麻烦看下我这段代码哪里出错了吗，新增员工会出现服务器内部错误

package com.xiaocai.employee;

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

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class EmployeeServlet
 */
@WebServlet("/EmployeeServlet")
public class EmployeeServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public EmployeeServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doPost(request, response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//设置编码方式
		request.setCharacterEncoding("utf-8");
		
		//获取客户端请求的参数值
		String empon=(String)request.getAttribute("empno");
		String ename=(String)request.getAttribute("ename");
		String department=(String)request.getAttribute("department");
		String job=(String)request.getAttribute("job");
		String salary=(String)request.getAttribute("salary");
		
		Employees emp=new Employees(Integer.parseInt(empon),ename,department,job,Float.parseFloat(salary));
		
		
		ServletContext context=request.getServletContext();
		List employees=(List)context.getAttribute("employees");
		
		//将请求的参数保存到集合当中
		employees.add(emp);
		
	    context.setAttribute("employees", employees);
	    
		//请求转发到下一个页面
		request.getRequestDispatcher("/employee.jsp").forward(request, response);
	}

}