Eclipse使用（七）—— 使用Eclipse建立JavaWeb專案並使用JDBC連線資料庫實現簡單的登陸註冊功能
阿新 • • 發佈：2019-02-02
一、建立資料庫表（這裡使用的是Mysql5.7）
DDL語句如下：- CREATETABLE `tb_user` (
- `u_id` int(11) NOTNULL AUTO_INCREMENT COMMENT '使用者編號',
- `u_username` varchar(30) NOTNULL COMMENT '使用者名稱',
- `u_password` varchar(30) NOTNULL COMMENT '密碼',
- PRIMARYKEY (`u_id`)
-
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
二、專案需要使用的jar示例
三、編寫持久層和業務層程式碼
專案src目錄結構預覽：
1、在src目錄下建立com.mengfei.entity包，並在包中建立實體類User
package com.mengfei.entity; import java.io.Serializable; public class User implements Serializable{ private static final long serialVersionUID = 1L; private Integer uid; private String username; private String password; public Integer getUid() { return uid; } public void setUid(Integer uid) { this.uid = uid; } 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{" + "uid=" + uid + ", username='" + username + '\'' + ", password='" + password + '\'' + '}'; } }
2、在com.mengfei包中建立dao包，並在包中建立類BaseDao
package com.mengfei.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class BaseDao { protected Connection conn; protected PreparedStatement ps; protected ResultSet rs; public Connection getConnection() { try { Class.forName("com.mysql.jdbc.Driver"); conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/demo?useSSL=false", "alex", "123"); //Class.forName("oracle.jdbc.driver.OracleDriver"); //conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl", "alex", "123"); /** * com.mysql.jdbc.Driver是建立連線的驅動類，Oracle使用的是oracle.jdbc.driver.OracleDriver * jdbc:mysql://localhost:3306/demo?useSSL=false是要連線的url地址，Oracle使用的是jdbc:oracle:thin:@localhost:1521:orcl * localhost代表本地連線，如果使用遠端連線則要改成IP地址 * demo是要連線的mysql中資料庫的名字，Oracle中用的是例項orcl * ?useSSL=false是引數，不寫也能連線，Oracle中不需要 * alex是要連線的使用者名稱 * 123是使用者的密碼 */ } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } return conn; } public void closeDB(ResultSet rs, PreparedStatement ps, Connection conn) { try { if (rs != null) { rs.close(); } if (ps != null) { ps.close(); } if (conn != null) { conn.close(); } } catch (SQLException e) { e.printStackTrace(); } } // 測試是否連線上資料庫 public static void main(String[] args) { BaseDao dao = new BaseDao(); System.out.println(dao.getConnection()); } }
3、在com.mengfei.dao包中建立介面UserDao
package com.mengfei.dao;
import com.mengfei.entity.User;
public interface UserDao {
/**
* 使用者註冊
* @param user
* @return
*/
Integer register(User user);
/**
* 使用者登陸
* @param user
* @return
*/
User login(User user);
}
4、在com.mengfei.dao包中建立impl包，並在包中建立類UserDaoImpl，該類繼承BaseDao，實現UserDao
package com.mengfei.dao.impl;
import java.sql.SQLException;
import com.mengfei.dao.BaseDao;
import com.mengfei.dao.UserDao;
import com.mengfei.entity.User;
public class UserDaoImpl extends BaseDao implements UserDao {
@Override
public Integer register(User user) {
int row = 0;
conn = getConnection();
String sql = "insert into tb_user(u_username,u_password) values(?,?)";
try {
ps = conn.prepareStatement(sql);
ps.setString(1, user.getUsername());
ps.setString(2, user.getPassword());
row = ps.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
closeDB(rs, ps, conn);
}
return row;
}
@Override
public User login(User user) {
User u=null;
conn=getConnection();
String sql="select * from tb_user where u_username=? and u_password=?";
try {
ps=conn.prepareStatement(sql);
ps.setString(1, user.getUsername());
ps.setString(2, user.getPassword());
rs = ps.executeQuery();
while(rs.next()){
u=new User();
u.setUid(rs.getInt(1));
u.setUsername(rs.getString(2));
u.setPassword(rs.getString(3));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
closeDB(rs, ps, conn);
}
return u;
}
}
5、在com.mengfei包中建立biz包，並在包中建立介面UserBiz
package com.mengfei.biz;
import com.mengfei.entity.User;
