前后端分离 基于session的验证码功能实现

前后端分离 基于session的验证码功能实现

1、后端代码

1.1 SessionContextUtils 用于获取session

import javax.servlet.http.HttpSession;
import java.util.HashMap;

/**
 * SessionContext用于获取session
 * 根据sessionId获取session
 */
public class SessionContextUtils {
    private static SessionContextUtils instance;
    private HashMap<String, HttpSession> sessionMap;

    private SessionContextUtils() {
        sessionMap = new HashMap<String,HttpSession>();
    }

    public static SessionContextUtils getInstance() {
        if (instance == null) {
            instance = new SessionContextUtils();
        }
        return instance;
    }

    public synchronized void addSession(HttpSession session) {
        if (session != null) {
            sessionMap.put(session.getId(), session);
        }
    }

    public synchronized void delSession(HttpSession session) {
        if (session != null) {
            sessionMap.remove(session.getId());
        }
    }

    public synchronized HttpSession getSession(String sessionID) {
        if (sessionID == null) {
            return null;
        }
        return sessionMap.get(sessionID);
    }
}

1.2 SessionListener 用于监听session

import com.utils.SessionContextUtils;

import javax.servlet.annotation.WebListener;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

/**
 * 监听session
 */
@WebListener
public class SessionListener implements HttpSessionListener {

    private SessionContextUtils sessionContext= SessionContextUtils.getInstance();

    @Override
    public void sessionCreated(HttpSessionEvent httpSessionEvent) {
        HttpSession session = httpSessionEvent.getSession();
        sessionContext.addSession(session);
    }

    @Override
    public void sessionDestroyed(HttpSessionEvent httpSessionEvent) {
        HttpSession session = httpSessionEvent.getSession();
        sessionContext.delSession(session);
    }
}

1.3 在启动类加上@ServletComponentScan注解

/**
 * 启动类
 *
 */
@ServletComponentScan
@SpringBootApplication
public class WebSiteApplication {
    public static void main(String[] args) {
        SpringApplication.run(WebSiteApplication.class, args);
        System.out.println("网站接口服务已启动成功……");
    }
}

1.4 验证码生成工具类

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
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;

import javax.imageio.ImageIO;

/**
 * @author liuhongxin
 * @Desc 验证码生成工具类
 * @date 2022年08月10日
 * @Version V1.0
 */
public class VerifyCodeUtils{

    //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, "jpg", 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);
            }

        }

    }
    public static void main(String[] args) throws IOException{
        File dir = new File("D:/upload/verifyCode");
        int w = 200, h = 80;
        for(int i = 0; i < 50; i++){
            String verifyCode = generateVerifyCode(4);
            File file = new File(dir, verifyCode + ".jpg");
            outputImage(w, h, file, verifyCode);
        }
    }
}

1.5 controller代码

import cn.hutool.core.codec.Base64;
import com.sic.common.resources.messages.R;
import com.sic.website.utils.SessionContextUtils;
import com.sic.website.utils.VerifyCodeUtils;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.ByteArrayOutputStream;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * @author liuhongxin
 * @@version 1.0
 * @date 20200809
 */
@RestController
@RequestMapping("/validateCode")
public class ValidateCodeAction {

    @GetMapping(value = "/get/code")
    public R getCode(HttpServletRequest request, HttpServletResponse response) {
        try {
            response.setHeader("Pragma", "No-cache");
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expires", 0);
            response.setContentType("image/jpeg");

