如何通过Spring Feign Client传递认证Bearer Token

方法1：手动在Feign方法中传递请求头 #

直接在Feign接口的方法参数里添加@RequestHeader注解，调用时从当前请求中获取Token传入：

修改你的Feign接口：

@FeignClient("employee")
public interface EmployeeFeignClient {

    @RequestMapping(
        method= RequestMethod.GET,
        value="/employee/code/{code}",
        consumes="application/json"
    )
    EmployeeResponseEntity getEmployeeByCode(
        @PathVariable("code") String code,
        @RequestHeader("Authorization") String authorizationHeader
    );
}

调用时从当前请求获取Token：

// 注入HttpServletRequest获取当前请求头
@Autowired
private HttpServletRequest request;

public void queryEmployee(String empCode) {
    String bearerToken = request.getHeader("Authorization");
    employeeFeignClient.getEmployeeByCode(empCode, bearerToken);
}

方法2：全局Feign拦截器自动传递 #

通过实现RequestInterceptor，自动从当前请求上下文提取Token并添加到Feign请求头中，无需修改每个Feign方法：

创建拦截器类：

import feign.RequestInterceptor;
import feign.RequestTemplate;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;

@Component
public class FeignAuthInterceptor implements RequestInterceptor {

    @Override
    public void apply(RequestTemplate template) {
        // 从请求上下文获取当前请求
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        if (attributes != null) {
            HttpServletRequest request = attributes.getRequest();
            String authToken = request.getHeader("Authorization");
            // 如果Token存在，添加到Feign请求头
            if (authToken != null) {
                template.header("Authorization", authToken);
            }
        }
    }
}

这个拦截器会被Spring自动识别，所有Feign调用都会自动带上当前请求的Authorization头。

注意事项 #

如果你的调用是在异步线程中执行，RequestContextHolder可能无法获取到请求上下文，此时需要手动传递请求属性，或者在异步方法中重新设置上下文。

内容的提问来源于stack exchange，提问作者Toji