用servlet寫的學生登入註冊
阿新 • • 發佈：2018-12-30
①資料庫
CREATE TABLE `member` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(20) NOT NULL,
`pass` varchar(20) NOT NULL,
`age` int(3) DEFAULT NULL,
`sex` varchar(2) DEFAULT NULL,
`hobby` varchar(20) DEFAULT NULL COMMENT '愛好',
`ipaddr` varchar(20) DEFAULT NULL,
`sheng` varchar(10) DEFAULT ②首頁：
<body>
<h1>學生管理系統</h1>
<form action="login" method="post">
<table>
<tr>
<td>使用者名稱：</td>
<td><input type="text" name="username"></td>
</tr ③註冊：
<body>
<h1>使用者註冊</h1>
<form action="reg" method="post">
使用者名稱：<input type="text" name="username"><br>
密碼:<input type="password" name="pass"><br>
重複密碼：<input type="password" name="pass2"><br>
年齡：<input type="text" name="age"><br>
性別：男<input type="radio" name="sex" value="男">
女<input type="radio" name="sex" value="女">
<br>
愛好：
旅遊 <input type="checkbox" name="hobby" value="旅遊">
程式設計 <input type="checkbox" name="hobby" value="程式設計">
美食 <input type="checkbox" name="hobby" value="美食">
<br>
所在省份：<select name="sheng">
<option value="湖北">湖北</option>
<option value="湖南">湖南</option>
<option value="河北">河北</option>
<option value="河南">河南</option>
</select><br>
個人簡介：<textarea rows="6" cols="35" name="info"></textarea>
<br>
<input type="submit" value="註冊">
</form>
</body>④連線資料庫的工具類:
package com.bright;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class JDBCUtil {
private String url; //url地址
private String dbuser; //資料庫的使用者名稱
private String dbpass; //資料庫的登入密碼
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getDbuser() {
return dbuser;
}
public void setDbuser(String dbuser) {
this.dbuser = dbuser;
}
public String getDbpass() {
return dbpass;
}
public void setDbpass(String dbpass) {
this.dbpass = dbpass;
}
public JDBCUtil() {
super();
}
public JDBCUtil(String url, String dbuser, String dbpass) {
super();
this.url = url;
this.dbuser = dbuser;
this.dbpass = dbpass;
}
//靜態程式碼塊，載入驅動
static{
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
//對外提供一個連線資料庫的方法
public Connection getConnection() throws Exception{
return DriverManager.getConnection(this.url, this.dbuser, this.dbpass);
}
}
⑤定義一個使用者類：
package com.bright;
public class User {
private int id;
private String username;
private String pass;
private int age;
private String sex;
private String hobby;
private String sheng;
private String ipaddr;
private String info;
public User() {
super();
}
public User(String username, String pass, int age, String sex,
String hobby, String sheng, String ipaddr, String info) {
super();
this.username = username;
this.pass = pass;
this.age = age;
this.sex = sex;
this.hobby = hobby;
this.sheng = sheng;
this.ipaddr = ipaddr;
this.info = info;
}
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 getPass() {
return pass;
}
public void setPass(String pass) {
this.pass = pass;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getHobby() {
return hobby;
}
public void setHobby(String hobby) {
this.hobby = hobby;
}
public String getSheng() {
return sheng;
}
public void setSheng(String sheng) {
this.sheng = sheng;
}
public String getIpaddr() {
return ipaddr;
}
public void setIpaddr(String ipaddr) {
this.ipaddr = ipaddr;
}
public String getInfo() {
return info;
}
public void setInfo(String info) {
this.info = info;
}
}
⑥使用者類的處理：
package com.bright;
import java.sql.*;
//註冊的時候儲存使用者（通過使用者的id）
public class UserDao {
//因為這個操作類就是對資料庫進行操作，所有要連線資料庫
private JDBCUtil util;
public JDBCUtil getUtil() {
return util;
}
public void setUtil(JDBCUtil util) {
this.util = util;
}
//
public void saveUser(User user){
Connection conn = null;
PreparedStatement stat = null;
try {
String sql = "insert into member values (null,?,?,?,?,?,?,?,?)";
conn = util.getConnection(); //建立連線
stat = conn.prepareStatement(sql); //建立預處理物件
//儲存資料（有幾個問好，就存幾個）
stat.setString(1, user.getUsername());
stat.setString(2, user.getPass());
stat.setInt(3, user.getAge());
stat.setString(4, user.getSex());
stat.setString(5, user.getHobby());
stat.setString(6, user.getIpaddr());
stat.setString(7, user.getSheng());
stat.setString(8, user.getInfo());
stat.executeUpdate();//儲存
} catch (Exception e) {
e.printStackTrace();
}finally{
try {
if(conn!=null&!conn.isClosed()){
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
//登入時，通過使用者名稱找到這個物件，因為查詢到的是一個物件，所有返回一個user
public User getUserByName(String uname){
User user = null;
Connection conn = null;
PreparedStatement stat = null;
ResultSet res = null;