            // 生成随机字串（VerifyCodeUtils验证码生成工具类就不贴出来了，网上随便一找好多的）
            String verifyCode = VerifyCodeUtils.generateVerifyCode(4);
            // 存入会话session
            HttpSession session = request.getSession(true);
            // 删除以前的
            session.removeAttribute("verCode");
            session.removeAttribute("codeTime");
            session.setAttribute("verCode", verifyCode.toLowerCase());
            session.setAttribute("codeTime", LocalDateTime.now());
            // 生成图片
            int w = 200, h = 50;
            ByteArrayOutputStream stream = new ByteArrayOutputStream();
            //注意，这里是将生成的图片转为base64的格式将返回给前端，而不是直接给张图片的地址。
            //这样获取验证码就是一个请求，而不是一张图片的地址，因为是一个请求，所以我们可以返回sessionid给前端。
            VerifyCodeUtils.outputImage(w, h, stream, verifyCode);
            try{
                String encode = Base64.encode(stream.toByteArray());
                Map<String,Object> map = new HashMap<>();
                map.put("img","data:image/png;base64,"+ encode);
                //返回sessionid给前端，前端只需要在调用登录接口的时候将这个sessionid设置到请求头中即可
                map.put("sessionId",session.getId());
                return R.ok(map);
            }catch (Exception e){

            }finally{
                stream.close();
            }
        } catch (Exception e) {
            System.out.println("验证码获取错误");
        }
        return R.error();
    }

    @PostMapping(value = "/checkCode")
    public R checkCode(@RequestParam String code, HttpServletRequest request) {

        Map<String, Object> data = new HashMap<>();
        //获取请求头中的sessionId，然后根据sessionId来获取session
        String sessionId = request.getHeader("sessionId");
        SessionContextUtils sessionContext= SessionContextUtils.getInstance();
        HttpSession session = sessionContext.getSession(sessionId);
        // 验证码
        Object verCode = session.getAttribute("verCode");
        if (null == verCode) {
//            data.put("msg", "验证码已失效，请重新输入");
//            data.put("type", 3);
//            return R.ok(data);
            return R.error(3, "验证码已失效，请重新输入");
        }

        String verCodeStr = verCode.toString();
        LocalDateTime localDateTime = (LocalDateTime) session.getAttribute("codeTime");
        ZoneId zoneId = ZoneId.systemDefault();
        ZonedDateTime zdt = localDateTime.atZone(zoneId);
        Date codeDateTime = Date.from(zdt.toInstant());

        if (verCodeStr == null || StringUtils.isEmpty(code) || !verCodeStr.equalsIgnoreCase(code)) {
//            data.put("msg", "验证码错误");
//            data.put("type", 3);
//            return R.ok(data);
            return R.error(3, "验证码错误");
        } else if (((System.currentTimeMillis()) - (codeDateTime.getTime())) > (1 * 60 * 1000)) {
//            data.put("msg", "验证码已过期,请重新输入");
//            data.put("type", 3);
//            return R.ok(data);
            return R.error(3, "验证码已过期,请重新输入");
        } else {
            //验证成功，删除存储的验证码
            session.removeAttribute("verCode");
            session.removeAttribute("codeTime");
        }
        //省略其他代码
        return R.ok();
    }

}

2 前端请求代码

此处仅贴出请求代码，具体展示逻辑根据项目不同自行编写。

let sessionId = '';
//获取sessionId 及 验证码图片
function getCode() {
    $.ajax({
        url: serverUrl + "/validateCode/get/code",
        async: false,
        type: 'get',
        data: {},
        success: function (data) {
            if (data.code == "1") {
                $("#zzc").hide();
            } else {
                sessionId = data.sessionId;
                var el = document.getElementById("zzcImg");
                el.src = data.img;
            }
        },
        error: function (data) {
            alert("系统异常");
        }
    });
}

function checkCode() {
    $.ajax({
        url: serverUrl + "/validateCode/checkCode",
        async: false,
        type: 'post',
        data: {
            "code": $("#zzcInput").val()
        },
        beforeSend: function (XMLHttpRequest) {
            XMLHttpRequest.setRequestHeader("sessionId", sessionId);
            },
        success: function (data) {
            if (data.code == "0") {
                $("#zzc").hide();
            } else {
                alert(data.msg);
            }
        },
        error: function (data) {
            alert("系统异常");
        }
    });
}