1，功能
1. 简单功能
1. 列表查询
2. 登录
3. 添加
4. 删除
5. 修改
2. 复杂功能
1. 删除选中
2. 分页查询
3. 复杂条件查询
2,所需jar包
mysql数据库
druid连接池
JDBCTemplate
jstl标签库
BeanUtils
3，功能实现
1,创建数据库
create database login; -- 创建数据库
use login; -- 使用数据库
create table user1( -- 创建表
id int primary key auto_increment,
name varchar(20) not null,
gender varchar(5),
age int,
address varchar(32),
qq varchar(20),
email varchar(50),
password varchar(32)
);
2,Druid连接池
create database login; -- 创建数据库
use login; -- 使用数据库
create table user1( -- 创建表
id int primary key auto_increment,
name varchar(20) not null,
gender varchar(5),
age int,
address varchar(32),
qq varchar(20),
email varchar(50),
password varchar(32)
);
2,Druid连接池
2.1，配置文件
driverClassName=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/login username=root password=wzl2001323 #初始化连接数量 initialSize=5 #最大连接数 maxActive=10 #最大等待时间 maxWait=3000
2.2, JDBC工具类
package util;
//jdbc工具类
import com.alibaba.druid.pool.DruidDataSourceFactory;
import javax.sql.DataSource;
import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
public class JDBCUtils {
//定义成员变量DataSource(连接池对象)
private static DataSource ds;
//在静态代码块中加载配置文件并获取连接池对象
static {
//1.加载配置文件
Properties pro= new Properties();
try {
pro.load(JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties"));
//2.获取Druid连接池对象
ds= DruidDataSourceFactory.createDataSource(pro);
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
//方法
//1.获取链接对象
public static Connection getConnection() throws SQLException {
return ds.getConnection();
}
//2.释放资源
//2.1没有使用ResultSet
public static void close(Statement stmt,Connection conn){
//调用该方法的重载方法关闭
close(null,stmt,conn);
}
public static void close(ResultSet rs,Statement stmt,Connection conn) {
if (rs != null) {
try {
rs.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
}
if(conn!=null) {
try {
conn.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
}
//3.获取连接池的方法
public static DataSource getDataSource(){
return ds;
}
}
3， web层
3,1jsp页面
1，list.jsp（用户信息展示页面）
<%--
Created by IntelliJ IDEA.
User: ASUS
Date: 2021/12/3
Time: 15:19
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>>
用户信息管理系统
td, th {
text-align: center;
}
用户信息列表
添加联系人
删除选中
2，add.jsp（添加用户的界面）
<%@page contentType="text/html;charset=UTF-8" language="java" %>
添加用户
添加联系人页面
3.update.jsp（修改用信息界面）
<%@page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
修改用户
修改联系人
4,login.jsp(用户登录界面)
<%--
Created by IntelliJ IDEA.
User: ASUS
Date: 2021/12/4
Time: 9:55
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
管理员登录
管理员登录
${requestScope.login_msg}
5index.jsp (登录后跳转的页面)
<%-- Created by IntelliJ IDEA. User: ASUS Date: 2021/12/2 Time: 17:10 To change this template use File | Settings | File Templates. --%> <%@ page contentType="text/html;charset=UTF-8" language="java" %>首页 ${sessionScope.user.name},欢迎您 查询所有用户信息
3,2, servlet
1，分页查询
代码：
package web.servlet;
import domain.PageBean;
import domain.User;
import service.UserService;
import service.impl.UserServiceImpl;
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;
import java.util.Map;
@WebServlet("/findUserByPageServlet")
public class FindUserByPageServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1,设置字符编码集
req.setCharacterEncoding("UTF-8");
//6实现复杂查询
//6.1获取请求条件参数
Map condition = req.getParameterMap();
//2,获取请求参数(rows和currentPage)
String rows = req.getParameter("rows");//每页显示的记录数
String currentPage = req.getParameter("currentPage");//当前页码
//3,调用service方法
UserService service=new UserServiceImpl();
PageBean pb=service.findUserByPage(currentPage,rows,condition);
//4,将PageBean存入request域,将条件存入request域
req.setAttribute("pb",pb);
req.setAttribute("condition",condition);
//5,转发到list.jsp
req.getRequestDispatcher("/list.jsp").forward(req,resp);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req,resp);
}
}
2.添加新用户
代码：
package web.servlet;
import domain.User;
