Web开发实训——学生信息管理系统（JSP+Servlet+Ajax+MySQL）

package servlet; import java.io.IOException; import java.io.PrintWriter; 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 com.alibaba.fastjson.JSONArray; import com.alibaba.fastjson.JSONObject; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; import dao.StudentSQL; import entity.Student; @WebServlet("/ShowServlet") public class ShowServlet extends HttpServlet { private static final long serialVersionUID = 1L; private StudentSQL studentSQL = new StudentSQL(); public ShowServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String control=null; control = request.getParameter("control"); String id = request.getParameter("id"); String name = request.getParameter("name"); String classes = request.getParameter("class"); String phone = request.getParameter("phone"); String mail = request.getParameter("mail"); float grade_web = Float.parseFloat(request.getParameter("grade_web")); float grade_learning = Float.parseFloat(request.getParameter("grade_learning")); Student student = new Student(id, name, classes, phone, mail, grade_web, grade_learning); if(control==null) return; if(control.equals("new")) studentSQL.insert(student); else if(control.equals("edit")) studentSQL.update(student); response.sendRedirect("index.jsp"); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String control=request.getParameter("control"); List<Student> list = new ArrayList<Student>();; if(control==null) { return; } else if(control.equals("show_all_student")) //显示全部 list=studentSQL.findall(); else if(control.equals("search")) { //数据库搜索 String key = request.getParameter("value"); List<String> columnList =studentSQL.getColumn(); //获取字段值 for(String column:columnList) { //遍历搜索 List<Student> array = new ArrayList<Student>(); array = studentSQL.find_condition(column,key); list.addAll(array); } Set<Student> set = new HashSet<Student>(list); //去重后set集合 List<Student> temp_list = new ArrayList<Student>(set); list=temp_list; } //删除记录 else if(control.equals("delete")){ String id = request.getParameter("value"); Student student = new Student(); student.setId(id); studentSQL.delete(student); list=studentSQL.findall(); } JSONArray jsonArray = new JSONArray(); for(Student student:list) { JSONObject json = new JSONObject(); json.put("id", student.getId()); json.put("name", student.getName()); json.put("classes", student.getClasses()); json.put("phone", student.getPhone()); json.put("mail",student.getMail()); json.put("grade_web", student.getGrade_web()); json.put("grade_learning", student.getGrade_learning()); jsonArray.add(json); } PrintWriter out = response.getWriter(); out.print(jsonArray); out.flush(); out.close(); } }