gateway + jwt 网关认证

思路： 全局过滤器对所有的请求拦截（生成token有效期30分钟，放入redis设置有效期3天。3天之类可以通过刷新接口自动刷新，超过3天需要重新登录。）

前端在调用接口之前先判断token是否过期（3o分钟），过期则先调刷新接口，换取新token,

1- 引入相关jar

<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>
<dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.0</version>
</dependency>

2- 编写Jwt工具类（生成token + 解析token）

package spring.cloud.gateway.common;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import io.jsonwebtoken.ExpiredJwtException;
import org.springframework.util.StringUtils;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;

public class JwtUtil {
    public static final String SECRET = "qazwsx123444$#%#()*&& asdaswwi1235 ?;!@#kmmmpom in***xx**&";
    public static final String TOKEN_PREFIX = "Bearer";
    public static final String LOGIN_URL = "/token/userId/pwd";
    public static final String LOGOUT_URL = "/token/userId";
    public static final String HEADER_AUTH = "authorization";
    public static final String HEADER_USERID = "userid";
    //token超时时间
    public static final int TOKEN_EXPIRATION_MINUTE = 30;
    //token的redis超时时间
    public static final int TOKEN_REDIS_EXPIRATION_DAY = 7;

    
    public static String generateToken(String userId) {
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MINUTE, TOKEN_EXPIRATION_MINUTE); //得到前一天
        Date date = calendar.getTime();
        DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        df.format(date);
        //todo 优化token的生层规则
        HashMap<String, Object> map = new HashMap<>();
        map.put(HEADER_USERID, userId);
        String jwt = Jwts.builder()
                .setSubject(HEADER_USERID).setClaims(map)
                .setExpiration(date)
                .signWith(SignatureAlgorithm.HS512, SECRET)
                .compact();
        return TOKEN_PREFIX + " " + jwt;
    }

    public static Map<String, String> validateToken(String token) {
        HashMap<String, String> tokenMap = new HashMap<String, String>();
        if (StringUtils.isEmpty(token)) {
            return tokenMap;
        }
        try {
            Map<String, Object> tokenBody = Jwts.parser()
                    .setSigningKey(SECRET)
                    .parseClaimsJws(token.replace(TOKEN_PREFIX, ""))
                    .getBody();
            String userId = String.valueOf(tokenBody.get(HEADER_USERID));
            tokenMap.put(HEADER_USERID, userId);
        }catch (ExpiredJwtException e){
            e.printStackTrace();
        }
        return tokenMap;
    }

    /**
     * 移到jwtUtil中去
     *
     * @param token
     * @return
     */
    public static Map<String, String> validateTokenAndUser(String token, String userIdIn) {
        Map<String, String> tokenResultMap = new HashMap<>();
        if (StringUtils.isEmpty(token) || StringUtils.isEmpty(userIdIn)) {
            return tokenResultMap;
        }
        tokenResultMap = validateToken(token);
        if (StringUtils.isEmpty(token) || StringUtils.isEmpty(userIdIn)) {
            return tokenResultMap;
        }
        //判断传入的userid和token是否匹配
        String userIdOri = tokenResultMap.get(HEADER_USERID);
        if (!userIdIn.equals(userIdOri)) {
            return new HashMap<String,String>();
        }
        return tokenResultMap;
    }

}

3- 编写过滤器类

package spring.cloud.gateway.filter;

import java.net.URI;
import java.util.Map;
import org.apache.commons.lang.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.cloud.gateway.route.Route;
import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.server.PathContainer;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
import spring.cloud.gateway.common.JwtUtil;
import spring.cloud.gateway.exception.PermissionException;

/**
 * 参数参考 https://blog.csdn.net/tianyaleixiaowu/article/details/83375246
 * response参考 https://bbs.csdn.net/topics/392412604?list=11074255
 */
@Component
public class AuthFilter implements GlobalFilter {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        HttpHeaders header = request.getHeaders();
        HttpMethod method = request.getMethod();
        String token = header.getFirst(JwtUtil.HEADER_AUTH);
        String userId = header.getFirst(JwtUtil.HEADER_USERID);
        PathContainer pathContainer = request.getPath().pathWithinApplication();
        String path = pathContainer.value();

        //2- 处理登录请求
        if (StringUtils.isBlank(token)) {
            //是登录接口则放行，否则返回异常
            if (path.contains(JwtUtil.LOGIN_URL) && HttpMethod.POST.equals(method)) {
                throw new PermissionException("please login");
            }
            return chain.filter(exchange);
        }

        //3- 处理刷新token请求
        if (path.indexOf("refresh") >= 0) {
            //放行去掉刷新接口（在刷新前校验userId和token是否匹配）
            return chain.filter(exchange);
        }

        //4- 处理刷新token请求
        if (path.contains(JwtUtil.LOGOUT_URL) && HttpMethod.DELETE.equals(method)) {
            //放行去掉登出接口（在刷新前校验userId和token是否匹配）
            return chain.filter(exchange);
        }

        //5- 携带token请求其他业务接口
        Map<String, String> validateResultMap = JwtUtil.validateTokenAndUser(token, userId);
        if (validateResultMap == null || validateResultMap.isEmpty()) {
            throw new PermissionException("token 已经失效");
        }
        // TODO 将用户信息存放在请求header中传递给下游业务
        Route gatewayUrl = exchange.getRequiredAttribute(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR);
        URI uri = gatewayUrl.getUri();
        //表示下游请求对应的服务名如 SPRING-CLOUD-SERVICE  SPRING-CLOUD-GATEWAY
        String serviceName = uri.getHost();

        ServerHttpRequest.Builder mutate = request.mutate();
        mutate.header("x-user-id", validateResultMap.get("userid"));
        mutate.header("x-user-name", validateResultMap.get("user"));
        mutate.header("x-user-serviceName", serviceName);
        ServerHttpRequest buildReuqest = mutate.build();

        //todo 如果响应中需要放数据，也可以放在response的header中
        //ServerHttpResponse response = exchange.getResponse();
        //response.getHeaders().add("new_token","token_value");
        return chain.filter(exchange.mutate().request(buildReuqest).build());
    }



}

4- 编写相关接口API

package spring.cloud.gateway.controller;

import org.springframework.web.bind.annotation.*;
import spring.cloud.gateway.common.JwtUtil;

import java.util.Map;

@RestController
@RequestMapping("/token")
public class TokenController {

    /**
     * 登录接口
     * @param user（userID +pwd）
     * @return
     */
    @PostMapping("/userId/pwd")
    public String getToken(@RequestBody Map<String,String> user)  {
        //用户名密码需要加密处理
        String result = "";
        if (user == null || user.isEmpty()) {
            return result;
        }
        String userId = user.get("userId");
        String pwd = user.get("pwd");
        if (!doLogin(userId,pwd)) {
            return result;
        }
        String token = JwtUtil.generateToken(userId);
        // todo 将token放入redis中，设置超时时间为 2 * t
        return token;
    }

    private Boolean doLogin(String userId,String pwd) {
        //后续对接user表验证
        if ("admin".equals(userId) && "123".equals(pwd)) {
            return true;
        }
        if ("spring".equals(userId) && "123".equals(pwd)) {
            return true;
        }
        if ("gateway".equals(userId) && "123".equals(pwd)) {
            return true;
        }
        return false;
    }

    /**
     * 登出接口
     */




    /**
     * 刷新token的接口
     * 在刷新前校验userId和token是否匹配
     */


}