MVC模式的学生信息增删改查
准备：建一个名为 userdb的数据库。建一个student表,有stuid,stuname,gender三个字段。其中stuid为主键。j加入相应的驱动包，相应的JSTL标签
先看目录结构
代码：
DDUtil.java
package util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
/**
* @author sawyer 2014下午1:20:16
*
*/
public class DBUtil {
private Connection conn = null;
private PreparedStatement stmt = null;
private ResultSet rs = null;
private static String driver = "com.mysql.jdbc.Driver";
private String url = "jdbc:mysql://localhost:3306/userdb";
private String user = "root";
private String password = "orcl";
/**
* Get the driver
*/
static {
}
/**
* Connect the database
*/
public Connection getCon() {
try {
Class.forName(driver);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
try {
conn = (Connection) DriverManager
.getConnection(url, user, password);
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
/**
* @param sql
* @param obj
* Update
*//*
public int update(String sql, Object... obj) {
int count = 0;
conn = getCon();
try {
stmt = conn.prepareStatement(sql);
if (obj != null) {
for (int i = 0; i < obj.length; i++) {
stmt.setObject(i + 1, obj[i]);
}
}
count = stmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
} finally {
close();
}
return count;
}
*//**
* @param sql
* @param obj
* Query
*//*
public ResultSet Query(String sql, Object... obj) {
conn = getCon();
try {
stmt = conn.prepareStatement(sql);
while (obj != null) {
for (int i = 0; i < obj.length; i++) {
stmt.setObject(i + 1, obj[i]);
}
}
rs = stmt.executeQuery();
} catch (SQLException e) {
e.printStackTrace();
} finally {
close();
}
return rs;
}*/
/**
* CLose the resource
*/
public void close() {
try {
if (rs != null) {
rs.close();
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
if (stmt != null) {
stmt.close();
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
}
}
Student.java
package entity;
public class Student {
private int stuid;
private String stuname;
private String gender;
public int getStuid() {
return stuid;
}
public void setStuid(int stuid) {
this.stuid = stuid;
}
public String getStuname() {
return stuname;
}
public void setStuname(String stuname) {
this.stuname = stuname;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Student()
{
}
public Student(int stuid, String stuname, String gender) {
super();
stuid = this.stuid;
stuname = this.stuname;
gender = this.gender;
}
}
Model.java
package model;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import entity.Student;
import util.DBUtil;
public class Model {
private Statement sta;
private ResultSet rs;
PreparedStatement ps;
DBUtil u=new DBUtil();
public int Insert(int stuid,String stuname,String gender) throws SQLException{
Connection conn=u.getCon();
String sql="insert student values(?,?,?)";
ps=conn.prepareStatement(sql);
ps.setInt(1,stuid);
ps.setString(2,stuname);
ps.setString(3,gender);
int a=ps.executeUpdate();
return a;
}
public int delete(int stuid) throws SQLException{
Connection conn=u.getCon();
String sql="delete from student where stuid=?";
ps=conn.prepareStatement(sql);
ps.setInt(1,stuid);
int a=ps.executeUpdate();
return a;
}
public int update(int stuid,String stuname,String gender) throws SQLException{
Connection conn=u.getCon();
String sql="update student set stuname=?,gender=? where stuid=?";
ps=conn.prepareStatement(sql);
ps.setInt(3,stuid);
ps.setString(1,stuname);
ps.setString(2,gender);
int a=ps.executeUpdate();
return a;
}
public List<Student> queryAll() throws SQLException{
List<Student> students=new ArrayList<Student>();
Connection conn=u.getCon();
String sql="select * from student";
sta=conn.createStatement();
rs=sta.executeQuery(sql);
while(rs.next()){
Student student=new Student();
student.setStuid(rs.getInt("stuid"));
student.setStuname(rs.getString("stuname"));
student.setGender(rs.getString("gender"));
students.add(student);
}
return students;
}
public Student queryById(int stuid) throws SQLException{
Student student=new Student();
Connection conn=u.getCon();
String sql="select * from student where stuid=?";
ps=conn.prepareStatement(sql);
ps.setInt(1,stuid);
rs=ps.executeQuery();
if(rs.next()){
student.setStuid(rs.getInt("stuid"));
