SpringBoot integrates JWT token to implement permission verification

First introduce JWT dependency in pom

<!-- JWT -->
<dependency>
  <groupId>com.auth0</groupId>
  <artifactId>java-jwt</artifactId>
  <version>4.3.0</version>
</dependency>

Then introduce a generated token tool class

import cn.hutool.core.date.DateUtil;
import cn.hutool.core.util.StrUtil;
import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.example.boot.entity.User;
import com.example.boot.mapper.UserMapper;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import java.util.Date;

@Component
public class TokenUtils {

    private static UserMapper staticUserMapper;

    @Resource
    UserMapper userMapper;

    @PostConstruct
    public void setUserService() {
        staticUserMapper = userMapper;
    }

    /**
     * 生成token
     *
     * @return
     */
    public static String genToken(String userId, String sign) {
        return JWT.create().withAudience(userId) // 将 user id 保存到 token 里面,作为载荷
                .withExpiresAt(DateUtil.offsetHour(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
     */
    public static User getCurrentUser() {
        try {
            HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
            String token = request.getHeader("token");
            if (StrUtil.isNotBlank(token)) {
                String userId = JWT.decode(token).getAudience().get(0);
                return staticUserMapper.selectById(Integer.valueOf(userId));
            }
        } catch (Exception e) {
            return null;
        }
        return null;
    }
}

        Then there are two ways to implement it, one is to use custom annotations with interceptors, and the other is to use interceptors.

method one:

        First customize an annotation, then define a custom interceptor JwtInterceptor class, and let the JwtInterceptor class inherit the HandlerInterceptor class.

import java.lang.annotation.*;

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface AuthAccess {

}

 Method Two:

        Directly write a custom interceptor JwtInterceptor 

import cn.hutool.core.util.StrUtil;
import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import com.example.boot.common.Result;
import com.example.boot.entity.User;
import com.example.boot.exception.ServiceException;
import com.example.boot.mapper.UserMapper;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class JwtInterceptor implements HandlerInterceptor {

    @Resource
    private UserMapper userMapper;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
        String token = request.getHeader("token");
        if (StrUtil.isBlank(token)) {
            token = request.getParameter("token");
        }
        // 如果不是映射到方法直接通过
        if (handler instanceof HandlerMethod) {
            AuthAccess annotation = ((HandlerMethod) handler).getMethodAnnotation(AuthAccess.class);
            if (annotation != null) {
                return true;
            }
        }
        // 执行认证
        if (StrUtil.isBlank(token)) {
            throw new ServiceException("401", "请登录");
        }
        // 获取 token 中的 user id
        String userId;
        try {
            userId = JWT.decode(token).getAudience().get(0);
        } catch (JWTDecodeException j) {
            throw new ServiceException("401", "请登录");
        }
        // 根据token中的userid查询数据库
        User user = userMapper.selectById(userId);
        if (user == null) {
            throw new ServiceException("401", "请登录");
        }
        // 用户密码加签验证 token
        JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(user.getPassword())).build();
        try {
            jwtVerifier.verify(token); // 验证token
        } catch (JWTVerificationException e) {
            throw new ServiceException("401", "请登录");
        }
        return true;
    }
}

        Write another configuration interceptor InterceptorConfig class

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.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;

@Configuration
public class InterceptorConfig extends WebMvcConfigurationSupport {

    @Override
    protected void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(jwtInterceptor())
                .addPathPatterns("/**")
        super.addInterceptors(registry);
    }

    @Bean
    public JwtInterceptor jwtInterceptor() {
        return new JwtInterceptor();
    }

}

 Of course, the front end is in the request.js file

let user = JSON.parse(localStorage.getItem("honey-user") || '{}')
config.headers['token'] = user.token  // 设置请求头