Spring网关Redis会话存储类型-保存问题

Question

我有一个微服务架构中的spring网关。

当请求到达网关时，它必须以下面提到的方式进行操作

1. 创建会话并设置属性
2. 在redis中保存会话
3. 将请求路由到Microservice B
4. Microservice B接收会话ID并从会话获取属性

在尝试实现这一点时，（第2点）保存会话ID的操作发生在调用microservices B并返回其响应（第4点）之后。（即第2点发生在第4点之后）。

但是，在请求被路由到应用程序B之前，sessionId应该保存在redis中。

网关应用程序

应用yml

server:
  port: 4000
spring:
  cloud:
    gateway:
      routes:
      - id: demo-app1
        uri: http://localhost:4001/demo-app1
        predicates:
        - Path=/demo-app1/**
        filters:
        - SaveSession
        - CustomSessionHandle
        - name: Retry
          args:
            retries: 2
            statuses: BAD_GATEWAY
            methods: GET,POST
            backoff:
              firstBackoff: 10ms
              maxBackoff: 50ms
              factor: 2
              basedOnPreviousValue: false

  session:
    store-type: redis             # Defines where the session is stored JVM or redis
    redis:
      flush-mode: immediate      #Tells spring to flush the session data immediately into redis
  redis:
    host: 127.0.0.1
    port: 6379

@Component
public class CustomRequestFilter implements GatewayFilter, Ordered {

    @Override
    public int getOrder() {
        return -1;
    }

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        Map<String, Object> sessionMap = new HashMap<>();
        sessionMap.put("param", "Hi, I am the value from cloud gateway");    

        return exchange.getSession().doOnNext(webSession -> webSession.getAttributes().putAll(sessionMap))).then(chain.filter(
                exchange));
    }

   
}

@Component
public class CustomSessionHandle extends AbstractGatewayFilterFactory<Object> {

    @Override
    public GatewayFilter apply(Object config) {
        return new CustomRequestFilter();
    }

}

POM文件--

<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.session</groupId>
            <artifactId>spring-session-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-sleuth</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis-reactive</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.zalando</groupId>
            <artifactId>logbook-spring-boot-starter</artifactId>
            <version>${logbook-spring-boot-starter}</version>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

Answer 1

try this: 

@Component
@Slf4j
public class CustomWebFilter implements WebFilter, Ordered {
    @Value("${ss.apigateway.context.path}")
    private String contextPath;

    @Override
    public Mono<Void> filter(ServerWebExchange serverWebExchange,
                             WebFilterChain webFilterChain) {
        String path = serverWebExchange.getRequest().getURI().getPath().
                replace(contextPath, "");

        log.debug("Old Path: '{}', Modified Path: '{}'",
                serverWebExchange.getRequest().getURI().getPath(), path);

        ServerHttpRequest updatedHttpRequest = serverWebExchange.getRequest().mutate().path(path).build();
        return webFilterChain.filter(serverWebExchange.mutate().request(updatedHttpRequest).build());
    }

    @Override
    public int getOrder() {
        return Ordered.HIGHEST_PRECEDENCE;
    }
}

Answer 2

您可以使用@order注释来提到筛选器的顺序