student.setStuname(rs.getString("stuname"));
student.setGender(rs.getString("gender"));
}
return student;
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> <display-name></display-name> <filter> <filter-name>EncodingFilter</filter-name> <filter-class>servlet.EncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>EncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <servlet> <servlet-name>QueryAll</servlet-name> <servlet-class>servlet.QueryAll</servlet-class> </servlet> <servlet-mapping> <servlet-name>QueryAll</servlet-name> <url-pattern>/QueryAll.do</url-pattern> </servlet-mapping> <servlet> <servlet-name>Insert</servlet-name> <servlet-class>servlet.Insert</servlet-class> </servlet> <servlet-mapping> <servlet-name>Insert</servlet-name> <url-pattern>/Insert.do</url-pattern> </servlet-mapping> <servlet> <servlet-name>SelectUpdate</servlet-name> <servlet-class>servlet.SelectUpdate</servlet-class> </servlet> <servlet-mapping> <servlet-name>SelectUpdate</servlet-name> <url-pattern>/SelectUpdate.do</url-pattern> </servlet-mapping> <servlet> <servlet-name>Update</servlet-name> <servlet-class>servlet.Update</servlet-class> </servlet> <servlet-mapping> <servlet-name>Update</servlet-name> <url-pattern>/Update.do</url-pattern> </servlet-mapping> <servlet> <servlet-name>Delete</servlet-name> <servlet-class>servlet.Delete</servlet-class> </servlet> <servlet-mapping> <servlet-name>Delete</servlet-name> <url-pattern>/Delete.do</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
QueryAll.java
package servlet;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import entity.Student;
import model.Model;
@SuppressWarnings("serial")
public class QueryAll extends HttpServlet{
public QueryAll(){
super();
}
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{
Model model=new Model();
try{
List<Student> list=model.queryAll();
request.getSession().setAttribute("list", list);
}catch(Exception e){
e.printStackTrace();
}
response.sendRedirect("index.jsp");
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException{
this.doGet(request, response);
}
}
Insert.java
package servlet;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import model.Model;
@SuppressWarnings("serial")
public class Insert extends HttpServlet{
public Insert(){
super();
}
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{
Model model = new Model();
int stuid = Integer.parseInt(request.getParameter("stuid"));
String stuname = request.getParameter("stuname");
String gender = request.getParameter("gender");
try {
model.Insert(stuid, stuname, gender);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
response.sendRedirect("QueryAll.do");
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException{
this.doGet(request, response);
}
}
Delete.java
package servlet;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import model.Model;
@SuppressWarnings("serial")
public class Delete extends HttpServlet{
public Delete(){
super();
}
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{
Model model=new Model();
int stuid=Integer.parseInt(request.getParameter("stuid"));
/*String stuname=request.getParameter("stuname");
String gender=request.getParameter("gender");*/
try {
model.delete(stuid);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
response.sendRedirect("QueryAll.do");
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException{
this.doGet(request, response);
}
}
SelectUpdate.java
package servlet;
import java.io.IOException;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import entity.Student;
import model.Model;
@SuppressWarnings("serial")
public class SelectUpdate extends HttpServlet{
public SelectUpdate(){
super();
}
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{
int stuid=Integer.parseInt(request.getParameter("stuid"));
Model model=new Model();
try {
Student student=model.queryById(stuid);
request.setAttribute("student", student);
int id=Integer.parseInt(request.getParameter("id"));
if(id==1){
request.getRequestDispatcher("update.jsp").forward(request, response);
}else if(id==2){
