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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