Java实现的登录功能（三层架构，验证，拦截）

Java实现的登录功能（三层架构，验证，拦截）

1、pojo：实体类

package com.pojo;

public class User {
    private int id;
    private String name;
    private String password;

    public User() {
    }

    public User(String name, String password) {
        this.name = name;
        this.password = password;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

2、dao
接口：

package com.dao;

import com.pojo.User;

public interface UserDao {
    boolean user(User user);
}

实现类：

package com.dao.impl;

import com.dao.UserDao;
import com.pojo.User;
import com.util.JdbcUtil;
import org.springframework.jdbc.core.JdbcTemplate;

import java.util.List;
import java.util.Map;

public class UserDaoImpl implements UserDao {
    @Override
    //查询用户是否存在
    public boolean user(User user) {
        JdbcTemplate jdbc = new JdbcTemplate(JdbcUtil.getDs());
        try {
            List<Map<String, Object>> maps = jdbc.queryForList("select * from user where name=? and password=?", user.getName(), user.getPassword());
            return maps.size() != 0;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }
}

3、service
接口：

package com.service;

import com.pojo.User;

public interface UserService {
    boolean user(User user);
}

实现类：

package com.service.impl;

import com.dao.UserDao;
import com.dao.impl.UserDaoImpl;
import com.pojo.User;
import com.service.UserService;

public class UserServiceImpl implements UserService {
  private   UserDao userDao=new UserDaoImpl();
    @Override
    public boolean user(User user) {
        return userDao.user(user);
    }
}

4、web

package com.web;

import com.pojo.User;
import com.service.UserService;
import com.service.impl.UserServiceImpl;
import com.util.GenerateCode;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/user")
public class UserServlet extends HttpServlet {
    private UserService userService=new UserServiceImpl();
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        String name = request.getParameter("name");
        String psw = request.getParameter("password");
        String code = request.getParameter("code");
        String muan = request.getParameter("muan");
        User user1=new User(name,psw);
        boolean br = userService.user(user1);
        //用户名和密码判断
        if (!br) {
            request.setAttribute("msg", "用户名或密码错误");
            request.getRequestDispatcher("/login.jsp").forward(request, response);
            return;
        }
        //验证码判断

        if (!code.equalsIgnoreCase((String) request.getSession().getAttribute("cod1"))) {
            request.setAttribute("msg", "验证码错误");
            request.getRequestDispatcher("/login.jsp").forward(request, response);
            return;
        }
        request.getSession().setAttribute("name",name);
        //登录成功后7天免登录
        if (muan!=null&&muan.equals("yes")) {
            System.out.println("ok");
            request.getSession().setMaxInactiveInterval(60*24*7);
            Cookie cookie=new Cookie("JSESSIONID",(String) request.getSession().getId());
            cookie.setMaxAge(60*60*24*7);
            response.addCookie(cookie);
        }else {
            request.getSession().setMaxInactiveInterval(-1);
            Cookie cookie=new Cookie("JSESSIONID",(String) request.getSession().getId());
            cookie.setMaxAge(1800);
            response.addCookie(cookie);
        }
        request.getRequestDispatcher("/success.jsp").forward(request, response);

    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    //将验证码传给界面
        String s = GenerateCode.outputVerifyImage(80, 30, response.getOutputStream(), 4);
        request.getSession().setAttribute("cod1", s);
    }
}

5、util:工具类
生成验证码的工具类

package com.util;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;

public class GenerateCode {

    //使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符
    public static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
    private static Random random = new Random();

    /**
     * 使用系统默认字符源生成验证码
     *
     * @param verifySize 验证码长度
     * @return
     */
    public static String generateVerifyCode(int verifySize) {
        return generateVerifyCode(verifySize, VERIFY_CODES);
    }

