2020-12-31 利用現有資料庫用ajax設計登入附帶驗證碼驗證
阿新 • • 發佈：2021-01-01
1.登入頁面的jsp檔案程式碼如下：
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>使用者登入</title> </head> <body> <input type="text" name="username" id="username"><span id="nameerror"></span><br> <input type="password" name="password" id="password"><span id="pwderror"></span><br> <input type="text" name="code" id="code" placeholder="請輸入驗證碼"> <img src="VerfyCodeServlet" onclick="myRefersh(this)"><br> <input type="submit" value="登入" id="bt"><br> </body> <script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script> <script type="text/javascript"> $("#bt").click(function() { $.ajax({ url:"LoginServlet", type:'post', data:{ username:$("#username").val(), password:$("#password").val(), code:$("#code").val() }, success:function(data){ //判斷伺服器返回的資料是否正確 if(data.status=="ok"){ window.location.href="index.jsp"; }else{ $("#nameerror").text(data.msg); } } }); }); $("#username").blur(function() { $.ajax({ url:"ChackServlet", type:'post', data:{ username:$("#username").val() }, success:function(data){ $("#nameerror").text(data.msg); } }); }); function myRefersh( e ) { const source = e.src ; // 獲得原來的 src 中的內容 //console.log( "source : " + source ) ; var index = source.indexOf( "?" ) ; // 從 source 中尋找 ? 第一次出現的位置 (如果不存在則返回 -1 ) //console.log( "index : " + index ) ; if( index > -1 ) { // 如果找到了 ? 就進入內部 var s = source.substring( 0 , index ) ; // 從 source 中擷取 index 之前的內容 ( index 以及 index 之後的內容都被捨棄 ) //console.log( "s : " + s ) ; var date = new Date(); // 建立一個 Date 物件的 一個 例項 var time = date.getTime() ; // 從 新建立的 Date 物件的例項中獲得該時間對應毫秒值 e.src = s + "?time=" + time ; // 將 加了 尾巴 的 地址 重新放入到 src 上 //console.log( e.src ) ; } else { var date = new Date(); e.src = source + "?time=" + date.getTime(); } } </script> </html>
2.User包的User類：
package com.cvs.bean; public class User { private String username; private String password; private int 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; } public int getId() { return id; } public void setId(int id) { this.id = id; } public User(String username, String password, int id) { super(); this.username = username; this.password = password; this.id = id; } public User() { super(); // TODO 自動生成的建構函式存根 } }
3.Dao包中兩個類：
1).BaseDao類
package com.cvs.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class BaseDao { protected Connection conn; protected PreparedStatement ps; public Connection getConnection() { String driver ="com.mysql.jdbc.Driver"; String url="jdbc:mysql://localhost:3306/soft6"; Connection conn=null; try { Class.forName(driver); conn =DriverManager.getConnection(url, "root", "root"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return conn; } public void closeAll(Connection conn ,Statement statement,ResultSet resultSet) { try { if (resultSet!=null) { resultSet.close(); } if (statement!=null) { statement.close(); } if (conn!=null) { conn.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
2).UserDao類
package com.cvs.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.cvs.bean.User;
public class UserDao extends BaseDao{
public User findUserbyuw(String username,String password) {
try {
User user=null;
//1.
//2.
Connection conn=getConnection();
//3.
PreparedStatement ps=conn.prepareStatement("select * from user where username=? and password=?");
ps.setString(1, username);//替換佔位符的？
ps.setString(2, password);
//4.
ResultSet res=ps.executeQuery();
while(res.next()) {
user=new User();
user.setId(res.getInt("id"));
user.setPassword(res.getString("password"));
user.setUsername(res.getString("username"));
}
while(res.next()) {
user=new User();
user.setId(res.getInt("id"));
user.setUsername(res.getString("username"));
}
//5.
closeAll(conn,ps,res);
return user;
}catch(SQLException e) {
e.printStackTrace();
}
return null;
}
public User findUserbyname(String username) {
try {
User user=null;
//1.
//2.
Connection conn=getConnection();
//3.
PreparedStatement ps=conn.prepareStatement("select * from user where username=?");
ps.setString(1, username);//替換佔位符的？
//4.
ResultSet res=ps.executeQuery();
while(res.next()) {
user=new User();
user.setUsername(res.getString("username"));
}
//5.
