信息管理系统的增删改查

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 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;
}

}

2.

1)建接口类。

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);
}

2)接口类的实现

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;
}

}

3.建立每个接口方法的servlet。

1）添加的servlet

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);
}
}
}

2）删除的servlet。

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>

3）更新的servlet。

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);
}

}
}

4）查询的servlet。

以上即完成了增删改查的操作。

4. 建jsp页面。这是登录注册完成后跳转到的页面。有添加，删除，修改，查询的超链接，点击后跳转到相应页面可以进行相应的操作。

<%@ 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>