    /**
     * 使用指定源生成验证码
     *
     * @param verifySize 验证码长度
     * @param sources    验证码字符源
     * @return
     */
    public static String generateVerifyCode(int verifySize, String sources) {
        if (sources == null || sources.length() == 0) {
            sources = VERIFY_CODES;
        }
        int codesLen = sources.length();
        Random rand = new Random(System.currentTimeMillis());
        StringBuilder verifyCode = new StringBuilder(verifySize);
        for (int i = 0; i < verifySize; i++) {
            verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));
        }
        return verifyCode.toString();
    }

    /**
     * 生成随机验证码文件,并返回验证码值
     *
     * @param w
     * @param h
     * @param outputFile
     * @param verifySize
     * @return
     * @throws IOException
     */
    public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException {
        String verifyCode = generateVerifyCode(verifySize);
        outputImage(w, h, outputFile, verifyCode);
        return verifyCode;
    }

    /**
     * 输出随机验证码图片流,并返回验证码值
     *
     * @param w
     * @param h
     * @param os
     * @param verifySize
     * @return
     * @throws IOException
     */
    public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException {
        String verifyCode = generateVerifyCode(verifySize);
        outputImage(w, h, os, verifyCode);
        return verifyCode;
    }

    /**
     * 生成指定验证码图像文件
     *
     * @param w
     * @param h
     * @param outputFile
     * @param code
     * @throws IOException
     */
    public static void outputImage(int w, int h, File outputFile, String code) throws IOException {
        if (outputFile == null) {
            return;
        }
        File dir = outputFile.getParentFile();
        if (!dir.exists()) {
            dir.mkdirs();
        }
        try {
            outputFile.createNewFile();
            FileOutputStream fos = new FileOutputStream(outputFile);
            outputImage(w, h, fos, code);
            fos.close();
        } catch (IOException e) {
            throw e;
        }
    }

    /**
     * 输出指定验证码图片流
     *
     * @param w
     * @param h
     * @param os
     * @param code
     * @throws IOException
     */
    public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {
        int verifySize = code.length();
        BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        Random rand = new Random();
        Graphics2D g2 = image.createGraphics();
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        Color[] colors = new Color[5];
        Color[] colorSpaces = new Color[]{Color.WHITE, Color.CYAN,
                Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
                Color.PINK, Color.YELLOW};
        float[] fractions = new float[colors.length];
        for (int i = 0; i < colors.length; i++) {
            colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
            fractions[i] = rand.nextFloat();
        }
        Arrays.sort(fractions);

        g2.setColor(Color.GRAY);// 设置边框色
        g2.fillRect(0, 0, w, h);

        Color c = getRandColor(200, 250);
        g2.setColor(c);// 设置背景色
        g2.fillRect(0, 2, w, h - 4);

        //绘制干扰线
        Random random = new Random();
        g2.setColor(getRandColor(160, 200));// 设置线条的颜色
        for (int i = 0; i < 20; i++) {
            int x = random.nextInt(w - 1);
            int y = random.nextInt(h - 1);
            int xl = random.nextInt(6) + 1;
            int yl = random.nextInt(12) + 1;
            g2.drawLine(x, y, x + xl + 40, y + yl + 20);
        }

        // 添加噪点
        float yawpRate = 0.05f;// 噪声率
        int area = (int) (yawpRate * w * h);
        for (int i = 0; i < area; i++) {
            int x = random.nextInt(w);
            int y = random.nextInt(h);
            int rgb = getRandomIntColor();
            image.setRGB(x, y, rgb);
        }

        shear(g2, w, h, c);// 使图片扭曲

        g2.setColor(getRandColor(100, 160));
        int fontSize = h - 4;
        Font font = new Font("Algerian", Font.ITALIC, fontSize);
        g2.setFont(font);
        char[] chars = code.toCharArray();
        for (int i = 0; i < verifySize; i++) {
            AffineTransform affine = new AffineTransform();
            affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize / 2, h / 2);
            g2.setTransform(affine);
            g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);
        }

