HTTP Status 500 - Request processing failed； nested exception is java.lang.NullPointerException

做青橙电商项目的时候，发布项目后登录发现直接报空指针异常，仔细检查代码后发现是dubbo远程框架中service远程调用失败，问题是导包倒错了

报错如下：

HTTP Status 500 - Request processing failed; nested exception is java.lang.NullPointerException

type Exception report

message Request processing failed; nested exception is java.lang.NullPointerException

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)
	org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
	org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

解决办法：

其中@Reference需要的包不是import jdk.nashorn.internal.ir.annotations.Reference;

而是import com.alibaba.dubbo.config.annotation.Reference

修改后问题解决

package com.qingcheng.controller;

import com.qingcheng.pojo.goods.Brand;
import com.qingcheng.service.goods.BrandService;
import jdk.nashorn.internal.ir.annotations.Reference;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/brand")
public class BrandController {

    @Reference
    private BrandService brandService;

    @RequestMapping("/findAll")
    public List<Brand> findAll(){
          return brandService.findAll();
    }

}