spring-boot - 如何防止 Redis 写入匿名用户 session

Question

我有这个示例应用程序:

package com.example.session;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.session.data.redis.config.annotation.web.http.EnableRedisHttpSession;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
public class DemoRedisDataSessionApplication {

    @Configuration
    @EnableWebSecurity
    @EnableRedisHttpSession(redisNamespace = "demo-redis-data-session")
    public static class AppConfiguration extends WebSecurityConfigurerAdapter {

        @Override
        protected void configure(AuthenticationManagerBuilder auth) throws Exception {
            auth.inMemoryAuthentication().withUser("user").password("0000").roles("USER");
        }

        @Override
        protected void configure(HttpSecurity http) throws Exception {
            http.formLogin().and()
                    .authorizeRequests().antMatchers("/ping").permitAll().and()
                    .authorizeRequests().anyRequest().fullyAuthenticated();
        }

    }

    @RestController
    public static class AppController {
        @GetMapping("/ping")
        public String ping() {
            return "pong";
        }

        @GetMapping("/secured")
        public String secured() {
            return "secured";
        }
    }

    public static void main(String[] args) {
        SpringApplication.run(DemoRedisDataSessionApplication.class, args);
    }

}

当我点击 /secured我得到 302 重定向到 /login表单，如果我没有登录，这就是我所期望的，但是我在 Redis 中得到了一些不需要的条目:
127.0.0.1:6379> keys *
1) "spring:session:demo-redis-data-session:sessions:expires:dbb124b9-c37d-454c-8d67-409f28cb88a6"
2) "spring:session:demo-redis-data-session:expirations:1515426060000"
3) "spring:session:demo-redis-data-session:sessions:dbb124b9-c37d-454c-8d67-409f28cb88a6"

我不想为每个匿名用户(读取爬虫)创建这些数据，那么当匿名用户访问安全端点/页面时，有没有办法防止这些 Redis 条目？

用于此示例项目的其他数据

docker-compose.yml
version: "2"
services:
redis:
image: redis
ports:
- "6379:6379"

Spring 启动版本
1.5.9.RELEASE

Answer 1

这不是最佳解决方案，因为它只为所有爬虫创建一个 session ，但至少我没有让 Redis 充满不需要的 session 。

import lombok.extern.log4j.Log4j;
import org.springframework.session.Session;
import org.springframework.session.SessionRepository;
import org.springframework.session.web.http.CookieHttpSessionStrategy;
import org.springframework.session.web.http.MultiHttpSessionStrategy;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Log4j
@Component
public class CrawlerManagerSessionStrategyWrapper implements MultiHttpSessionStrategy {

    private CookieHttpSessionStrategy delegate;
    private volatile String crawlerSessionId;

    public CrawlerManagerSessionStrategyWrapper() {
        this.delegate = new CookieHttpSessionStrategy();
    }

    public String getRequestedSessionId(HttpServletRequest request) {
        String sessionId = getSessionIdForCrawler(request);
        if (sessionId != null)
            return sessionId;
        else {
            return delegate.getRequestedSessionId(request);
        }
    }

    public void onNewSession(Session session, HttpServletRequest request, HttpServletResponse response) {
        delegate.onNewSession(session, request, response);
        if (isCrawler(request)) {
            crawlerSessionId = session.getId();
        }
    }

    public void onInvalidateSession(HttpServletRequest request, HttpServletResponse response) {
        delegate.onInvalidateSession(request, response);
    }

    public HttpServletRequest wrapRequest(HttpServletRequest request, HttpServletResponse response) {
        return request;
    }

    public HttpServletResponse wrapResponse(HttpServletRequest request, HttpServletResponse response) {
        return response;
    }

    private String getSessionIdForCrawler(HttpServletRequest request) {
        if (isCrawler(request)) {
            SessionRepository<Session> repo = (SessionRepository<Session>) request.getAttribute(SessionRepository.class.getName());
            if (crawlerSessionId != null && repo != null) {
                Session session = repo.getSession(crawlerSessionId);
                if (session != null) {
                    return crawlerSessionId;
                }
            }
        }
        return null;
    }

    private boolean isCrawler(HttpServletRequest request) {
        // Here goes the logic to understand if the request comes from a crawler, for example by checking the user agent.
        return true;
    }

}

唯一要实现的是 isCrawler方法来说明请求是否来自爬虫。