Feign调用服务时丢失Cookie和Header信息的解决方案

2024-04-02 19:04:59 355人浏览泡泡鱼

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摘要

目录Feign调用服务丢失Cookie和Header信息服务调用方服务接受方Feign调用存在的问题①feign远程调用丢失请求头②异步调用Feign丢失上下文问题Feign调用服务

Feign调用服务丢失Cookie和Header信息

今天在使用Feign调用其他微服务的接口时，发现了一个问题：因为我的项目采用了无状态登录，token信息是存放在cookie中的，所以调用接口时，因为cookie中没有token信息，我的请求被拦截器拦截了。

参考几篇文章，靠谱的解决方法是：将cookie信息放到请求头中，再进行调用接口时，拦截器中可以对请求头进行解析，获取cookie信息

服务调用方

package top.codekiller.manager.upload.config;
import feign.RequestInterceptor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.WEB.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import javax.servlet.Http.Cookie;
import javax.servlet.http.httpservletRequest;
import java.util.Enumeration;

@Configuration
@Slf4j
public class FeignHeaderConfiguration {
    @Bean
    public RequestInterceptor requestInterceptor() {
        return requestTemplate -> {
            ServletRequestAttributes attrs = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
            if (attrs != null) {
                HttpServletRequest request = attrs.getRequest();
                // 如果在Cookie内通过如下方式取
                Cookie[] cookies = request.getCookies();
                if (cookies != null && cookies.length > 0) {
                    for (Cookie cookie : cookies) {
                        requestTemplate.header(cookie.getName(), cookie.getValue());
                        System.out.println("信息"+cookie.getName()+cookie.getValue());
                    }
                } else {
                    log.warn("FeignHeadConfiguration", "获取Cookie失败！");
                }
                
                // 如果放在header内通过如下方式取
                Enumeration<String> headerNames = request.getHeaderNames();
                if (headerNames != null) {
                    while (headerNames.hasMoreElements()) {
                        String name = headerNames.nextElement();
                        String value = request.getHeader(name);
                        
                        if ("jsessionid".equalsIgnoreCase(name)) {
                            log.debug("添加自定义请求头key:" + name + ",value:" + value);
                            requestTemplate.header(name, value);
                        } else {
                            log.debug("FeignHeadConfiguration", "非自定义请求头key:" + name + ",value:" + value + "不需要添加!");
                        }
                    }
                } else {
                    log.warn("FeignHeadConfiguration", "获取请求头失败！");
                }
            }
        };
    }
}

服务接受方

//有些请求时从通过feign进行请求的，这一部分请求时不包含cookie信息的，因此我们要从请求头中获取
            Enumeration<String> headerNames = request.getHeaderNames();
            if (headerNames != null) {
                while (headerNames.hasMoreElements()) {
                    String name = headerNames.nextElement();
                    String value = request.getHeader(name);
                    System.out.println("header的信息"+name+"::::"+value);
                    if(name.equalsIgnoreCase("MC_TOKEN")){  //注意这里变成了小写
                        token=value;
                    }
                }
            }

运行的时候，我发现请求还是被拦截了，看了下打印信息，发现我的MC_TOKEN变成了小写，所以在字符串进行比较的时候要忽略大小写。

以下为扩展，仅仅记录一下

这样仍然有个问题：

在开启熔断器之后，方法里的attrs是null，因为熔断器默认的隔离策略是thread，也就是线程隔离，实际上接收到的对象和这个在发送给B不是一个线程，怎么办？

有一个办法，修改隔离策略hystrix.command.default.execution.isolation.strategy=SEMAPHORE，改为信号量的隔离模式，但是不推荐，因为thread是默认的，而且要命的是信号量模式，熔断器不生效，比如设置了熔断时间。

另一个办法：重写Feign的隔离策略

import com.netflix.hystrix.HystrixThreadPoolKey;
import com.netflix.hystrix.HystrixThreadPoolProperties;
import com.netflix.hystrix.strategy.HystrixPlugins;
import com.netflix.hystrix.strategy.concurrency.HystrixConcurrencyStrategy;
import com.netflix.hystrix.strategy.concurrency.HystrixRequestVariable;
import com.netflix.hystrix.strategy.concurrency.HystrixRequestVariableLifecycle;
import com.netflix.hystrix.strategy.eventnotifier.HystrixEventNotifier;
import com.netflix.hystrix.strategy.executionhook.HystrixCommandExecutionHook;
import com.netflix.hystrix.strategy.metrics.HystrixMetricsPublisher;
import com.netflix.hystrix.strategy.properties.HystrixPropertiesStrategy;
import com.netflix.hystrix.strategy.properties.HystrixProperty;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
 