        g2.dispose();
        ImageIO.write(image, "png", os);
    }

    private static Color getRandColor(int fc, int bc) {
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

    private static int getRandomIntColor() {
        int[] rgb = getRandomRgb();
        int color = 0;
        for (int c : rgb) {
            color = color << 8;
            color = color | c;
        }
        return color;
    }

    private static int[] getRandomRgb() {
        int[] rgb = new int[3];
        for (int i = 0; i < 3; i++) {
            rgb[i] = random.nextInt(255);
        }
        return rgb;
    }

    private static void shear(Graphics g, int w1, int h1, Color color) {
        shearX(g, w1, h1, color);
        shearY(g, w1, h1, color);
    }

    private static void shearX(Graphics g, int w1, int h1, Color color) {

        int period = random.nextInt(2);

        boolean borderGap = true;
        int frames = 1;
        int phase = random.nextInt(2);

        for (int i = 0; i < h1; i++) {
            double d = (double) (period >> 1)
                    * Math.sin((double) i / (double) period
                    + (6.2831853071795862D * (double) phase)
                    / (double) frames);
            g.copyArea(0, i, w1, 1, (int) d, 0);
            if (borderGap) {
                g.setColor(color);
                g.drawLine((int) d, i, 0, i);
                g.drawLine((int) d + w1, i, w1, i);
            }
        }

    }

    private static void shearY(Graphics g, int w1, int h1, Color color) {

        int period = random.nextInt(40) + 10; // 50;

        boolean borderGap = true;
        int frames = 20;
        int phase = 7;
        for (int i = 0; i < w1; i++) {
            double d = (double) (period >> 1)
                    * Math.sin((double) i / (double) period
                    + (6.2831853071795862D * (double) phase)
                    / (double) frames);
            g.copyArea(i, 0, 1, h1, 0, (int) d);
            if (borderGap) {
                g.setColor(color);
                g.drawLine(i, (int) d, i, 0);
                g.drawLine(i, (int) d + h1, i, h1);
            }

        }
    }

}

提供连接池对象

package com.util;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.FileReader;
import java.util.Properties;

public class JdbcUtil {

    private static DataSource dos;



    static {
        Properties por=new Properties();
        try {
            por.load(new FileReader("D:\\IMJavaWeb\\day18\\src\\druid.properties"));
            dos = DruidDataSourceFactory.createDataSource(por);
        } catch (Exception e) {
            e.printStackTrace();
        }


    }


public static DataSource getDs(){
        return dos;
}



}

6、login.jsp
登录首页：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<%--提示信息--%>
<h3><%=request.getAttribute("msg")==null?"":request.getAttribute("msg")%></h3>
<hr>
<form action="/day18/user" method="post">
    <table>
        <tr>
            <td>用户名：</td>
            <td> <input name="name" type="text"></td>
        </tr>
        <tr>
            <td>密码：</td>
            <td> <input name="password" type="password"></td>
        </tr>
        <tr>
            <td>验证码：</td>
            <td> <input name="code" type="text"><img src="/day18/user" onclick="f()"></td>
        </tr>
        <tr>
            <td>7天免登录</td>
            <td> <input name="muan" type="checkbox" value="yes"></td>
        </tr>
        <tr>
            <td></td>
            <td> <input  type="submit" value="登录"></td>
        </tr>
    </table>
</form>
</body>
<script>
 /* 点击图片刷新验证码的方法，不会刷新页面*/
    function f(){
       date= new Date().getTime()
        document.getElementsByTagName("img").item(0).src="/day18/user?"+date
    }
</script>
</html>

7、success.jsp
登录成功页面：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<%--对普通访客进行拦截--%>
<%if (request.getSession().getAttribute("name")==null){
    response.sendRedirect("/day18/login.jsp");
}%>
<h1><%=request.getSession().getAttribute("name")%>，欢迎登录</h1>

</body>
</html>