一、无异步线程得情况下feign远程调用：
1、登录拦截器：
点击查看代码
@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：
点击查看代码
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();点击查看代码
@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;
}
}