springboot JWT密钥 调用filter或Interceptor拦截

LoginController

package com.itheima.controller;
import com.itheima.pojo.Emp;
import com.itheima.pojo.Result;
import com.itheima.service.EService;
import com.itheima.utils.JwtUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import java.util.HashMap;
import java.util.Map;
@Slf4j
@RestController
public class LoginController {
    @Autowired
    private EService eService;
    @PostMapping("/login")
    public Result login(@RequestBody Emp emp){
        log.info("员工登录: {}", emp);
//调用Service层和Mapper层查看是否存在该员工
        Emp e = eService.Login(emp);
        //登录成功,生成令牌,下发令牌
        if (e != null){
            Map claims = new HashMap();
            claims.put("id", e.getId());
            claims.put("name", e.getName());
            claims.put("username", e.getUsername());
            String jwt = JwtUtils.generateJwt(claims); //jwt包含了当前登录的员工信息
            return Result.success(jwt);
        }
        //登录失败, 返回错误信息
        return Result.error("失败");
    }
}

导入JWT工具类

package com.itheima.utils;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import java.util.Date;
import java.util.Map;
public class JwtUtils {
    private static String signKey = "itheima";
    private static Long expire = 43200000L;
    /**
     * 生成JWT令牌
     * @param claims JWT第二部分负载 payload 中存储的内容
     * @return
     */
    public static String generateJwt(Map claims){
        String jwt = Jwts.builder()
                .addClaims(claims)
                .signWith(SignatureAlgorithm.HS256, signKey)
                .setExpiration(new Date(System.currentTimeMillis() + expire))
                .compact();
        return jwt;
    }
    /**
     * 解析JWT令牌
     * @param jwt JWT令牌
     * @return JWT第二部分负载 payload 中存储的内容
     */
    public static Claims parseJWT(String jwt){
        Claims claims = Jwts.parser()
                .setSigningKey(signKey)
                .parseClaimsJws(jwt)
                .getBody();
        return claims;
    }
}

使用Interceptor拦截

package com.itheima.interceptor;
import com.alibaba.fastjson.JSONObject;
import com.itheima.pojo.Result;
import com.itheima.utils.JwtUtils;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.HeaderIterator;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@Slf4j
@Component
public class LoginCheckInterceptor implements HandlerInterceptor {
    @Override//目标方法运行前运行，true: 放行  false:不放行
    public boolean preHandle(HttpServletRequest req, HttpServletResponse res, Object handler) throws Exception {
        System.out.println("preHandle");
        String url = req.getRequestURL().toString();
        //判定url中是否包含login
        if (url.contains("login")){
            log.info("登录操作，，，放行");
            return true;
        }
        //获取请求头的令牌（token）
        String token = req.getHeader("token");
        //检测令牌是否存在
        if(!StringUtils.hasLength(token)){
            log.info("令牌不存在");
            Result error = Result.error("NOT_LOGIN");
            String notLogin = JSONObject.toJSONString(error);
            res.getWriter().write(notLogin);
            return false;
        }
        //解析令牌
        try {
            JwtUtils.parseJWT(token);
        } catch (Exception e) {
            log.info("令牌解析失败");
            Result error = Result.error("NOT_LOGIN");
            String notLogin = JSONObject.toJSONString(error);
            res.getWriter().write(notLogin);
            return false;
        }
        log.info("解析成功");
        return true;
    }
    @Override//目标资源方法后运行
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle");
     }
    @Override//最后运行
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion");
        }
}

该拦截器的配置类

package com.itheima.config;
import com.itheima.interceptor.LoginCheckInterceptor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration //配置类
public class WebConfig implements WebMvcConfigurer {
    @Autowired
    private LoginCheckInterceptor loginCheckInterceptor;
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(loginCheckInterceptor).addPathPatterns("/**").excludePathPatterns("/login");
    }
}

使用Filter过滤

package com.itheima.filter;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.support.spring.annotation.FastJsonFilter;
import com.itheima.pojo.Result;
import com.itheima.utils.JwtUtils;
import io.jsonwebtoken.Claims;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.http.HttpResponse;
@Slf4j
//@WebFilter("/*")
public class LoginCheckFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        //获取url
        HttpServletRequest req=(HttpServletRequest) request;
        HttpServletResponse res=(HttpServletResponse) response;
        String url = req.getRequestURL().toString();
        //判定url中是否包含login
        if (url.contains("login")){
            log.info("登录操作，，，放行");
            chain.doFilter(request,response);
            return;
        }
        //获取请求头的令牌（token）
        String token = req.getHeader("token");
        //检测令牌是否存在
        if(!StringUtils.hasLength(token)){
            log.info("令牌不存在");
            Result error = Result.error("NOT_LOGIN");
            String notLogin = JSONObject.toJSONString(error);
            res.getWriter().write(notLogin);
            return;
        }
        //解析令牌
        try {
            JwtUtils.parseJWT(token);
        } catch (Exception e) {
            log.info("令牌解析失败");
        }
        log.info("解析成功");
        chain.doFilter(request,response);
    }
}