500出错了?
来源:3-3 综合训练-实现新增员工功能
Ctrlzhao
2019-11-20 23:12:49
package com.imooc.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 CreateServlet */ @WebServlet("/create") public class CreateServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public CreateServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); String empno=request.getParameter("empno"); String ename=request.getParameter("enaem"); String department=request.getParameter("department"); String job=request.getParameter("job"); String salary=request.getParameter("salary"); System.out.println(empno); Employee emp=new Employee(Integer.parseInt(empno),ename,department,job,Float.parseFloat(salary)); ServletContext context=request.getServletContext(); List employees=(List)context.getAttribute("employees"); employees.add(emp); context.setAttribute("employees", employees); request.getRequestDispatcher("/employee.jsp").forward(request, response); } }
1回答
同学你好,根据报错信息,代码第44行报出NullPointerException异常-->空指针异常,说明employees是null。
这里测试贴出的CreateServlet在老师的代码中,并没有报出控制针异常的错误,所以同学可以检查自己的ListServlet中,employees单词是否书写正确,导致CreateServlet没有获取到employees的对应内容,例如:
如果我的回答解决了你的疑惑,请采纳。祝:学习愉快~
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