解决在微服务环境下远程调用feign和异步线程存在请求数据丢失问题
时间:2023-03-09 12:09:28|栏目:JAVA代码|点击: 次
一、无异步线程得情况下feign远程调用:
1、登录拦截器:
@Component public class LoginUserInterceptor implements HandlerInterceptor { public static ThreadLocal<MemberResVo> loginUser = new ThreadLocal<>(); @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { //获取登录用户的键 MemberResVo attribute = (MemberResVo) request.getSession().getAttribute(AuthServerConstant.LONG_USER); if (attribute!=null){ loginUser.set(attribute); return true; }else { request.getSession().setAttribute("msg","请先进行登录!"); response.sendRedirect("http://auth.gulimall.com/login.html"); return false; } } }
2.问题示例图:
3.解决方法:
import feign.RequestInterceptor; import feign.RequestTemplate; 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.HttpServletRequest; @Configuration public class GuliFeignConfig { //fegin过滤器 @Bean("requestInterceptor") public RequestInterceptor requestInterceptor() { return new RequestInterceptor() { public void apply(RequestTemplate template) { //上下文环境保持器,拿到刚进来这个请求包含的数据,而不会因为远程数据请求头被清除 ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes(); HttpServletRequest request = attributes.getRequest();//老的请求 if (request != null) { //同步老的请求头中的数据,这里是获取cookie String cookie = request.getHeader("Cookie"); template.header("Cookie", cookie); } } }; } }
二、异步情况下丢失上下文问题:
① 在同一线程下进行远程调用,即一连串调用的情况下OrederService通过远程调用先查找adress信息,再查找cart信息,则仅需配置GuliFeignConfig就够了
② 由于采用的异步任务,所以101、102线程在自己的线程中调用登录拦截器interceptor,而其实只有在72号线程中登陆拦截器才进行放行(有请求头数据),这就导致101、102的request为null
解决方式(高亮部分):从总线中获取request数据放入子线程中
RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes()
@Service("orderService") public class OrderServiceImpl extends ServiceImpl<OrderDao, OrderEntity> implements OrderService { @Autowired MemberFeignService memberFeignService; @Autowired CartFeginService cartFeginService; @Autowired ThreadPoolExecutor executor; @Autowired WmsFeignService wmsFeignService; /** * 订单确认页返回的数据 * @return */ @Override public OrderConfirmVo confirmOrder() throws ExecutionException, InterruptedException { OrderConfirmVo confirmVo = new OrderConfirmVo(); MemberResVo memberResVo = LoginUserInterceptor.loginUser.get(); //从主线程中获得所有request数据 RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes(); CompletableFuture<Void> getAddressFuture = CompletableFuture.runAsync(() -> { //1、远程查询所有地址列表 RequestContextHolder.setRequestAttributes(requestAttributes); List<MemberAddressVo> address = memberFeignService.getAddress(memberResVo.getId()); confirmVo.setAddress(address); }, executor); //2、远程查询购物车所选的购物项,获得所有购物项数据 CompletableFuture<Void> cartFuture = CompletableFuture.runAsync(() -> { //放入子线程中request数据 RequestContextHolder.setRequestAttributes(requestAttributes); List<OrderItemVo> items = cartFeginService.getCurrentUserCartItems(); confirmVo.setItem(items); }, executor).thenRunAsync(()->{ RequestContextHolder.setRequestAttributes(requestAttributes); List<OrderItemVo> items = confirmVo.getItem(); List<Long> collect = items.stream().map(item -> item.getSkuId()).collect(Collectors.toList()); //远程调用查询是否有库存 R hasStock = wmsFeignService.getSkusHasStock(collect); //形成一个List集合,获取所有物品是否有货的情况 List<SkuStockVo> data = hasStock.getData(new TypeReference<List<SkuStockVo>>() { }); if (data!=null){ //收集起来,Map<Long,Boolean> stocks; Map<Long, Boolean> map = data.stream().collect(Collectors.toMap(SkuStockVo::getSkuId, SkuStockVo::getHasStock)); confirmVo.setStocks(map); } },executor); //feign远程调用在调用之前会调用很多拦截器,因此远程调用会丢失很多请求头 //3、查询用户积分 Integer integration = memberResVo.getIntegration(); confirmVo.setIntegration(integration); //其他数据自动计算 CompletableFuture.allOf(getAddressFuture,cartFuture).get(); return confirmVo; } }
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本文标题:解决在微服务环境下远程调用feign和异步线程存在请求数据丢失问题
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