springcloud2 gateway 之三：使用filter作權限驗證

springcloud2 gateway 之一：簡單樣例
http://www.javashuo.com/article/p-nkplpein-np.html

springcloud2 gateway 之二：轉發調用eureka客戶端服務
https://blog.csdn.net/haveqing/article/details/88427571

文件結構

1、GatewayConfig.java

package com.urthink.upfs.springcloudgateway.config;

import com.urthink.upfs.springcloudgateway.filter.TokenFilter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class GatewayConfig {

    @Bean
    public TokenFilter tokenFilter(){
        return new TokenFilter();
    }
}

2、TokenFilter.java

每個GlobalFilter都做用在每個router上，可以知足大多數的需求。可是若是遇到業務上的定製，可能須要編寫知足本身需求的GlobalFilter。在下面的案例中將講述如何編寫本身GlobalFilter，該GlobalFilter會校驗請求中是否包含了請求參數「token」，如何不包含請求參數「token」則不轉發路由，不然執行正常的邏輯。代碼以下：

package com.urthink.upfs.springcloudgateway.filter;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpStatus;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

/**
 * gateway全局過濾器
 * https://blog.csdn.net/forezp/article/details/85057268
 */
public class TokenFilter implements GlobalFilter, Ordered {

    Logger logger= LoggerFactory.getLogger( TokenFilter.class );
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        String token = exchange.getRequest().getQueryParams().getFirst("token");
        if (token == null || token.isEmpty()) {
            logger.info( "token is empty..." );
            exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);
            return exchange.getResponse().setComplete();
        }
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return -100;
    }
}

在上面的TokenFilter須要實現GlobalFilter和Ordered接口，這和實現GatewayFilter很相似。而後根據ServerWebExchange獲取ServerHttpRequest，而後根據ServerHttpRequest中是否含有參數token，若是沒有則完成請求，終止轉發，不然執行正常的邏輯。

3、訪問

http://localhost:8080/app2/demo/test1

返回 401 Unauthorized

http://localhost:8080/app2/demo/test1?token=tokendata

正常返回數據

 

既然gateway已經鏈接到eureka，就能夠經過feign調用其餘服務，作更復雜的權限驗證了，而沒必要直接連數據庫。

 

參考：

spring cloud gateway之filter篇
https://blog.csdn.net/forezp/article/details/85057268

Spring-Cloud-Gateway之過濾器GatewayFilter
https://www.jianshu.com/p/eb3a67291050

spring cloud gateway 2 深刻了解 - filter
https://www.jianshu.com/p/5e40bbc95eb9

微服務架構spring cloud - Gateway過濾器（十二）
https://blog.csdn.net/m0_37834471/article/details/82621337