Spring Boot的Gateway服务将Session信息保存在Redis示例

1、添加依赖
xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
    </dependency>
    <dependency>
        <groupId>io.lettuce</groupId>
        <artifactId>lettuce-core</artifactId>
    </dependency>
</dependencies>
2、配置Redis连接
yaml
spring:
  redis:
    host: localhost
    port: 6379
3、创建过滤器，拦截所有请求并将session封装好存储到Redis中
java
import io.lettuce.core.RedisClient;
import io.lettuce.core.api.StatefulRedisConnection;
import org.springframework.beans.factory.annotation.Autowired;
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.core.Ordered;
import org.springframework.http.HttpCookie;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.util.UUID;

@Component
public class RedisSessionFilter implements GlobalFilter, Ordered {

    private final RedisClient redisClient;

    @Autowired
    public RedisSessionFilter(RedisClient redisClient) {
        this.redisClient = redisClient;
    }

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        Route route = (Route) exchange.getAttributes().get(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR);

        String session_id = null;
        HttpCookie cookie = request.getCookies().getFirst("session_id");
        if (cookie != null) {
            session_id = cookie.getValue();
        }

        if (session_id == null || !redisClient.connect().sync().exists(session_id)) {
            session_id = UUID.randomUUID().toString();
        }

        RedisSession session = new RedisSession(session_id, redisClient);
        exchange.getAttributes().put("session", session);

        return chain.filter(exchange).then(Mono.fromRunnable(() -> session.save(redisClient)));
    }

    @Override
    public int getOrder() {
        return Ordered.LOWEST_PRECEDENCE;
    }
}
4、创建RedisSession类，封装Session数据
java
import io.lettuce.core.RedisClient;
import io.lettuce.core.api.StatefulRedisConnection;

public class RedisSession {

    private final String session_id;
    private final StatefulRedisConnection<String, String> connection;

    public RedisSession(String session_id, RedisClient redisClient) {
        this.session_id = session_id;
        this.connection = redisClient.connect();
    }

    public void save(RedisClient redisClient) {
        connection.sync().set(session_id, "session data");
        connection.close();
    }
}
注：在实际应用中，需要根据需求修改RedisSession类的属性和方法。

5、Redis配置
在application.yaml文件中添加Redis相关的配置信息：

yaml
spring:
  redis:
    host: localhost
    port: 6379
lettuce:
  pool:
    max-active: 8
    max-wait: -1ms
    max-idle: 8
    min-idle: 0
6、启动Gateway服务
启动Gateway服务后，就可以在访问各个微服务的过程中将Session信息保存在Redis中了。