vue+springboot实现登录验证码（前后端分离）

前言

要实现验证码功能需要明白：
前端：通过img标签获得图片
后端：首先根据前端请求生成图片，然后前端再次处理前端的登录请求

一、流程

1.验证码生成工具类

此工具类用于生成验证码图片

package com.pp.educational_management_system.config;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

public class VerificationCode {
    private int width = 100;// 生成验证码图片的宽度
    private int height = 30;// 生成验证码图片的高度
    private String[] fontNames = { "宋体", "楷体", "隶书", "微软雅黑" };
    private Color bgColor = new Color(255, 255, 255);// 定义验证码图片的背景颜色为白色
    private Random random = new Random();
    private String codes = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    private String text;// 记录随机字符串

    /**
     * 获取一个随意颜色
     *
     * @return
     */
    private Color randomColor() {
        int red = random.nextInt(150);
        int green = random.nextInt(150);
        int blue = random.nextInt(150);
        return new Color(red, green, blue);
    }

    /**
     * 获取一个随机字体
     *
     * @return
     */
    private Font randomFont() {
        String name = fontNames[random.nextInt(fontNames.length)];
        int style = random.nextInt(4);
        int size = random.nextInt(5) + 24;
        return new Font(name, style, size);
    }

    /**
     * 获取一个随机字符
     *
     * @return
     */
    private char randomChar() {
        return codes.charAt(random.nextInt(codes.length()));
    }

    /**
     * 创建一个空白的BufferedImage对象
     *
     * @return
     */
    private BufferedImage createImage() {
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        g2.setColor(bgColor);// 设置验证码图片的背景颜色
        g2.fillRect(0, 0, width, height);
        return image;
    }

    public BufferedImage getImage() {
        BufferedImage image = createImage();
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < 4; i++) {
            String s = randomChar() + "";
            sb.append(s);
            g2.setColor(randomColor());
            g2.setFont(randomFont());
            float x = i * width * 1.0f / 4;
            g2.drawString(s, x, height - 8);
        }
        this.text = sb.toString();
        drawLine(image);
        return image;
    }

    /**
     * 绘制干扰线
     *
     * @param image
     */
    private void drawLine(BufferedImage image) {
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        int num = 5;
        for (int i = 0; i < num; i++) {
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            int x2 = random.nextInt(width);
            int y2 = random.nextInt(height);
            g2.setColor(randomColor());
            g2.setStroke(new BasicStroke(1.5f));
            g2.drawLine(x1, y1, x2, y2);
        }
    }

    public String getText() {
        return text;
    }

    public static void output(BufferedImage image, OutputStream out) throws IOException {
        ImageIO.write(image, "JPEG", out);
    }
}

2.图片请求

前端：

<img class="verifyCodeImg" :src="imgUrl" @click="resetImg">

imgUrl在数据区定义(new Date()生成随机事件用于更换验证码，防止浏览器缓存):

imgUrl:"http://localhost:9000/home/verifyCode?time="+new Date(),

resetImg方法用于点击更换验证码 图片

resetImg(){
        this.imgUrl = "http://localhost:9000/home/verifyCode?time="+new Date();
    },

后端:
生成验证码图片返回到前端，并且将验证码的code存在session中

	@GetMapping("/verifyCode")
    public void verifyCode(HttpServletRequest request, HttpServletResponse resp) throws IOException {
        VerificationCode code = new VerificationCode();
        BufferedImage image = code.getImage();
        String text = code.getText();
        HttpSession session = request.getSession(true);
        session.setAttribute("verify_code", text);
        VerificationCode.output(image,resp.getOutputStream());
    }

3.后端进行登录验证

（前后端分离项目此处有坑！！！！！！）
前端获取验证码的时候将code存在了session中，在登录验证的时候只需要将用户输入的验证码code和session中的code比较就行了。但是因为是前后端分离的项目，每次前端的ajax请求都是新的，每次请求的sessionID都不一样，所以每次使用的session不是同一个，以至于登录时session里面的值为null。
解决方式
在vue的main.js中配置axios，让每次请求都带上浏览器的cookie，这样后端使用的session就是同一个了。

	axios.defaults.withCredentials = true

源代码

前端：

	<template>
  <div class="login_container">
    <img :src="imgSrc" width="100%" height="100%" />
    <!--登录块-->
    <div class="login_box">
      <!--表单区域-->
      <el-form
        ref="loginFromRef"
        :rules="loginRules"
        :model="loginFrom"
        class="login_from"
        label-width="0px"
      >
        <h3 class="headline">教学管理系统</h3>
        <!--用户名-->
        <el-form-item prop="username">
          <el-input
            v-model="loginFrom.username"
            prefix-icon="iconfont icon-denglu"
            placeholder="用户名"
          ></el-input>
        </el-form-item>
        <!--密码-->
        <el-form-item prop="password">
          
          <el-input
            v-model="loginFrom.password"
            prefix-icon="iconfont icon-mima"
            type="password"
            placeholder="密码"
          ></el-input>
        </el-form-item>

        <el-form-item prop="verifyCode">
          <el-col :span="16">
            <el-input
            v-model="loginFrom.verifyCode"
            prefix-icon="el-icon-message"
            placeholder="验证码"
            class="verifyCode"
          ></el-input>
          </el-col>
          <el-col :span="8">
            <img class="verifyCodeImg" :src="imgUrl" @click="resetImg">
          </el-col>
          
