SpringCloud(六)Gateway网关

梦里梦外; 2022-01-30 01:37 320阅读 0赞

**目录**

一.Gateway网关说明

1.Gateway配置

2.Gateway拦截器

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# 一.Gateway网关说明 #

spring-cloud-Gateway是spring-cloud的一个子项目。而zuul则是netflix公司的项目，只是spring将zuul集成在spring-cloud中使用而已。  
还有一种说法是因为zuul2连续跳票和zuul1的性能表现不是很理想，所以催生了spring孵化Gateway项目。  
总的来说，gateway性能大大强于zuul。

## 1.Gateway配置 ##

首先在pom.xml文件中导入依赖

<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
    </dependency>

server:
      port: 8999
    spring:
      application:
        name: gateway
      cloud:
        gateway:
          discovery:
            locator:
              enabled: true
          routes:
            - id: feign-customer
            #lb://feign-customer
              uri: lb://feign-customer
              order: 0
              predicates:
                - Path=/foo/**
              filters:
                - StripPrefix=1
    logging:
      level:
        org.springframework.cloud.gateway: debug

表示注册中心生效，我们可以通过注册中心的服务名进行路由转发  
discovery.locator.enabled=true;  
表示路由ID  
\- id: feign-customer  
指向注册中心的服务。lb://服务ID或者http://localhost:8080完整的url  
uri: lb://feign-customer  
表示要进行的断言  
predicates:  
表示path地址，根据url，以foo开头的会被转发到feign-customer服务，可以使用通配符地址  
\- Path= /foo/\*\*  
过滤器  
filters:  
从前面截取一个，忽略第一个/foo,其他路径进行转发  
\- StripPrefix= 1

## 2.Gateway拦截器 ##

/**
     * @Author wangyu
     * @Description: Copyright  2019 yiYuan Networks 上海义援网络科技有限公司. All rights reserved.
     * @Date 2019/5/16
     */
    @Component
    public class WrapperResponseFilter implements GlobalFilter, Ordered {
        @Override
        public int getOrder() {
            // -1 is response write filter, must be called before that
            return -2;
        }
    
        @Override
        public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
            //前置拦截器
            ServerHttpResponse originalResponse = exchange.getResponse();
            DataBufferFactory bufferFactory = originalResponse.bufferFactory();
            ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {
                @Override
                public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
                    //后置拦截器
                    if (body instanceof Flux) {
                        Flux<? extends DataBuffer> fluxBody = (Flux<? extends DataBuffer>) body;
                        return super.writeWith(fluxBody.map(dataBuffer -> {
                            // probably should reuse buffers
                            byte[] content = new byte[dataBuffer.readableByteCount()];
                            dataBuffer.read(content);
                            // 释放掉内存
                            DataBufferUtils.release(dataBuffer);
                            String rs = new String(content, Charset.forName("UTF-8"));
                            Map<String,Object> response = new HashMap<>();
                            response.put("code","1");
                            response.put("message","请求成功");
                            response.put("data",rs);
    //                        byte[] newRs = JSON.toJSONString(response).getBytes(Charset.forName("UTF-8"));
    //                        originalResponse.getHeaders().setContentLength(newRs.length);//如果不重新设置长度则收不到消息。
                            //请求的返回结果
                            return bufferFactory.wrap(rs.getBytes());
                        }));
                    }
                    return super.writeWith(body);
                }
            };
            return chain.filter(exchange.mutate().response(decoratedResponse).build());
        }
    }