closeAll(conn,ps,res);
return user;
}catch(SQLException e) {
e.printStackTrace();
}
return null;
}
}
4.servlet包中的三個類：
1).ChackServlet類
package com.cvs.servlet;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
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.alibaba.fastjson.JSON;
import com.cvs.bean.User;
import com.cvs.dao.UserDao;
/**
* Servlet implementation class ChackServlet
*/
@WebServlet("/ChackServlet")
public class ChackServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public ChackServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.getWriter().append("Served at: ").append(request.getContextPath());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username=request.getParameter("username");
UserDao userDao=new UserDao();
User user=userDao.findUserbyname(username);
Map map=new HashMap();
if(user !=null) {
//判斷成功跑村使用者資訊到session
request.getSession().setAttribute("user", user);
map.put("msg", "已被註冊不可使用");
map.put("status", "ok");
} else {
map.put("msg","未被註冊可使用");
map.put("status", "error");
}
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("application/json;charset=UTF-8");
response.getWriter().print(JSON.toJSONString(map));
}
}
2).LoginServlet類
package com.cvs.servlet;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
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.alibaba.fastjson.JSON;
import com.cvs.bean.User;
import com.cvs.dao.UserDao;
/**
* Servlet implementation class LoginServlet
*/
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public LoginServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String code=(String) request.getSession().getAttribute("code");
String codes=request.getParameter("code");
String username=request.getParameter("username");
String password=request.getParameter("password");
//map設定返回的json資料
Map map=new HashMap();
if(!code.equals(codes)) {
map.put("msg", "驗證碼錯誤");
//輸出資訊到客戶端
response.setCharacterEncoding("utf-8");
response.setContentType("application/json;charset=UTF-8");
response.getWriter().print(JSON.toJSONString(map));
return;
}
UserDao userDao=new UserDao();
User user=userDao.findUserbyuw(username, password);
if(user != null) {
//判斷成功跑村使用者資訊到session
request.getSession().setAttribute("user", user);
map.put("msg","使用者登入成功");
map.put("status", "ok");
} else {
map.put("msg", "使用者名稱或者密碼錯誤");
map.put("status", "error");
}
//輸出資訊到客戶端
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("application/json;charset=UTF-8");
response.getWriter().print(JSON.toJSONString(map));
}
}
3).VerfyCodeServlet類
package com.cvs.servlet;
import java.io.IOException;
import java.io.OutputStream;
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 com.cvs.uitl.GraphicHelper;
@WebServlet(urlPatterns = "/VerfyCodeServlet" )
public class VerfyCodeServlet extends HttpServlet {
private static final long serialVersionUID = 3398560501558431737L;
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 獲得 當前請求 對應的 會話物件
HttpSession session = request.getSession();
// 從請求中獲得 URI ( 統一資源識別符號 )
String uri = request.getRequestURI();
System.out.println("hello : " + uri);
final int width = 180; // 圖片寬度
final int height = 40; // 圖片高度
final String imgType = "jpeg"; // 指定圖片格式 (不是指MIME型別)
final OutputStream output = response.getOutputStream(); // 獲得可以向客戶端返回圖片的輸出流
// (位元組流)
// 建立驗證碼圖片並返回圖片上的字串
String code = GraphicHelper.create(width, height, imgType, output);
System.out.println("驗證碼內容: " + code);
// 建立 uri 和 相應的 驗證碼 的關聯 ( 儲存到當前會話物件的屬性中 )
session.setAttribute("code", code);
// System.out.println(session.getAttribute(uri));
}
}
5.uitl包中的GraphicHelper類
package com.cvs.uitl;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
public final class GraphicHelper {
/**
* 以字串形式返回生成的驗證碼，同時輸出一個圖片
*
* @param width
* 圖片的寬度
* @param height
* 圖片的高度
* @param imgType
* 圖片的型別
* @param output
* 圖片的輸出流(圖片將輸出到這個流中)
* @return 返回所生成的驗證碼(字串)
*/
public static String create(final int width, final int height, final String imgType, OutputStream output) {
StringBuffer sb = new StringBuffer();
Random random = new Random();
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics graphic = image.getGraphics();
graphic.setColor(Color.getColor("F8F8F8"));
graphic.fillRect(0, 0, width, height);
Color[] colors = new Color[] { Color.BLUE, Color.GRAY, Color.GREEN, Color.RED, Color.BLACK, Color.ORANGE,
Color.CYAN };
// 在 "畫板"上生成干擾線條 ( 50 是線條個數)
for (int i = 0; i < 50; i++) {
graphic.setColor(colors[random.nextInt(colors.length)]);
final int x = random.nextInt(width);
final int y = random.nextInt(height);
final int w = random.nextInt(20);
final int h = random.nextInt(20);
final int signA = random.nextBoolean() ? 1 : -1;
final int signB = random.nextBoolean() ? 1 : -1;
graphic.drawLine(x, y, x + w * signA, y + h * signB);
}
// 在 "畫板"上繪製字母
graphic.setFont(new Font("Comic Sans MS", Font.BOLD, 30));
for (int i = 0; i < 6; i++) {
final int temp = random.nextInt(26) + 97;
String s = String.valueOf((char) temp);
sb.append(s);
graphic.setColor(colors[random.nextInt(colors.length)]);
graphic.drawString(s, i * (width / 6), height - (height / 3));
}
graphic.dispose();
try {
ImageIO.write(image, imgType, output);
} catch (IOException e) {
e.printStackTrace();
}
return sb.toString();
}
}
其中需要兩個jar包與資料庫，jar包分別為JSON的jar包和mysql的jar包，另外資料庫與登入成功頁面自行建立。
執行截圖如下：
