代码在修改更新上有一些缺陷,应该先把相应的要修改的部分查询显示显示出来再进行修改。其实完成增删改查的原理与登录注册是一样的。 1.首先建student类。 public class Studentmodel {private int id;private String name;private String grade;private Str
public class Studentmodel { private int id; private String name; private String grade; private String gender; private int age; private String address; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getGrade() { return grade; } public void setGrade(String grade) { this.grade = grade; } public String getGender() { return gender; } public void setGender(String gender) { this.gender = gender; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } }
package cn.edu.hpu.service; import cn.edu.hpu.model.Studentmodel; public interface Student { public boolean addStu(Studentmodel studentmodel); public boolean delStu(int id); public boolean updStu(int id,Studentmodel studentmodel); public Studentmodel selStu(int id); }
package cn.edu.hpu.service; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import com.mysql.jdbc.Connection; import cn.edu.hpu.model.Studentmodel; import cn.edu.hpu.util.Util; public class StudentImpl implements Student { @Override public boolean addStu(Studentmodel studentmodel) { boolean flag=false; String sql="insert into student1(id,name,grade,gender,age,address) value(?,?,?,?,?,?)"; Connection conn=Util.getConnection(); PreparedStatement pst; try { pst = conn.prepareStatement(sql); pst.setInt(1, studentmodel.getId()); pst.setString(2, studentmodel.getName()); pst.setString(3, studentmodel.getGrade()); pst.setString(4, studentmodel.getGender()); pst.setInt(5, studentmodel.getAge()); pst.setString(6, studentmodel.getAddress()); pst.executeUpdate(); flag=true; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return flag; } @Override public boolean delStu(int id) { boolean flag=false; String sql="delete from student1 where id="+id; Connection conn=Util.getConnection(); try { PreparedStatement pst=conn.prepareStatement(sql); pst.executeUpdate(); flag=true; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return flag; } @Override public boolean updStu(int id, Studentmodel studentmodel) { boolean flag=false; String sql="update student1 set id=?,name=?,grade=?,gender=?,age=?,address=? where id="+id; Connection conn=Util.getConnection(); PreparedStatement pst; try { pst = conn.prepareStatement(sql); pst.setInt(1, studentmodel.getId()); pst.setString(2, studentmodel.getName()); pst.setString(3,studentmodel.getGrade()); pst.setString(4, studentmodel.getGender()); pst.setInt(5, studentmodel.getAge()); pst.setString(6, studentmodel.getAddress()); pst.executeUpdate(); flag=true; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return flag; } @Override public Studentmodel selStu(int id) { Studentmodel studentmodel=new Studentmodel(); String sql="select * from student1 where id=?"; Connection conn=Util.getConnection(); try { PreparedStatement pst=conn.prepareStatement(sql); pst.setInt(1,id); ResultSet rs=pst.executeQuery(); while(rs.next()){ //遍历结果集 studentmodel.setId(rs.getInt("id")); studentmodel.setName(rs.getString("name")); studentmodel.setGrade(rs.getString("grade")); studentmodel.setGender(rs.getString("gender")); studentmodel.setAge(rs.getInt("age")); studentmodel.setAddress(rs.getString("address")); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } // TODO Auto-generated method stub return studentmodel; } }
package cn.edu.hpu.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import cn.edu.hpu.model.Studentmodel; import cn.edu.hpu.service.Student; import cn.edu.hpu.service.StudentImpl; public class tianjia extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); int Id = Integer.parseInt(request.getParameter("id")); String Name=request.getParameter("name"); String Grade=request.getParameter("grade"); String Gender=request.getParameter("gender"); int Age=Integer.parseInt(request.getParameter("age")); String Address=request.getParameter("address"); Studentmodel studentmodel=new Studentmodel(); studentmodel.setId(Id); studentmodel.setName(Name); studentmodel.setGrade(Grade); studentmodel.setGender(Gender); studentmodel.setAge(Age); studentmodel.setAddress(Address); Student stu=new StudentImpl(); boolean flag=stu.addStu(studentmodel); if(flag){ StudentDaoServlet s=new StudentDaoServlet(); s.doPost(request, response); } } }
package cn.edu.hpu.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import cn.edu.hpu.model.Studentmodel; import cn.edu.hpu.service.Student; import cn.edu.hpu.service.StudentImpl; public class shanchu extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); int Id=Integer.parseInt(request.getParameter("id")); Studentmodel studentmodel=new Studentmodel(); studentmodel.setId(Id); Student stu=new StudentImpl(); boolean flag=stu.delStu(Id); if(flag){ StudentDaoServlet s=new StudentDaoServlet(); s.doPost(request, response); }<span style="font-family:KaiTi_GB2312;"> } }</span>
package cn.edu.hpu.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import cn.edu.hpu.model.Studentmodel; import cn.edu.hpu.service.Student; import cn.edu.hpu.service.StudentImpl; public class gengxin extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); int Id=Integer.parseInt(request.getParameter("id")); String Name=request.getParameter("name"); String Grade=request.getParameter("grade"); String Gender=request.getParameter("gender"); int Age=Integer.parseInt(request.getParameter("age")); String Address=request.getParameter("address"); Studentmodel studentmodel=new Studentmodel(); studentmodel.setId(Id); studentmodel.setName(Name); studentmodel.setGrade(Grade); studentmodel.setGender(Gender); studentmodel.setAge(Age); studentmodel.setAddress(Address); Student stu=new StudentImpl(); boolean flag=stu.updStu(Id, studentmodel); if(flag){ StudentDaoServlet s=new StudentDaoServlet(); s.doPost(request, response); } } }
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head>可以 <title>My JSP 'success.jsp' starting page</title> <style type="text/css"> .body{background-image:url("1.jpg");width: 1200px;height: 600px;margin-left: 30px;margin-top:10px} .hh{padding-top:0.05px;text-align: center;} .a{width:1200;heigh:500px;} .b{float:left;width:100px;height:500px;} .c{float:right;width:1100px;height:500px;} input{ border-radius:30px;border-color:coral;height:30px;} </style> </head> <body> <div class="body"> <h1 style="font-family:华文楷体;color:purple;" >欢迎你!<%=session.getAttribute("username") %></h1> <div class="hh"> <center style="font-family:华文楷体"><h1>欢迎登陆教务处系统</h1></center></div> <div class="a"> <div class="b"> <a href="tianjia.jsp"><h1 style="font-family:华文楷体">添加</h1></a><br> <a href="shanchu.jsp"><h2 style="font-family:华文楷体">删除</h2></a><br> <a href="gengxin.jsp"><h2 style="font-family:华文楷体">更新</h2></a><br> <a href="chazhao.jsp"><h1 style="font-family:华文楷体">查找</h1></a> </div> <div class="c"> <center> <br> <table border="3" align="center" width=850px; height=350px;> <tr> <td>ID:</td> <td>Name:</td> <td>Grade:</td> <td>Gender:</td> <td>Age:</td> <td>Address:</td> </tr> <c:forEach items="${pb.beanlist }" var="studentmodel"> <tr> <td>${studentmodel.id }</td> <td>${studentmodel.name }</td> <td>${studentmodel.grade }</td> <td>${studentmodel.gender}</td> <td>${studentmodel.age}</td> <td>${studentmodel.address}</td> </tr> </c:forEach> </table><br><br> <%@include file="/Page.jsp" %> </center> </div> </div> </div> </body> </html>
至此完成了增删改查的相应操作。