spring_cloud_feign服务之间token传递

使用open-feign的拦截器

import feign.RequestInterceptor;
import feign.RequestTemplate;
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;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;

@Configuration
public class FeginInterceptor implements RequestInterceptor {
    @Override
    public void apply(RequestTemplate requestTemplate) {
       try {
           Map<String,String> headers = getHeaders();
           for(String headerName : headers.keySet()){
               requestTemplate.header(headerName, headers.get(headerName));
           }
       }catch (Exception e){
           e.printStackTrace();
       }
    }
    private Map<String, String> getHeaders(){
        HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        Map<String, String> map = new LinkedHashMap<>();
        Enumeration<String> enumeration = request.getHeaderNames();
        while (enumeration.hasMoreElements()) {
            String key = enumeration.nextElement();
            String value = request.getHeader(key);
            map.put(key, value);
        }
        return map;
    }

}

当不开启Hystrix时上面代码生效，当开启Hystrix后不生效，RequestContextHolder.getRequestAttributes()报空指针。这是因为Hystrix默认使用的线程隔离，就是开启一个线程去调用。RequestContextHolder.getRequestAttributes() 内部是使用的ThtreadLocal来获取的，所以需要把值传递给子线程。我们需要使用自定义HystrixConcurrencyStrategy来完成。

@Configuration
public class HystrixConfig {
    static {
        HystrixPlugins.getInstance().registerConcurrencyStrategy(new RequestContextHystrixConcurrencyStrategy());
    }
}

上面这个类是保证自定义类先于默认的策略类。

import com.netflix.hystrix.strategy.concurrency.HystrixConcurrencyStrategy;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;

import java.util.concurrent.Callable;


public class RequestContextHystrixConcurrencyStrategy extends HystrixConcurrencyStrategy {

    @Override
    public <T> Callable<T> wrapCallable(Callable<T> callable) {
        RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
        System.out.println("执行到这了");
        return () -> {
            try {
                RequestContextHolder.setRequestAttributes(requestAttributes);
                System.out.println("执行到这了2");
                return callable.call();
            } finally {
                RequestContextHolder.resetRequestAttributes();
            }
        };
    }
}

鉴权

鉴权是在gatwey网关项目调用认证鉴权中心项目做。获取到用户想访问的连接URL， 如果需要权限，用户有权限，可以访问，用户没有权限，返回无权限。如果地址不需要权限直接可以访问。