Springboot feign transfer request information

The underlying implementation

requestInterceptor implementation class to add information

public class NativeFeignConf {
    @Bean
    public RequestInterceptor getRequestInterceptor(){
        return new RequestInterceptor() {
            @Override
            public void apply(RequestTemplate requestTemplate) {
                ServletRequestAttributes servletRequestAttributes=(ServletRequestAttributes)RequestContextHolder.currentRequestAttributes();
                HttpServletRequest req=servletRequestAttributes.getRequest();
                Map<String,Collection<String>> headerMap=new HashMap();
                //获取你需要传递的头信息
                String myHeaderVal=req.getHeader("myHeader");
                headerMap.put("myHeader",Arrays.asList(myHeaderVal));
                //feign请求时，便可携带上该信息
                requestTempalte.headers(headerMap);
    }
}

feign join the config

@FeignClient(
    value="target-service",
    configuration=NativeFeignConf.class //加入该配置
)
public interface MyFeign(){
    ...
} 

In the case of open Hystrix

After opening hystrix, feign request, runs in another thread hystrix management.

So RequestContextHolder.currentRequestAttributes()not get value.

Solution:

Hystrix create a custom thread policy , we will servletRequestAttributespass the new thread, and assigned RequestContextHolder:

public class MyHystrixConcurrencyStrategy extends HystrixConcurrencyStrategy{
    @Override
    public <T> Callable<T> wrapCallable(Callable<T> callable){
        ServletRequestAttributes servletRequestAttributes=(ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        return new Callable<T>() {
            @Override
            public T call() throws Exception {
                try {
                    if (null != servletRequestAttributes) {
                        RequestContextHolder.setRequestAttributes(servletRequestAttributes);
                    }
                    return callable.call();
                }finally {
                    RequestContextHolder.resetRequestAttributes();
                }
            }
        };
    }
}

The registration policy

@Configuration
public class HystrixConfig{
    @PostConstruct
    public void init(){
        HystrixPlugins.getInstance().registerConcurrencyStrategy(
            new MyHystrixConcurrencyStrategy()
        )
    }
}

End.