try {
String sql = "select * from member where username = ?";
conn = util.getConnection();
stat = conn.prepareStatement(sql);
stat.setString(1, uname);
//把查詢到的資料放到結果集中
res = stat.executeQuery();//查詢
//如果查詢到，就將結果集中的資料儲存到使用者中
if(res.next()){
user = new User();
user.setId(res.getInt("id"));
user.setAge(res.getInt("age"));
user.setUsername(res.getString("username"));
user.setPass(res.getString("pass"));
}
} catch (Exception e) {
e.printStackTrace();
}finally{
try {
if(conn!=null&!conn.isClosed()){
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
return user;
}
}
⑦處理登入：
package com.bright;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
//獲取請求引數
req.setCharacterEncoding("utf8");
String username = req.getParameter("username");
String pass = req.getParameter("pass");
resp.setContentType("text/html;charset=utf8");
PrintWriter out = resp.getWriter();
//如果使用者名稱和密碼不為空，並且長度大於0就執行if語句--->判斷查詢到的user--->判斷密碼是否一致
if(username!=null&&username.length()>0&&pass!=null&&pass.length()>0){
//要連線資料庫，先從配置表中獲取初始化引數傳給JDBSUtil的建構函式
ServletContext ctx = this.getServletContext();
String url = ctx.getInitParameter("url");
String dbuser = ctx.getInitParameter("dbuser");
String dbpass = ctx.getInitParameter("dbpass");
JDBCUtil util = new JDBCUtil(url, dbuser, dbpass);
//然後將util作為引數傳給操作類
UserDao dao = new UserDao();
dao.setUtil(util);
//呼叫操作類的通過使用者名稱查詢使用者
User user = dao.getUserByName(username);
if(user!=null){
if(user.getPass().equals(pass)){
out.println("<h1>恭喜你！登入成功！進入了學生管理系統！</h1>");
}else{
out.println("<h1>登入失敗！密碼錯誤！</h1>");
out.println("<br><a href='index.jsp'>點此登入</a>");
}
}else{
out.println("<h1>登入失敗！使用者名稱錯誤！</h1>");
out.println("<br><a href='index.jsp'>點此登入</a>");
}
}else{
out.println("<h1>登入失敗！使用者名稱/密碼錯誤！</h1>");
out.println("<br><a href='index.jsp'>點此登入</a>");
}
out.flush();
out.close();
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(req, resp);
}
}
⑧處理註冊：
package com.bright;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class RegServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
//提交方式為post
req.setCharacterEncoding("utf8");
//接收請求中的引數
String username = req.getParameter("username");
String pass = req.getParameter("pass");
String pass2 = req.getParameter("pass2");
String age = req.getParameter("age");
String sex = req.getParameter("sex");
String[] hobbys = req.getParameterValues("hobby");
String hobby = "";
for(int i=0;i<hobbys.length;i++){
if(i!=hobbys.length-1){
hobby += hobbys[i]+",";
}else{
hobby += hobbys[i];
}
}
String sheng = req.getParameter("sheng");
String info = req.getParameter("info");
String ipaddr = req.getRemoteAddr();
int iage = -1;
try {
iage = Integer.parseInt(age);
} catch (NumberFormatException e) {
e.printStackTrace();
}
resp.setContentType("text/html;charset=utf8");
PrintWriter out = resp.getWriter();
//輸入校驗
if(username!=null&&username.length()>5&&pass!=null&&pass.length()>5&&pass.equals(pass2)&&iage>=0){
//要連線資料庫，先從配置表中獲取初始化引數傳給JDBSUtil的建構函式
ServletContext ctx = this.getServletContext();
String url = ctx.getInitParameter("url");
String dbuser = ctx.getInitParameter("dbuser");
String dbpass = ctx.getInitParameter("dbpass");
JDBCUtil util = new JDBCUtil(url, dbuser, dbpass);
//userdao--->util--->資料庫
//然後將util作為引數傳給操作類
UserDao dao = new UserDao();
dao.setUtil(util);
//將獲取的的引數存到uer中，呼叫操作類中的方法儲存
User user = new User(username, pass, iage, sex, hobby, sheng, ipaddr, info);
dao.saveUser(user);
out.println("<h1>恭喜你！註冊成功</h1>");
out.println("<br><a href='index.jsp'>點此登入</a>");
}else{
out.println("<h1>引數有誤，註冊失敗！</h1>");
out.println("<br><a href='reg.html'>重新註冊</a>");
}
out.flush();
out.close();
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(req, resp);
}
}
⑨配置資訊：
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<display-name></display-name>
<context-param>
<param-name>url</param-name>
<param-value>jdbc:mysql:///servlet</param-value>
</context-param>
<context-param>
<param-name>dbuser</param-name>
<param-value>root</param-value>
</context-param>
<context-param>
<param-name>dbpass</param-name>
<param-value>123</param-value>
</context-param>
<servlet>
<servlet-name>RegServlet</servlet-name>
<servlet-class>com.bright.RegServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RegServlet</servlet-name>
<url-pattern>/reg</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>com.bright.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>