request.getRequestDispatcher("delete.jsp").forward(request, response);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ServletException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException{
this.doGet(request, response);
}
}
Update.java
package servlet;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import model.Model;
@SuppressWarnings("serial")
public class Update extends HttpServlet{
public Update(){
super();
}
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{
Model model=new Model();
int stuid=Integer.parseInt(request.getParameter("stuid"));
String stuname=request.getParameter("stuname");
String gender=request.getParameter("gender");
try {
model.update(stuid, stuname, gender);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
response.sendRedirect("QueryAll.do");
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException{
this.doGet(request, response);
}
}
EncodingFilter.java
package servlet;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class EncodingFilter implements Filter {
private String encoding = null;
public void init(FilterConfig config) throws ServletException {
this.encoding = config.getInitParameter("encoding");
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
request.setCharacterEncoding(this.encoding);
response.setCharacterEncoding(this.encoding);
chain.doFilter(request, response);
}
public void destroy() {
this.encoding = null;
}
}
index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@page language="java" import="model.*,entity.*,servlet.*"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <%@ taglib uri="http://jsptags.com/tags/navigation/pager" prefix="pg" %> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <h1>学生信息列表</h1> <a href="insert.jsp">新增</a><br><hr> <pg:pager maxPageItems="10" url="index.jsp"> <table border="1"> <tr><td>学号</td><td>姓名</td><td>性别</td><td>修改</td><td>删除</td></tr> <c:forEach items="${sessionScope.list}" var="student"> <pg:item> <tr> <td>${student.stuid}</td> <td>${student.stuname}</td> <td>${student.gender}</td> <td><a href="SelectUpdate.do?id=1&stuid=${student.stuid}">修改</a></td> <td><a href="SelectUpdate.do?id=2&stuid=${student.stuid}">删除</a></td> </tr> </pg:item> </c:forEach> <tr> <td> <pg:index> <pg:first><a href="${pageUrl}">第一页</a></pg:first> <pg:prev><a href="${pageUrl}">上一页</a></pg:prev> <pg:pages><a href="${pageUrl}">${pageNumber}</a></pg:pages> <pg:next><a href="${pageUrl}">下一页</a></pg:next> <pg:last><a href="${pageUrl}">最后一页</a></pg:last> </pg:index> </td> </tr> </table> </pg:pager> </body> </html>
delete.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'delete.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>删除数据</h1>
<form action="Delete.do" method="post">
<table>
<tr>
<td>请输入数据：</td>
<td>学号：<input type="text" name="stuid" id="stuid" value="${student.stuid}">
</td>
<td>姓名：<input type="text" name="stuname" id="stuname" value="${student.stuname}">
</td>
<td>性别：<input type="text" name="gender" id="gender" value="${student.gender}">
</td>
</tr>
<tr><td><input type="submit" value="删除"></td>
</table>
</form>
</body>
</html>
insert.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'insert.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>增加数据</h1>
<form action="Insert.do" method="post">
<table>
<tr>
<td>请插入数据：</td>
<td>学号：<input type="text" name="stuid" id="stuid">
</td>
<td>姓名：<input type="text" name="stuname" id="stuname">
</td>
<td>性别：<input type="text" name="gender" id="gender">
</td>
<td><input type="submit" value="插入" id="submit">
</td>
</tr>
</table>
</form>
</body>
</html>
update.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'update.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>更新数据</h1>
<form action="Update.do" method="post">
<table>
<tr>
<td>请输入数据：</td>
<td>学号：<input type="text" name="stuid" id="stuid" value="${student.stuid}">
</td>
<td>姓名：<input type="text" name="stuname" id="stuname" value="${student.stuname}">
</td>
<td>性别：<input type="text" name="gender" id="gender" value="${student.gender}">
</td>
</tr>
<tr><td><input type="submit" value="修改"></td>
<td><input type="reset" value="重置"></td></tr>
</table>
</form>
</body>
</html>
代码完美运行！！！