bean named 'departmentController' is defined

DepartmentController.java

package com.imooc.sm.controller;

import com.imooc.sm.entity.Department;
import com.imooc.sm.service.DepartmentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

@Controller("departmentController")
public class DepartmentController {
   @Autowired
   private DepartmentService departmentService;
   //  /department/list.do     /department_list.jsp
   public void list(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       List<Department > list = departmentService.getAll();
       request.setAttribute("LIST",list);
       request.getRequestDispatcher("../department_list.jsp").forward(request,response);
   }

   public void toAdd(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       request.getRequestDispatcher("../department_add.jsp").forward(request,response);
   }
   public void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       String name = request.getParameter("name");
       String address = request.getParameter("address");

       Department department = new Department();
       department.setName(name);
       department.setAddress(address);

       departmentService.add(department);
       response.sendRedirect("list.do");
   }

   public void toEdit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       Integer id = Integer.parseInt(request.getParameter("id"));
       Department department = departmentService.get(id);
       request.setAttribute("OBJ",department);
       request.getRequestDispatcher("../department_edit.jsp").forward(request,response);
   }
   public void edit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       Integer id = Integer.parseInt(request.getParameter("id"));
       String name = request.getParameter("name");
       String address = request.getParameter("address");

       Department department = new Department();
       department.setId(id);
       department.setName(name);
       department.setAddress(address);

       departmentService.edit(department);
       response.sendRedirect("list.do");
   }
   public void remove(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       Integer id = Integer.parseInt(request.getParameter("id"));
       departmentService.remove(id);
       response.sendRedirect("list.do");
   }
}