不明白这里？

package global;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import javax.servlet.GenericServlet;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class DispatcherServlet extends GenericServlet{

	private ApplicationContext applicationContext;
	
	
	public void init() throws ServletException {
		super.init();
		applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");
	}
	
	@Override
	public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
		
		HttpServletRequest request = (HttpServletRequest) servletRequest;
		
		HttpServletResponse response = (HttpServletResponse) servletResponse;
		
		/*
        staff/add.do        login.do
        staffController
        public void add(HttpServletRequest request, HttpServletResponse response){}
        *
		 */
		
		String path = request.getServletPath().substring(1);
		String beanName = null;
		String methodName = null;
		int index = path.indexOf("/");
		
		if(index!=-1) {
			beanName=path.substring(0,index)+"Controller";
			methodName = path.substring(index+1,path.indexOf(".do"));
		}else {
			beanName="staffController";
			methodName=path.substring(0,path.indexOf(".do"));
		}
		
		
		Object obj = applicationContext.getBean(beanName);
		
		try {
			Method method = obj.getClass().getMethod(methodName,HttpServletRequest.class,HttpServletResponse.class);
			method.invoke(obj,request,response);
		} catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
		
	}
			
}

package com.zrcx.controller;

import java.io.IOException;
import java.util.List;

import javax.annotation.Resource;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;

import com.zrcx.entity.Department;
import com.zrcx.service.DepartmentService;

@Controller("departmentController")
public class DepartmentController {
	
	//注入service
	@Resource
	private DepartmentService departmentService;
	
	// 	/department/list.do     /department_list.jsp
	
	//控制器
	public void list(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
		
		//欧所有部门信息
		List<Department> list = departmentService.getAll();
		request.setAttribute("LIST", list);
		request.getRequestDispatcher("../department_list.jsp").forward(request, response);
	}
	
	//添加部门信息
	public void toAdd(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
		//转发到department_add.jsp
		request.getRequestDispatcher("../department_add.jsp").forward(request, response);
	}
	//实际添加
	public void Add(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
		String name = request.getParameter("name");
		String address = request.getParameter("arrdess");
		
		Department department = new Department();
		department.setName(name);
		department.setName(address);
		
		departmentService.add(department);
		//转发
		response.sendRedirect("list.do");
	}
	
}