  <td><input type="password" name="password"/></td>
  </tr>
  <tr>
  <td colspan="2" align="center">
   <input type="submit" value="登錄"/>
   <input type="reset" />
  </td>
  </tr>
 </table>
 </form>
 <a href="/jsp/register.jsp" >立即注冊</a>


</div>
</body>
</html>

login_error.html

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>登錄驗(yàn)證</title>
</head>
<body>
<div align="center">
 <font size="10px" color="#00008b">用戶登錄</font><br>
 <font size="5px" color="red">登錄信息不存在，請重新登陸?。?！</font>
 <form action="/login" method="post">
 <table border="2">
  <tr>
  <th>用戶名</th>
  <td><input type="text" name="userName" /></td>
  </tr>
  <tr>
  <th>密碼</th>
  <td><input type="password" name="password" /></td>
  </tr>
  <tr>
  <td colspan="2" align="center">
   <input type="submit" value="登錄"/>
   <input type="reset">

  </td>
  </tr>
 </table>
 </form>
 <a href="/jsp/register.jsp" >立即注冊</a>

</div>
</body>
</html>

關(guān)于使用Jsp+Servlet實(shí)現(xiàn)簡單登錄注冊查詢就分享到這里了，希望以上內(nèi)容可以對大家有一定的幫助，可以學(xué)到更多知識。如果覺得文章不錯，可以把它分享出去讓更多的人看到。

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