Jsp+Servlet實現簡單登入註冊查詢
阿新 • • 發佈：2020-10-02
本文例項為大家分享了Jsp+Servlet實現簡單登入註冊查詢的具體程式碼，供大家參考，具體內容如下
1、註冊功能：
製作一個註冊頁面
使用者輸入：
使用者名稱
密碼
年齡
註冊成功：——>跳轉至登入頁面進行登入
註冊失敗：——>文字或其他形式的提示皆可
2、簡易查詢：
製作一個查詢頁面
輸入使用者名稱
顯示該使用者的使用者名稱、密碼、年齡
演示
1.啟動進入登陸頁面
2.點選註冊，進入註冊頁面,成功跳轉到登入頁面
失敗則提示
回到登入頁面，登入成功進入查詢頁面
登入失敗顯示提示資訊
輸入使用者名稱->顯示該使用者的使用者名稱、密碼、年齡
程式碼
dao
public class UserDao {
private Connection conn = null;
private PreparedStatement ps=null;
private int result=0;
private ResultSet rs=null;
//使用者註冊
public int register(User user){
String sql="insert into users(name,password,age) value (?,?,?)";
try {
//獲取資料庫連線物件
conn= JDBCUtil.getConnection();
//獲取資料庫操作物件
ps=conn.prepareStatement(sql);
ps.setString(1,user.getName());
ps.setString(2,user.getPassword());
ps.setInt(3,user.getAge());
//執行sql
result=ps.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
}finally {
JDBCUtil.close(null,ps,conn);
}
return result;
}
//登入驗證使用者資訊
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,conn);
}
return result;
}
//根據使用者名稱 顯示使用者名稱、密碼、年齡
public User findByName(String userName){
String sql="select name,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,age);
}
} catch (Exception e) {
e.printStackTrace();
}finally {
JDBCUtil.close(null,conn);
}
return user;
}
}entity 實體類
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();
// 註冊
@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);
}
// 根據使用者名稱查詢資訊
@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,IOException {
//1 獲取
String userName = request.getParameter("userName");
String password = request.getParameter("password");
//2 service呼叫dao對資料庫操作
UserService userService = new UserServiceImpl();
int result = userService.login(userName,password);
//3 成功跳轉到查詢頁面，失敗跳轉到失敗頁面
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,IOException {
UserService userService = new UserServiceImpl();
User user = null;
int result = 0;
//1【呼叫請求物件】讀取【請求頭】引數資訊，得到使用者註冊資訊
String userName,age;
userName = request.getParameter("userName");
password = request.getParameter("password");
age = request.getParameter("age");
user = new User(userName,Integer.valueOf(age));
//2 呼叫userService——>userDao
// 先查詢使用者是否存在
User byName = userService.findByName(userName);
if (byName!=null){
request.setAttribute("info","使用者已存在！");
request.getRequestDispatcher("/jsp/register.jsp").forward(request,response);
}
// 註冊
result = userService.register(user);
//3 設定編碼格式，防止亂碼
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
//註冊成功：——>跳轉至登入頁面進行登入
//註冊失敗：——>註冊頁面提示：註冊失敗
if (result == 1) {
response.sendRedirect("/login.html");
} else {
request.setAttribute("info","註冊失敗！");
request.getRequestDispatcher("/jsp/register.jsp").forward(request,response);
}
}
}
JDBCUtil
public class JDBCUtil {
private JDBCUtil(){}
//靜態程式碼塊在類載入時執行，並且執行一次。
static{
try {
Class.forName("com.mysql.cj.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
//獲取資料庫連線物件
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);
}
/**
*關閉資源
* @param conn 連線物件
* @param ps 資料庫操作物件
* @param rs 結果集
*/
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">
<h2/>輸入使用者名稱，查詢資訊
<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>使用者名稱</th>
<th>密碼</th>
<th>年齡</th>
</tr>
<tr>
<td> <%=userInfo.getName()%> </td>
<td> <%=userInfo.getPassword()%> </td>
<td> <%=userInfo.getAge()%> </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)){
%>
<h1 style="color: red;text-align: center" ><%=info%></h1>
<%
}
%>
<div align="center">
<form action="/register" method="post">
<table border="2">
<tr>
<th>使用者名稱</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="註冊"/>
<input type="reset" value="清空"/>
</td>
</tr>
</table>
</form>
</div>
</body>
</html>
web.xml
<?xml version="1.0" encoding="UTF-8"?> <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> <!--設定預設歡迎檔案規則--> <welcome-file-list> <welcome-file>login.html</welcome-file> <!--servlet 作為預設歡迎檔案 ‘/'需要去掉--> </welcome-file-list> </web-app>
login.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>登陸介面</title>
</head>
<body>
<div align="center">
<font size="10px" color="#00008b">使用者登入</font>
<form action="/login" method="post">
<table border="2">
<tr>
<th>使用者名稱</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="登入"/>
<input type="reset" />
</td>
</tr>
</table>
</form>
<a href="/jsp/register.jsp" rel="external nofollow" rel="external nofollow" style="text-align: left">立即註冊</a>
</div>
</body>
</html>
login_error.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>登入驗證</title>
</head>
<body>
<div align="center">
<font size="10px" color="#00008b">使用者登入</font><br>
<font size="5px" color="red">登入資訊不存在，請重新登陸！！！</font>
<form action="/login" method="post">
<table border="2">
<tr>
<th>使用者名稱</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="登入"/>
<input type="reset">
</td>
</tr>
</table>
</form>
<a href="/jsp/register.jsp" rel="external nofollow" rel="external nofollow" style="text-align: left">立即註冊</a>
</div>
</body>
</html>
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。