\u003c%@ page contentType="text/html;charset=UTF-8" language="java"%3e\n\u003c%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%3e\n\u003chtml\u003e\n\u003chead\u003e\n\t\u003ctitle\u003e学生管理系统 - 添加/修改学生\u003c/title\u003e\n\u003c/head\u003e\n\u003cbody\u003e\n\n\u003cc:choose\u003e\n\t\u003cc:when test="${requestScope.tag=='add'}"\u003e\n\t

添加学生

\n\t\u003c/c:when\u003e\n\t\u003cc:when test="${requestScope.tag=='edit'}"\u003e\n\t

修改学生

\n\t\u003c/c:when\u003e\n\u003c/c:choose\u003e\n\n\n\u003cc:choose\u003e\n\u003cc:when test="${requestScope.tag=='add'}"\u003e\n\u003cform action="Studentcontroller.action?server=add" method="post"\u003e\n\t\u003c/c:when\u003e\n\t\u003cc:when test="${requestScope.tag=='edit'}"\u003e\n\t\u003cform action="Studentcontroller.action?server=edit" method="post"\u003e\n\t\u003c/c:when\u003e\n\t\u003c/c:choose\u003e\n\t\u003cdiv\u003e\n\t \u003clab\u003e名称：\u003c/lab\u003e\n\n\t \u003cc:choose\u003e\n\t \u003cc:when test="${requestScope.tag=='add'}"\u003e\n\t \u003cinput type="text" name="name"\u003e\n\t \u003c/c:when\u003e\n\t \u003cc:when test="${requestScope.tag=='edit'}"\u003e\n\t \u003cinput type="text" name="name" value="${requestScope.Student.name}"\u003e\n\t \u003cinput type="hidden" name="id" value="${requestScope.Student.id}"\u003e\n\t \u003cinput type="hidden" name="age" value="${requestScope.Student.age}"\u003e\n\t \u003cinput type="text" name="sex" value="${requestScope.Student.sex}"\u003e\n\t \u003cinput type="text" name="major" value="${requestScope.Student.major}"\u003e\n\t \u003cinput type="text" name="classname" value="${requestScope.Student.classname}"\u003e\n\t \u003c/c:when\u003e\n\t \u003c/c:choose\u003e\n\n\t\u003c/div\u003e\n\t\u003cdiv\u003e\n\t \u003cbutton type="submit"\u003e确定\u003c/button\u003e\n\t\u003c/div\u003e\n\n\u003c/form\u003e\n\u003c/body\u003e\n\u003c/html\u003e\n\npackage controller;\nimport bean.Student;\nimport services.Studentservlet;\nimport services.impl.Studentservletimpl;\nimport javax.servlet.ServletException;\nimport javax.servlet.http.HttpServlet;\nimport javax.servlet.http.HttpServletRequest;\nimport javax.servlet.http.HttpServletResponse;\nimport java.io.IOException;\nimport java.util.ArrayList;\n\npublic class Studentcontroller extends HttpServlet {\n\nStudentservlet ss=new Studentservletimpl();\n\tHttpServletRequest req;\n\tHttpServletResponse resp;\n\n\t@Override\n\tprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {\n\t req.setCharacterEncoding("utf-8");\n\t resp.setContentType("text/html;charset=UTF-8");\n\t this.req=req;\n\t this.resp=resp;\n\n\t String server=req.getParameter("server");\n\t if (server==null){\n\t req.setAttribute("mess","缺少服务参数");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp");\n\t return;\n\t }\n\n\t switch (server){\n\t case "GetAll":\n\t GetAll();\n\t break;\n\t case "add":\n\t add();\n\t break;\n\t case "del":\n\t delete();\n\t break;\n\t case "edit":\n\t edit();\n\t break;\n\t case "editView":\n\t editView();\n\t break;\n\t case "addView":\n\t addView();\n\t break;\n\t default:\n\t req.setAttribute("mess", "你给出无效服务参数值");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\t}\n\t@Override\n\tprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {\n\t doGet(req, resp);\n\t}\n\tprivate void GetAll() throws ServletException, IOException {\n\t ArrayList\u003cStudent\u003e all = ss.GetAll();\n\t req.setAttribute("stu", all);\n\t req.getRequestDispatcher("/WEB-INF/studentview.jsp").forward(req, resp);\n\t}\n\n\tprivate void add() throws ServletException, IOException {\n\t String name = req.getParameter("name");\n\t if (name == null) {\n\t req.setAttribute("mess", "没有名称");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\n\t Student STU = new Student();\n\t STU.setName(name);\n\t Boolean add = ss.add(STU);\n\t if (!add) {\n\t req.setAttribute("mess", "添加失败");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\t resp.sendRedirect("/Studentcontroller.action?server=GetAll");\n\t}\n\n\tprivate void delete() throws ServletException, IOException {\n\t String id = req.getParameter("id");\n\t if (id == null) {\n\t req.setAttribute("mess", "ID不能为空");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\t int idTemp = 0;\n\t try {\n\n\t idTemp = Integer.parseInt(id);\n\t } catch (NumberFormatException e) {\n\t req.setAttribute("mess", "ID值必为整数");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\n\t Boolean delete = ss.delete(idTemp);\n\t if (!delete) {\n\t req.setAttribute("mess", "删除错误");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\n\t resp.sendRedirect("/Studentcontroller.action?server=GetAll");\n\n\t}\n\n\tprivate void edit() throws ServletException, IOException {\n\t String id = req.getParameter("id");\n\t if (id == null) {\n\t req.setAttribute("mess", "ID不能为空");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\t int idTemp = 0;\n\t try {\n\n\t idTemp = Integer.parseInt(id);\n\t } catch (NumberFormatException e) {\n\t req.setAttribute("mess", "ID值必须为整数");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\n\t String name = req.getParameter("name");\n\t if (name == null) {\n\t req.setAttribute("mess", "没有名称参数");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\n\t Student stu = new Student();\n\t stu.setId(idTemp);\n\t stu.setName(name);\n\t Boolean edit =ss.edit(stu);\n\t if (!edit) {\n\t req.setAttribute("mess", "修改失败");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\t resp.sendRedirect("/Studentcontroller.action?server=GetAll");\n\t}\n\n\tprivate void editView() throws ServletException, IOException {\n\t String id = req.getParameter("id");\n\t if (id == null) {\n\t req.setAttribute("mess", "ID不能为空");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\t int idTemp = 0;\n\t try {\n\t idTemp = Integer.parseInt(id);\n\t } catch (NumberFormatException e) {\n\t req.setAttribute("mess", "ID值必为整数");\n\t req.getRequestDispatcher("/WEB-INF/error.jsp").forward(req, resp);\n\t return;\n\t }\n\n\t Student stu = ss.get(idTemp);\n\t req.setAttribute("stu", stu);\n\t req.setAttribute("tag", "edit");\n\t req.getRequestDispatcher("/WEB-INF/studentsave.jsp").forward(req, resp);\n\t}\n\n\tprivate void addView() throws ServletException, IOException {\n\t req.setAttribute("tag", "add");\n\t req.getRequestDispatcher("/WEB-INF/studentsave.jsp").forward(req, resp);\n\t}\n}\n\n为什么无法解析/Studentcontroller.action