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
 

@Component
public class FeignHystrixConcurrencyStrategyIntellif extends HystrixConcurrencyStrategy {
 
    private static final Logger log = LoggerFactory.getLogger(FeignHystrixConcurrencyStrategyIntellif.class);
    private HystrixConcurrencyStrategy delegate;
 
    public FeignHystrixConcurrencyStrategyIntellif() {
        try {
            this.delegate = HystrixPlugins.getInstance().getConcurrencyStrategy();
            if (this.delegate instanceof FeignHystrixConcurrencyStrategyIntellif) {
                // Welcome to singleton hell...
                return;
            }
            HystrixCommandExecutionHook commandExecutionHook =
                    HystrixPlugins.getInstance().getCommandExecutionHook();
            HystrixEventNotifier eventNotifier = HystrixPlugins.getInstance().getEventNotifier();
            HystrixMetricsPublisher metricsPublisher = HystrixPlugins.getInstance().getMetricsPublisher();
            HystrixPropertiesStrategy propertiesStrategy =
                    HystrixPlugins.getInstance().getPropertiesStrategy();
            this.loGCurrentStateOfHystrixPlugins(eventNotifier, metricsPublisher, propertiesStrategy);
            HystrixPlugins.reset();
            HystrixPlugins.getInstance().reGISterConcurrencyStrategy(this);
            HystrixPlugins.getInstance().registerCommandExecutionHook(commandExecutionHook);
            HystrixPlugins.getInstance().registerEventNotifier(eventNotifier);
            HystrixPlugins.getInstance().registerMetricsPublisher(metricsPublisher);
            HystrixPlugins.getInstance().registerPropertiesStrategy(propertiesStrategy);
        } catch (Exception e) {
            log.error("Failed to register Sleuth Hystrix Concurrency Strategy", e);
        }
    }
 
    private void logCurrentStateOfHystrixPlugins(HystrixEventNotifier eventNotifier,
                                                 HystrixMetricsPublisher metricsPublisher, HystrixPropertiesStrategy propertiesStrategy) {
        if (log.isDebugEnabled()) {
            log.debug("Current Hystrix plugins configuration is [" + "concurrencyStrategy ["
                    + this.delegate + "]," + "eventNotifier [" + eventNotifier + "]," + "metricPublisher ["
                    + metricsPublisher + "]," + "propertiesStrategy [" + propertiesStrategy + "]," + "]");
            log.debug("Registering Sleuth Hystrix Concurrency Strategy.");
        }
    }
 
    @Override
    public <T> Callable<T> wrapCallable(Callable<T> callable) {
        RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
        return new WrappedCallable<>(callable, requestAttributes);
    }
 
    @Override
    public ThreadPoolExecutor getThreadPool(HystrixThreadPoolKey threadPoolKey,
                                            HystrixProperty<Integer> corePoolSize, HystrixProperty<Integer> maximumPoolSize,
                                            HystrixProperty<Integer> keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue) {
        return this.delegate.getThreadPool(threadPoolKey, corePoolSize, maximumPoolSize, keepAliveTime,
                unit, workQueue);
    }
 
    @Override
    public ThreadPoolExecutor getThreadPool(HystrixThreadPoolKey threadPoolKey,
                                            HystrixThreadPoolProperties threadPoolProperties) {
        return this.delegate.getThreadPool(threadPoolKey, threadPoolProperties);
    }
 
    @Override
    public BlockingQueue<Runnable> getBlockingQueue(int maxQueueSize) {
        return this.delegate.getBlockingQueue(maxQueueSize);
    }
 
    @Override
    public <T> HystrixRequestVariable<T> getRequestVariable(HystrixRequestVariableLifecycle<T> rv) {
        return this.delegate.getRequestVariable(rv);
    }
 
    static class WrappedCallable<T> implements Callable<T> {
        private final Callable<T> target;
        private final RequestAttributes requestAttributes;
 
        public WrappedCallable(Callable<T> target, RequestAttributes requestAttributes) {
            this.target = target;
            this.requestAttributes = requestAttributes;
        }
 
        @Override
        public T call() throws Exception {
            try {
                RequestContextHolder.setRequestAttributes(requestAttributes);
                return target.call();
            } finally {
                RequestContextHolder.resetRequestAttributes();
            }
        }
    }
}

然后使用默认的熔断器隔离策略，也可以在拦截器内获取到上游服务的请求头信息了；

Feign调用存在的问题

① feign远程调用丢失请求头

问题描述：

当远程调用其他服务时，设置了拦截器判断用户是否登录，但是结果是即使用户登录了，也会显示用户没登录，原因在于远程调用时，发送的请求是一个新的情求，请求中并不存在cookie，而原始请求中是携带cookie的。

解决方案如下：

@Configuration
public class MallFeignConfig {
    @Bean("requestInterceptor")
    public RequestInterceptor requestInterceptor() {
        RequestInterceptor requestInterceptor = template -> {
            //1、使用RequestContextHolder拿到刚进来的请求数据
            ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
            if (requestAttributes != null) {
                //老请求
                HttpServletRequest request = requestAttributes.getRequest();
                if (request != null) {
                    //2、同步请求头的数据（主要是cookie）
                    //把老请求的cookie值放到新请求上来，进行一个同步
                    String cookie = request.getHeader("Cookie");
                    template.header("Cookie", cookie);
                }
            }
        };
        return requestInterceptor;
    }
}

② 异步调用Feign丢失上下文问题

问题描述：

由于feign请求拦截器为新的request设置请求头底层是使用ThreadLocal保存刚进来的请求，所以在异步情况下，其他线程并不能获取到主线程的ThreadLocal，所以也拿不到请求。

解决：

先获取主线程的requestAttributes，再分别向其他线程中设置

RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
CompletableFuture.runAsync(() ->{
   RequestContextHolder.setRequestAttributes(requestAttributes);
});

以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。

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