SpringBoot Feign内部调用时自动带上请求头信息(header)

Posted 2021-08-28 我叫白小飞

我们在项目中单独使用feign时，有时候需要带上header，但是，手动添加header注释，或者在mapping里边写上header太麻烦，需要从请求里边取出来，然后再放到feign里边，下边介绍一种简单的方式：

@Configuration
public class FeignConf implements RequestInterceptor {
    private final ObjectFactory<HttpMessageConverters> messageConverters;

    public FeignConf(ObjectFactory<HttpMessageConverters> messageConverters) {
        this.messageConverters = messageConverters;
    }

    @Bean
    @Primary
    @Scope("prototype")
    public Encoder feignEncoder() {
        return new SpringFormEncoder(new SpringEncoder(messageConverters));
    }
    @Bean
    public Retryer feignRetarder(){
        return new Retryer.Default(100,SECONDS.toMillis(1),5);
    }

    @Bean
    Logger.Level feignLoggerLevel() {
        return Logger.Level.FULL;
    }

    @Override
    public void apply(RequestTemplate template) {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder
                .getRequestAttributes();
        assert attributes != null;
        HttpServletRequest request = attributes.getRequest();
        Enumeration<String> headerNames = request.getHeaderNames();
        if (headerNames != null) {
            while (headerNames.hasMoreElements()) {
                String name = headerNames.nextElement();
                String values = request.getHeader(name);
                template.header(name, values);
            }
        }
        Enumeration<String> bodyNames = request.getParameterNames();
		// 主要的就是以下这段代码，是将当前请求中的header取出来，放到第三方请求中去
        Request.Body body = template.requestBody();
        Map<String,Object> map = new HashMap<>(16);
        if (bodyNames != null) {
            while (bodyNames.hasMoreElements()) {
                String name = bodyNames.nextElement();
                String values = request.getParameter(name);
                map.put(name,values);
            }
            body.expand(map);
        }
        template.body(body);
    }
}