SpringCloud学习（八）-- Gateway服务引入

一时失言乱红尘 2022-12-26 13:29 110阅读 0赞

# 1，引入必要的包 #

<dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-gateway</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            </dependency>
        </dependencies>

# 2，编写配置文件 #

server:
      port: 10010
    
    spring:
      application:
        name: api-gateway
      cloud:
        gateway:
          routes:
            - id: user-service-route  #路由id
              #uri: http://127.0.0.1:9091 #代理的服务地址
              uri: lb://user-service #lb 从Eureka中获取具体的服务
              predicates: #路由断言：可以匹配映射路径
                - Path=/user/**
    
    eureka:
      client:
        service-url:
          defaultZone: http://127.0.0.1:10086/eureka,http://127.0.0.1:10087/eureka
      instance:
        prefer-ip-address: true
        ip-address: 127.0.0.1

# 3，启动类 #

@SpringBootApplication
    @EnableDiscoveryClient//启用Eureka注册中心
    public class GatewayApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(GatewayApplication.class,args);
        }
    }

# 4，添加默认路由器： #

全局和局部如下

spring:
      application:
        name: api-gateway
      cloud:
        gateway:
          routes:
            - id: user-service-route  #路由id
              #uri: http://127.0.0.1:9091 #代理的服务地址
              uri: lb://user-service #lb 从Eureka中获取具体的服务
              predicates: #路由断言：可以匹配映射路径
                - Path=/**
              filters: #局部路由过滤器
                - PrefixPath=/user #添加请求路径的前缀
          default-filters: #全局路由过滤器
            - AddResponseHeader=X-Reponse-Foo,Bar

# 5，添加自定义局部过滤器 #

通过观察gateway服务自带的默认路由器，发现都是继承一个 AbstractGatewayFilterFactory的类，如下图所示

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2E4MEM1MQ_size_16_color_FFFFFF_t_70][]

所以，我们的自定义局部过滤器也如此实现

## 1）添加配置文件 ##

spring:
      application:
        name: api-gateway
      cloud:
        gateway:
          routes:
            - id: user-service-route  #路由id
              #uri: http://127.0.0.1:9091 #代理的服务地址
              uri: lb://user-service #lb 从Eureka中获取具体的服务
              predicates: #路由断言：可以匹配映射路径
                - Path=/**
              filters: #局部路由过滤器
                - PrefixPath=/user #添加请求路径的前缀
                - MyParam=name #添加自定义过滤器
          default-filters: #全局路由过滤器
            - AddResponseHeader=X-Reponse-Foo,Bar

## 2）实现自定义过滤器 ##

package com.wayne.filter;
    
    import org.springframework.cloud.gateway.filter.GatewayFilter;
    import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
    import org.springframework.http.server.reactive.ServerHttpRequest;
    import org.springframework.stereotype.Component;
    
    import java.util.Arrays;
    import java.util.List;
    
    @Component
    public class MyParamGatewayFilterFactory extends AbstractGatewayFilterFactory<MyParamGatewayFilterFactory.Config> {
    
        final static String PARAM_NAME = "param";
    
        public MyParamGatewayFilterFactory(){
            super(Config.class);
        }
    
        public List<String> shortcutFieldOrder(){
            return Arrays.asList(PARAM_NAME);
        }
    
        @Override
        public GatewayFilter apply(Config config) {
            return ((exchange, chain) -> {
                ServerHttpRequest request = exchange.getRequest();
                if(request.getQueryParams().containsKey(config.param)){
                    request.getQueryParams().get(config.param)
                            .forEach(value -> System.out.printf("----局部过滤器---%s = %s---\n",config.param,value));
                }
    
                return chain.filter(exchange);
            });
        }
    
        public static class Config{
            private String param;
    
            public Config(){
    
            }
    
            public String getParam() {
                return param;
            }
    
            public void setParam(String param) {
                this.param = param;
            }
        }
    }

# 7，配置全局过滤器 #

全局过滤器直接用即可，实现GlobalFilter接口。如果对过滤器的顺序有要求，可同时实现 Ordered接口

package com.wayne.filter;
    
    import org.apache.commons.lang.StringUtils;
    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.stereotype.Component;
    import org.springframework.web.server.ServerWebExchange;
    import reactor.core.publisher.Mono;
    
    @Component
    public class TokenCheckFilter implements GlobalFilter, Ordered {
        @Override
        public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
    
            System.out.println("--------这个是全局过滤器MyGlobalFilter-----");
            String token = exchange.getRequest().getQueryParams().getFirst("token");
    
            if(StringUtils.isBlank(token)){
                exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);
                return exchange.getResponse().setComplete();
            }
    
            return chain.filter(exchange);
        }
    
        @Override
        public int getOrder() {
            //值越小，越优先
            return 1;
        }
    }

# 6，测试 #

浏览器输入 [http://127.0.0.1:10010/1?name=Wyane&token=abd][http_127.0.0.1_10010_1_name_Wyane_token_abd]

出现如下信息

![20201205213132671.png][]

控制台

![20201205223305336.png][]

如果没有加token，则浏览器出现401错误

![20201205224641442.png][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2E4MEM1MQ_size_16_color_FFFFFF_t_70]: /images/20221120/7efd043225bd4f93b3992716ca284a2f.png
[http_127.0.0.1_10010_1_name_Wyane_token_abd]: http://127.0.0.1:10010/1?name=Wyane&token=abd
[20201205213132671.png]: /images/20221120/5f892eeafb324906985b65b9bfe1afbe.png
[20201205223305336.png]: /images/20221120/fe6c839339f643c8b7b719f87927dfab.png
[20201205224641442.png]: https://img-blog.csdnimg.cn/20201205224641442.png