执行后台管理分页查询功能点不能获取商品列表，报500空指针异常

Question

执行功能点：后台管理分页查询商品列表功呢点

运行报错：
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:981)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:860)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:845)
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:121)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

root cause

java.lang.NullPointerException
cn.e3mall.controller.ItemController.getItemList(ItemController.java:42)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:222)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)

经查找错误位置 ItemController.java:42) 估计此处为空值

功能点代码
controller web层


@RequestMapping("/item/list")
@ResponseBody
 public EasyUIDataGridResult getItemList(Integer page,Integer rows){
    //调用服务查询商品列表               
     EasyUIDataGridResult result = itemService.getItemList(page, rows);   此处为.java:42    空值
      return result;
   }
}

service 服务层

 @Autowired
private TbItemMapper itemMapper;


    @Override
public EasyUIDataGridResult getItemList(int page, int rows) {
       //设置分页信息
      PageHelper.startPage(page, rows);
      //执行查询
      TbItemExample example = new TbItemExample();
      List<TbItem> list = itemMapper.selectByExample(example);
      //创建一个返回值对象
      EasyUIDataGridResult result = new EasyUIDataGridResult();
      result.setRows(list);
      //取分页结果
      PageInfo<TbItem> pageInfo = new PageInfo<>(list);
      long total = pageInfo.getTotal();
      result.setTotal(total);
      return result;
}

请求支援 GG all

Answer 1

空指针异常肯定是itemService为null了，应该是你的itemService没有赋值吧，看看是不是自动装配的问题