public interface UserBiz {
/**
* 使用者註冊
* @param username
* @param password
* @return
*/
Boolean register(String username, String password);
/**
* 使用者登陸
* @param username
* @param password
* @return
*/
User login(String username, String password);
}
6、在com.mengfei.biz包中建立impl包，並在包中建立類UserBizImpl實現UserBiz
package com.mengfei.biz.impl;
import com.mengfei.biz.UserBiz;
import com.mengfei.dao.UserDao;
import com.mengfei.dao.impl.UserDaoImpl;
import com.mengfei.entity.User;
public class UserBizImpl implements UserBiz {
private UserDao userDao = new UserDaoImpl();
@Override
public Boolean register(String username, String password) {
User user = new User();
user.setUsername(username);
user.setPassword(password);
Integer result = userDao.register(user);
if (result > 0) {
return true;
}
return false;
}
@Override
public User login(String username, String password) {
User user = new User();
user.setUsername(username);
user.setPassword(password);
User u = userDao.login(user);
return u;
}
}
7、在com.mengfei包中建立servlet包，並在包中建立UserServlet
package com.mengfei.servlet;
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.mengfei.biz.UserBiz;
import com.mengfei.biz.impl.UserBizImpl;
import com.mengfei.entity.User;
@WebServlet("/UserServlet")
public class UserServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
UserBiz userBiz=new UserBizImpl();
String username = request.getParameter("username");
String password = request.getParameter("password");
String operate = request.getParameter("operate");
if(!"".equals(username)&&!"".equals(password)&&!"".equals(operate)) {
if("register".equals(operate)) {
Boolean b = userBiz.register(username, password);
if(b) {
request.getRequestDispatcher("success.jsp").forward(request, response);
}else {
response.sendRedirect("index.jsp");
}
}else if("login".equals(operate)) {
User user = userBiz.login(username, password);
if(null!=user) {
request.setAttribute("username", user.getUsername());
request.getRequestDispatcher("success.jsp").forward(request, response);
}else {
response.sendRedirect("index.jsp");
}
}else {
response.sendRedirect("index.jsp");
}
}else {
response.sendRedirect("index.jsp");
}
}
}
四、編寫表現層程式碼（web.xml檔案暫時不用管它）
1、在WebContent目錄中建立js目錄，將jquery-3.2.1.js檔案放進去
2、編寫index.jsp（放在WebContext目錄下）
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script src="js/jquery-3.2.1.js"></script>
</head>
<body>
<form id="form" action="UserServlet" method="post" onsubmit="return checkUser1()">
<input type="hidden" name="operate" id="operate">
帳號：<input type="text" name="username" id="username"><br>
密碼：<input type="password" name="password" id="password"><br>
<input type="submit" value="註冊">
<input id="login" type="button" value="登陸" onclick="checkUser2()">
</form>
</body>
</html>
<script>
//註冊使用表單提交事件進行驗證提交
function checkUser1() {
var username=$('#username').val();
var password=$('#password').val();
if(''==username){
alert('使用者名稱不能為空！');
return false;
}
if(''==password){
alert('密碼不能為空！');
return false;
}
$('#operate').val('register');
return true;
}
//登陸使用單擊事件進行驗證提交
function checkUser2() {
var username=$('#username').val();
var password=$('#password').val();
if(''==username){
alert('使用者名稱不能為空！');
return false;
}
if(''==password){
alert('密碼不能為空！');
return false;
}
$('#operate').val('login');
$('#form').get(0).action='UserServlet';
$('#form').get(0).submit();
}
</script>3、在WebContent目錄下建立success.jsp檔案
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<c:if test="${empty username}">
註冊成功！
</c:if>
<c:if test="${!empty username}">
登陸成功！歡迎 ${username} !
</c:if>
</body>
</html>五、部署測試
1、右鍵點選本地server將專案新增到Tomcat中
2、啟動Tomcat，在瀏覽器中輸入localhost:8080/JDBCJavaWebDemo/index.jsp，顯示如下圖：
OK，到這裡就可以自己進行註冊和登陸測試啦