          
        </el-form-item>

        <!--按钮-->
        <el-form-item class="btn">
          <el-button type="primary" @click="login">登录</el-button>
          <!-- <el-button type="info" @click="resetLoginForm">重置</el-button> -->
        </el-form-item>
      </el-form>
    </div>
  </div>
</template>
<script>
export default {
  data() {
    return {
      //表单数据
      imgUrl:"http://localhost:9000/home/verifyCode?time="+new Date(),
      loginFrom: {
        username: "admin",
        password: "123456",
        verifyCode:"",
      },
      //验证对象
      loginRules: {
        //校验用户名
        username: [
          { required: true, message: "请输入用户名称", trigger: "blur" }, //必填项验证
          {
            min: 5,
            max: 12,
            message: "长度在 5 到 12 个字符",
            trigger: "blur",
          }, //验证长度
        ],
        //校验密码
        password: [
          { required: true, message: "请输入用户密码", trigger: "blur" }, //必填项验证
          {
            min: 6,
            max: 10,
            message: "长度在 6 到 10 个字符",
            trigger: "blur",
          }, //验证长度
        ],
      },
      imgSrc: require("../assets/bg.png"),
    };
  },
  methods: {
    resetLoginForm() {
      //重置表单内容
      this.$refs.loginFromRef.resetFields();
    },
    resetImg(){
        this.imgUrl = "http://localhost:9000/home/verifyCode?time="+new Date();
    },
    login() {
      //登录请求
      this.$refs.loginFromRef.validate(async (validate) => {
        //判断是否验证成功
        if (!validate) return;
        const { data: res } = await this.$http.post(
          "home/login",
          this.loginFrom
        );
        
        

        if (res.status == "200") {
          this.$message.success("登陆成功");
          window.sessionStorage.setItem("user", res.id);
          const {data:res1} = await this.$http.get("menus",{params:{
          id:window.sessionStorage.getItem("user"),
          }});
          window.sessionStorage.setItem("menu",window.JSON.stringify(res1.menus));
          window.sessionStorage.setItem("token", res.token);
          //跳转页面
          this.$router.push({ path: "/home" });
        } else if(res.status == "400"){
          this.$message.error("用户名或密码错误");
        }else if(res.status == "404"){
          this.$message.error("账号未**，请联系管理员");
        }else{
          this.$message.error("验证码输入错误");
          this.imgUrl = "http://localhost:9000/home/verifyCode?time="+new Date();
        }

        
  
      });
    },
  },
};
</script>
<style lang="less" scoped>
.login_container {
  background-color: #2b4b6b;
  height: 100%;
}
.login_box {
  background: rgba(78, 102, 112, 0.1);
  width: 450px;
  height: 330px;
  border-radius: 5px;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}
.btn {
  width: 100%;
}
.login_from {
  position: absolute;
  bottom: 0%;
  width: 100%;
  padding: 0 10px;
  box-sizing: border-box;
  .verifyCode {
    width:"60%",
  }
  .verifyCodeImg {
    margin-top: 5px;
    margin-left: 10px;
    height: 30px;
    width:"60%",
  }
}
.el-button {
  margin-left: 10%;
  width: 80%;
}
.el-form-item {
  margin-left: 10%;
  width: 80%;
}
.headline {
  font-size: 20px;
  color: white;
  margin-left: 35%;
}
</style>

后端：

package com.pp.educational_management_system.controller;

import com.alibaba.fastjson.JSON;
import com.pp.educational_management_system.anotation.Log;
import com.pp.educational_management_system.config.VerificationCode;
import com.pp.educational_management_system.domain.User;
import com.pp.educational_management_system.service.impl.ShiroService;
import com.pp.educational_management_system.utils.MD5Utils;
import org.springframework.web.bind.annotation.*;

import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

@RestController
@RequestMapping("/home")
public class ShiroController {

    public static User user;

    private final ShiroService shiroService;

    public ShiroController(ShiroService shiroService) {
        this.shiroService = shiroService;
    }


    /**
     * 登录
     */
    @Log("登录")
    @RequestMapping("/login")
    public String login(@RequestBody User us, HttpServletRequest request, HttpServletResponse resp) {
        Map<String, Object> result = new HashMap<>();
        if(request.getSession(true).getAttribute("verify_code")==null||!us.getVerifyCode().toUpperCase().equals(request.getSession(true).getAttribute("verify_code").toString().toUpperCase())){
            result.put("status", 300);
            result.put("msg", "验证码错误");
            return JSON.toJSONString(result);
        }

        String username = us.getUsername();
        String password = us.getPassword();
        //用户信息
        User user = shiroService.getUserByName(username);

        //账号不存在、密码错误
        if (user == null || !user.getPassword().equals(MD5Utils.generatePassword(password))) {
            result.put("status", 400);
            result.put("msg", "账号或密码有误");
        }else if(user.getState()==0){
            result.put("status", 404);
            result.put("msg", "账号未**，请联系管理员");
        }else {
            this.user = user;
            //生成token，并保存到数据库
            result = shiroService.createToken(user.getId());
            result.put("status", 200);
            result.put("msg", "登陆成功");
            result.put("id",user.getId());
        }
        String res = JSON.toJSONString(result);
        return res;
    }

    /**
     * 得到验证码图片
     * @param request
     * @param resp
     * @throws IOException
     */
    @GetMapping("/verifyCode")
    public void verifyCode(HttpServletRequest request, HttpServletResponse resp) throws IOException {
        VerificationCode code = new VerificationCode();
        BufferedImage image = code.getImage();
        String text = code.getText();
        HttpSession session = request.getSession(true);
        session.setAttribute("verify_code", text);
        VerificationCode.output(image,resp.getOutputStream());
    }

    /**
     * 退出
     */
    @RequestMapping("/logout")
    public Map<String, Object> logout(@RequestHeader("token")String token) {
        Map<String, Object> result = new HashMap<>();
        shiroService.logout(token);
        result.put("status", 200);
        result.put("msg", "您已安全退出系统");
        return result;
    }

}