目录
一、什么是JWT：
二、Jwt的使用：
第一步：引入依赖：
第二步：配置拦截器：JwtInterceptor.java：
其中异常文件ServiceException配置如下：
全局异常文件GlobalException.java文件配置如下：
其中所需的Result配置如下：
第三步：配置拦截设置文件：InterceptorConfig.java：
第四步：配置Token工具类文件：TokenUtils.java：
request.js的axios封装文件为：
文件布局大致如下：
一、什么是JWT：
JWT是token的一种实现方式，全称是：JSON Wwb Token。简单来讲，Jwt是一种字符串，可以根据用户信息进行相关的编码操作生成带有用户信息的JWT token，我们可以根据这个来判断其信息是否正确或者是否被篡改。
二、Jwt的使用：
首先是后端：第一步：引入依赖：
<dependency><groupId>com.auth0</groupId><artifactId>java-jwt</artifactId><version>4.3.0</version></dependency>第二步：配置拦截器：JwtInterceptor.java：
import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTVerificationException;
import com.example.cqcrhouduan.Utils.TokenUtils;
import com.example.cqcrhouduan.exception.ServiceException;
import com.example.cqcrhouduan.mapper.UserMapper;
import io.micrometer.common.util.StringUtils;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;@Component
@Slf4j
public class JwtInterceptor implements HandlerInterceptor {@Autowiredprivate UserMapper userMapper;@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {if(request.getMethod().equals("OPTIONS")){return true;}String token = request.getHeader("token");if (StringUtils.isEmpty(token)) {token = request.getParameter("token");}token = token;// 执行认证if (StringUtils.isEmpty(token)) {throw new ServiceException(401, "无token，请重新登录");}// 获取 token 中的adminIdString userId;User user;try {userId = JWT.decode(token).getAudience().get(0); //解码// 根据token中的userid查询数据库user = userMapper.getById(Integer.parseInt(userId));user = user;} catch (Exception e) {String errMsg = "token验证失败，请重新登录";log.error(errMsg + ", token=" + token, e);throw new ServiceException(401, errMsg);}if (user == null) {throw new ServiceException(401, "用户不存在，请重新登录");}try {// 用户密码加签验证 tokenJWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(user.getPassword())).build();jwtVerifier.verify(token); // 验证token} catch (JWTVerificationException e) {throw new ServiceException(401, "token验证失败，请重新登录");}return true;}
}其中异常文件ServiceException配置如下：
import com.example.cqcrhouduan.pojo.Result;
import lombok.Data;@Data
public class ServiceException extends RuntimeException {private int code;public ServiceException(String msg){super(msg);this.code = 500;}public ServiceException(int code, String msg){super(msg);this.code = code;}
}
全局异常文件GlobalException.java文件配置如下：
import com.example.cqcrhouduan.pojo.Result;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;//自定义异常
@ControllerAdvice
public class GlobalException {@ExceptionHandler(ServiceException.class)@ResponseBodypublic Result serviceException(ServiceException e){return Result.error(e.getCode(),e.getMessage());}
}
其中所需的Result配置如下：
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@NoArgsConstructor
@AllArgsConstructor
public class Result {private Integer code;private String msg;private Object data;public static Result success(Object data){return new Result(200,"success",data);}public static Result success(){return new Result(200,"success",null);}public static Result error(String msg){return new Result(500,msg,null);}public static Result error(Integer Code ,String msg){return new Result(Code,msg,null);}}
第三步：配置拦截设置文件：InterceptorConfig.java：
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;@Configuration
public class InterceptorConfig extends WebMvcConfigurationSupport {// 加自定义拦截器JwtInterceptor，设置拦截规则@Overrideprotected void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(jwtInterceptor()).addPathPatterns("/**").excludePathPatterns("/login","/register");super.addInterceptors(registry);}@Beanpublic JwtInterceptor jwtInterceptor(){return new JwtInterceptor();}
}
第四步：配置Token工具类文件：TokenUtils.java：
import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.example.cqcrhouduan.mapper.UserMapper;
import com.example.cqcrhouduan.pojo.User;
import jakarta.annotation.PostConstruct;
import jakarta.annotation.Resource;
import jakarta.servlet.http.HttpServletRequest;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;@Component
@Slf4j
public class TokenUtils {private static UserMapper staticAdminService;@Resourceprivate UserMapper adminService;@PostConstructpublic void setUserService() {staticAdminService = adminService;}/*** 生成token** @return*/public static String genToken(int adminId, String sign) {return JWT.create().withAudience(Integer.toString(adminId)) // 将 user id 保存到 token 里面,作为载荷.withExpiresAt(DateUtil.offsetHours(new Date(), 2)) // 2小时后token过期.sign(Algorithm.HMAC256(sign)); // 以 password 作为 token 的密钥}/*** 获取当前登录的用户信息** @return user对象* /admin?token=xxxx*/public static User getCurrentAdmin() {String token = null;try {HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();token = request.getHeader("token");if (StringUtils.isNotBlank(token)) {token = request.getParameter("token");}if (StringUtils.isBlank(token)) {log.error("获取当前登录的token失败， token: {}", token);return null;}String userId = JWT.decode(token).getAudience().get(0);return staticAdminService.getById(Integer.valueOf(userId));} catch (Exception e) {log.error("获取当前登录的管理员信息失败, token={}", token, e);return null;}}
}然后是前端axios配置：
request.js的axios封装文件为：
import axios from "axios";
import router from "../modules/router.js";const request = axios.create({baseURL:'http://localhost:8080/', //自己的请求地址timeout:30000,
})// Add a request interceptor
request.interceptors.request.use((config) => {config.headers['Content-Type'] = 'application/json;charset=utf-8';let user = JSON.parse(localStorage.getItem("userToken") || '{}')// console.log(user.token) //查看tokenconfig.headers['token'] = user.token// config.headers.Authorization = localStorage.getItem("userToken")console.log("ok")// Do something before request is sentreturn config;
}, error => {console.log('request error' + error)// Do something with request errorreturn Promise.reject(error);
});// Add a response interceptor
request.interceptors.response.use(response => {let res = response.data;if (typeof res === 'string'){res = res ? JSON.parse(res) : res}// if(res.code === 401){ //自动跳转// router.push('/')// }// Any status code that lie within the range of 2xx cause this function to trigger// Do something with response datareturn res;
}, function (error) {// Any status codes that falls outside the range of 2xx cause this function to trigger// Do something with response errorconsole.log('response error' + error)return Promise.reject(error);
});export default request
文件布局大致如下：
