【Spring Cloud】feign调用携带token

在Feign中携带Token进行调用，可以通过定义一个Feign的拦截器来实现。以下是一个简单的示例：

1. 首先，创建一个Feign的拦截器：

import feign.RequestInterceptor;
import feign.RequestTemplate;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
 
import javax.servlet.http.HttpServletRequest;
 
public class FeignTokenInterceptor implements RequestInterceptor {
    @Override
    public void apply(RequestTemplate template) {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        if (attributes != null) {
            HttpServletRequest request = attributes.getRequest();
            String token = request.getHeader("Authorization"); // 假设token在请求头的Authorization字段
            template.header("Authorization", token); // 添加token到请求头
        }
    }
}

2. 然后，在Feign客户端配置中添加这个拦截器：

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
 
@FeignClient(name = "service-provider", url = "http://localhost:8080", configuration = FeignClientConfig.class)
public interface ServiceProviderClient {
    @GetMapping("/api/resource")
    String getResource();
}
 
import feign.RequestInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
@Configuration
public class FeignClientConfig {
    @Bean
    public RequestInterceptor requestInterceptor() {
        return new FeignTokenInterceptor();
    }
}

在这个示例中，FeignTokenInterceptor拦截器会从当前请求中取出Authorization头部的值，并将其添加到Feign客户端发起的每个请求中。这样，Feign客户端在调用远程服务时就会携带上token了。