简单的javaweb在线选课系统（idea使用，版本原因，需要修改些许代码去适应个人的idea配置）

package online_select.Student; import online_select.Login.Power; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.util.List; @WebServlet("/SelectServlet") public class SelectServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public SelectServlet() { super(); // TODO Auto-generated constructor stub } protected void service(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException { arg0.setCharacterEncoding("utf-8"); arg1.setCharacterEncoding("utf-8"); boolean flag; String function=arg0.getParameter("method"); if(function.equals("submit")) { List<CourseService> userall = StudentGet.getAll(); java.util.Collections.reverse(userall); arg0.setAttribute("all", userall); arg0.getRequestDispatcher("student/Select.jsp").forward(arg0, arg1); } if(function.equals("select")) { Change c=new Change(); CourseDao j=new CourseDao(); StudentFind f=new StudentFind(); f.find("student", Power.getName()); String teac_name; teac_name = arg0.getParameter("teac_name"); j.setTeac_name(teac_name); String course_id; course_id=arg0.getParameter("course_id"); j.setCourse_id(course_id); String existing; existing=arg0.getParameter("existing"); String teac_id; teac_id=arg0.getParameter("teac_id"); j.setTeac_id(teac_id); j.setStu_name(StudentService.getStu_name()); j.setStu_id(StudentService.getStu_id()); int num=Integer.parseInt(existing); num++; System.out.println(num); StudentSelect s=new StudentSelect(); flag=s.select("course",course_id, StudentService.getStu_id()); if(flag) { c.change("class", "existing", "course_id", num+"", course_id); StudentAdd a=new StudentAdd(); a.add("course", j); arg0.setAttribute("message", "选课成功"); arg0.getRequestDispatcher("Right.jsp").forward(arg0, arg1); } else { arg0.setAttribute("message", "选课重复"); arg0.getRequestDispatcher("Right.jsp").forward(arg0, arg1); } } } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.getWriter().append("Served at: ").append(request.getContextPath()); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } }