使用idea开发javaWeb应用程序的思路(实现用户的增删改查)
如沐春风细雨中 人气:0这篇文章主要介绍了使用idea开发javaWeb应用程序的思路(实现用户的增删改查),本文给大家介绍的非常详细，对大家的学习或工作具有一定的参考借鉴价值，需要的朋友可以参考下
在2.7 节基础上，这一节实现了用户的增删改查操作。
完整工程代码：
链接: http://pan.baidu.com/s/1zSGMvSQa-ihwEN5pP4vW6w 提取码: dpw8
工程目录结构如下：
1、添加/修改用户页面
在webapp下新建目录user，用于存放用户相关的页面。
添加和修改使用的是同一个页面，通过url中的参数控制是否是修改操作。
后台通过是否传递了id进行判断新增还是修改。
新建：add.html，代码如下：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>登录页面</title>
<link rel="stylesheet" type="text/css" href="../css/my.css" rel="external nofollow" rel="external nofollow" >
<script type="text/javascript" src="../js/my.js"></script>
</head>
<body>
<div id="main-container" >
<div id="div-header" >
<h3 style="margin-bottom:0;">欢迎进入我的网站</h3>
</hr>
<p>
天将降大任于斯人也，必先苦其心志，劳其筋骨，饿其体肤，空乏其身，行拂乱其所为，所以动心忍性，曾益其所不能。——孟子
</p>
</div>
<div id="div-content" >
<h3 style="margin-bottom:0;">添加用户</h3>
<form id="userAddForm" class="userAddForm" action="addUser" method="post">
<input id="id" type="hidden" name="id" />
<p>登录账号: <input id="uname" type="text" name="uname" /></p>
<p>真实姓名: <input id="realName" type="text" name="realName" /></p>
<p>选择性别: <select id="sex" name="sex" style="width:170px">
<option id="option_m" value ="男">男</option>
<option id="option_w" value ="女">女</option>
</select></p>
<p>登录密码: <input id="pwd" type="password" name="pwd" /></p>
<p>确认密码: <input id="pwdRepeat" type="password" name="pwdRepeat" /></p>
<input type="button" value="提交" onclick="submitAddUser()"/>
</form>
</div>
</div>
<script type="text/javascript">
//检查输入是否为非空
function submitAddUser()
{
var uname = document.getElementById("uname").value;//获取输入的用户名的值
var pwd = document.getElementById("pwd").value;//获取输入的密码值
var pwdRepeat = document.getElementById("pwdRepeat").value;//获取输入确认密码值
var realName = document.getElementById("realName").value;//获取输入的姓名值
var sex = document.getElementById("sex").value;//获取输入的性别值
if(uname == "" || pwd == "" || pwdRepeat == "" || realName == "" || sex == "" ){
alert("请将信息填写完整后再提交。");
return;
}
if( pwd != pwdRepeat){
alert("两次密码输入不一致，请重新输入。");
}
document.getElementById("userAddForm").submit(); //输入不为空则跳转到主页面
}
//从url中获取参数
function getQueryVariable(variable)
{
var query = window.location.search.substring(1);
console.log(query);
var vars = query.split("&");
for (var i=0;i<vars.length;i++) {
var pair = vars[i].split("=");
if(pair[0] == variable){return decodeURI(pair[1]);}
}
return(false);
}
//判断参数是否为true，不为true则弹窗提示密码错误。
var bool = getQueryVariable("success");
var operation = getQueryVariable("operation");
if(bool == "false" && operation=="addUser"){
alert("操作失败。");
}else if(bool == "true" && operation=="addUser"){
alert("操作成功。");
}
showOld();
//从url中获取参数，回显
function showOld()
{
var uname = getQueryVariable("uname");
var realName = getQueryVariable("realName");
var id = getQueryVariable("id");
var sex = getQueryVariable("sex");
var pwd = getQueryVariable("pwd");
if(id != "" && id != null){
document.getElementById("uname").value=uname;
document.getElementById("pwd").value=pwd;
document.getElementById("pwdRepeat").value = pwd;
document.getElementById("realName").value = realName;
document.getElementById("id").value = id;
if(sex == "男"){
document.getElementById("option_m").selected = true;
}else{
document.getElementById("option_w").selected = true;
}
}
}
</script>
</body>
</html>
2、查询用户页面
在user目录下新建list.jsp，代码如下：
<%@page import="java.util.ArrayList"%>
<%@page import="com.my.site.UserEntity"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<title>我的网站</title>
<meta charset="utf-8">
<link rel="stylesheet" type="text/css" href="../css/my.css" rel="external nofollow" rel="external nofollow" >
</head>
<body>
<!-- jsp 页面可以内嵌 java代码-->
<%
ArrayList<UserEntity> all = ( ArrayList<UserEntity>)session.getAttribute("all");
%>
<div id="main-container" >
<div id="div-header" >
<h3 style="margin-bottom:0;">用户查询</h3>
</hr>
<p>
天将降大任于斯人也，必先苦其心志，劳其筋骨，饿其体肤，空乏其身，行拂乱其所为，所以动心忍性，曾益其所不能。——孟子
</p>
</div>
<div id="div-content" >
<table border="1" class="table" >
<tr>
<td>编号</td>
<td>用户名</td>
<td>密码</td>
<td>真实姓名</td>
<td>性别</td>
<td>注册时间</td>
<td>操作</td>
</tr>
<%
for(UserEntity user:all)
{%>
<tr>
<td ><%=user.getId() %></td>
<td><%=user.getUname() %></td>
<td><%=user.getPwd() %></td>
<td><%= user.getRealName() %></td>
<td><%= user.getSex() %></td>
<td><%= user.getAdd_time() %></td>
<td><a href="del?id=<%=user.getId()%> " rel="external nofollow" >删除</a>
<a href="add.html?id=<%=user.getId()%>&uname=<%=user.getUname()%>&pwd=<%=user.getPwd()%>&realName=<%=user.getRealName()%>&sex=<%=user.getSex()%>" rel="external nofollow" >修改</a>
</td>
</tr>
<%}
%>
</table>
<p>
当前时间: <%= (new java.util.Date()).toLocaleString()%>
</p>
</div>
</div>
<script type="text/javascript">
//点击按钮跳转到登录页面
function toAddUser()
{
window.location.href="user/add.html" rel="external nofollow" ;
}
function toSearchUser()
{
window.location.href="user/list" rel="external nofollow" ;
}
</script>
</body>
</html>
3、编写后台逻辑-添加/修改
新建：UserAdd类
package com.my.site;
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;
@WebServlet("/user/addUser")
public class UserAdd extends HttpServlet {
/** req 携带了请求相关信息，包括各种配置和请求参数； resp：携带返回相关信息 */
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//从请求对象中获取请求参数：是从前端 usr/add.html页面的 userAddForm 表单提交过来的
String uname = new String(req.getParameter("uname").getBytes("ISO-8859-1"),"utf-8");
String pwd = new String(req.getParameter("pwd").getBytes("ISO-8859-1"),"utf-8");
String realName = new String(req.getParameter("realName").getBytes("ISO-8859-1"),"utf-8");
String sex = new String(req.getParameter("sex").getBytes("ISO-8859-1"),"utf-8");
String pwdRepeat = new String(req.getParameter("pwdRepeat").getBytes("ISO-8859-1"),"utf-8");
String id_str = req.getParameter("id");
boolean bool = false;
//如果有id，就执行更新操作，没有id则执行新增操作
if(null != id_str && !"".equals(id_str)){
int id = Integer.parseInt(req.getParameter("id"));
bool = MySqlOperator.updateUser(id,uname, pwd, realName, sex);
}else {
bool = MySqlOperator.addUser(uname, pwd, realName, sex);
}
resp.setContentType("text/html;charset=UTF-8");
if(bool){
//跳转到主页面，并携带请求体，返回体对象。
resp.sendRedirect("add.html?operation=addUser&success=true");
}else{
//校验失败则跳转到登录页面
resp.sendRedirect("add.html?operation=addUser&success=false");
}
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
}
4、编写后台逻辑-查询
新建 UserList 类
package com.my.site;
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 javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.List;
@WebServlet("/user/list")
public class UserList extends HttpServlet {
/** req 携带了请求相关信息，包括各种配置和请求参数； resp：携带返回相关信息 */
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
List<UserEntity> all = MySqlOperator.listAllUser();
HttpSession session = req.getSession();
session.setAttribute("all",all);
resp.setContentType("text/html;charset=UTF-8");
resp.sendRedirect("list.jsp");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
}
5、编写后台逻辑-删除
新建UserDel
package com.my.site;
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;
@WebServlet("/user/del")
public class UserDel extends HttpServlet {
/** req 携带了请求相关信息，包括各种配置和请求参数； resp：携带返回相关信息 */
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//从请求对象中获取请求参数：是从前端 usr/add.html页面的 userAddForm 表单提交过来的
int id = Integer.parseInt(req.getParameter("id").trim());
MySqlOperator.delUser(id);
resp.setContentType("text/html;charset=UTF-8");
resp.sendRedirect("list");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
}
6、 编写数据库操作
package com.my.site;
import java.sql.*;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class MySqlOperator {
private static final String MYSQL_URL = "jdbc:mysql://localhost:3309/ztest?allowPublicKeyRetrieval=true&useSSL=false&serverTimezone=UTC";
private static final String MYSQL_NAME = "root";
private static final String MYSQL_PASSWORD = "MySql@8022";
private static Connection conn = null;
private static Statement stt = null;
static {
try {
Class.forName("com.mysql.cj.jdbc.Driver");
conn = DriverManager.getConnection(MYSQL_URL,MYSQL_NAME,MYSQL_PASSWORD);
stt = conn.createStatement();
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
}
/**
* 根据用户名和密码检查是否合法用户，
* @param uname
* @param pwd
* @return
*/
public static boolean loginChecked(String uname,String pwd){
try {
Statement stt = conn.createStatement();
String sql = "select * from user where account='"+uname+"' and password = '"+pwd+"'";//这样写是有sql注入漏洞的，后面会用到
System.out.println(sql);
ResultSet rs = stt.executeQuery(sql);
while (rs.next()){
return true;
}
} catch ( SQLException e) {
e.printStackTrace();
}
return false;
}
/**
* 添加用户
*/
public static boolean addUser(String uname,String pwd,String realName,String sex){
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:sss");
String data_str = sdf.format(date);
String sql = "insert into user(account,name,password,sex,add_time) values" +
" ('"+uname+"','"+realName+"','"+pwd+"','"+sex+"','"+data_str+"')";
System.out.println(sql);
try {
if(conn.isValid(2)){
initConn();
}
stt.execute(sql);
return true;
} catch (SQLException throwable) {
throwable.printStackTrace();
return false;
}
}
/**查询所有用户*/
public static List<UserEntity> listAllUser(){
String sql = "select * from user";
ResultSet rs = null;
ArrayList<UserEntity> all = new ArrayList<>();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:sss");
try {
rs = stt.executeQuery(sql);
while (rs.next()){
UserEntity user = new UserEntity();
user.setUname(rs.getString("account"));
user.setPwd(rs.getString("password"));
user.setRealName(rs.getString("name"));
user.setSex(rs.getString("sex"));
user.setAdd_time(sdf.format(rs.getDate("add_time")));
user.setId(rs.getInt("id"));
all.add(user);
}
System.out.println(sql);
System.out.println("查询条数："+all.size());
return all;
} catch (SQLException throwable) {
throwable.printStackTrace();
}
return all;
}
/**删除用户*/
public static boolean delUser(int id) {
String sql = "delete from user where id="+id;
try {
stt.execute(sql);
return true;
} catch (SQLException throwable) {
throwable.printStackTrace();
return false;
}
}
/**用于 mysql 连接断开后重连*/
public static void initConn(){
try {
Class.forName("com.mysql.cj.jdbc.Driver");
conn = DriverManager.getConnection(MYSQL_URL,MYSQL_NAME,MYSQL_PASSWORD);
stt = conn.createStatement();
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
}
/**更新用户信息*/
public static boolean updateUser(int id, String uname, String pwd, String realName, String sex) {
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:sss");
String data_str = sdf.format(date);
String sql = "update user set account='"+uname+"',password='"+pwd+"',name='"+realName+"',sex='"+sex+"',add_time='"+data_str+"' where id="+id;
System.out.println(sql);
try {
if(conn.isValid(2)){
initConn();
}
stt.execute(sql);
return true;
} catch (SQLException throwable) {
throwable.printStackTrace();
return false;
}
}
}
7、 运行效果
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