import org.apache.commons.beanutils.BeanUtils;
import service.UserService;
import service.impl.UserServiceImpl;
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;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
@WebServlet("/addUserServlet")
public class AddUserServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1,设置编码
req.setCharacterEncoding("UTF-8");
//2,获取请求参数
Map map = req.getParameterMap();
//3,封装对象
User user=new User();
try {
BeanUtils.populate(user,map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
//4，调用Service保存
UserService service=new UserServiceImpl();
service.addUser(user);
//5,跳转到userListServlet
resp.sendRedirect(req.getContextPath()+"/findUserByPageServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req,resp);
}
}
3.删除
package web.servlet;
import service.UserService;
import service.impl.UserServiceImpl;
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("/deleteServlet")
public class DeleteServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.设置字符编码集
req.setCharacterEncoding("UTF-8");
//2，获取参数id
String id=req.getParameter("id");
//3，调用service方法删除
UserService service=new UserServiceImpl();
service.deleteUser(id);
//4，跳转到userListServlet
resp.sendRedirect(req.getContextPath()+"/findUserByPageServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req,resp);
}
}
4，删除选中
代码
package web.servlet;
import service.UserService;
import service.impl.UserServiceImpl;
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("/delSelectedServlet")
public class DelSelectedServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1,设置字符编码
req.setCharacterEncoding("UTF-8");
//2,获取所有id
String[] ids = req.getParameterValues("uid");
//3,调用service
UserService service=new UserServiceImpl();
service.delSelectedUser(ids);
//4,跳转页面
resp.sendRedirect(req.getContextPath()+"/findUserByPageServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req,resp);
}
}
5，登录
验证码
package web.servlet;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
//服务器通知浏览器不要缓存
response.setHeader("pragma","no-cache");
response.setHeader("cache-control","no-cache");
response.setHeader("expires","0");
//在内存中创建一个长80，宽30的图片，默认黑色背景
//参数一：长
//参数二：宽
//参数三：颜色
int width = 80;
int height = 30;
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
//获取画笔
Graphics g = image.getGraphics();
//设置画笔颜色为灰色
g.setColor(Color.GRAY);
//填充图片
g.fillRect(0,0, width,height);
//产生4个随机验证码，12Ey
String checkCode = getCheckCode();
//将验证码放入HttpSession中
request.getSession().setAttribute("CHECKCODE_SERVER",checkCode);
//设置画笔颜色为黄色
g.setColor(Color.YELLOW);
//设置字体的小大
g.setFont(new Font("黑体",Font.BOLD,24));
//向图片上写入验证码
g.drawString(checkCode,15,25);
//将内存中的图片输出到浏览器
//参数一：图片对象
//参数二：图片的格式，如PNG,JPG,GIF
//参数三：图片输出到哪里去
ImageIO.write(image,"PNG",response.getOutputStream());
}
private String getCheckCode() {
String base = "0123456789ABCDEFGabcdefg";
int size = base.length();
Random r = new Random();
StringBuffer sb = new StringBuffer();
for(int i=1;i<=4;i++){
//产生0到size-1的随机值
int index = r.nextInt(size);
//在base字符串中获取下标为index的字符
char c = base.charAt(index);
//将c放入到StringBuffer中去
sb.append(c);
}
return sb.toString();
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request,response);
}
}
登录
package web.servlet;
import domain.User;
import org.apache.commons.beanutils.BeanUtils;
import service.UserService;
import service.impl.UserServiceImpl;
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.lang.reflect.InvocationTargetException;
import java.util.Map;
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1,设置字符编码集
req.setCharacterEncoding("UTF-8");
//2，获取用户填写验证码，获取参数
String verifycode=req.getParameter("verifycode");
Map map = req.getParameterMap();
//3,判断验证码是否正确
HttpSession session=req.getSession();
String checkcode = (String)session.getAttribute("CHECKCODE_SERVER");
//删除验证码，防止复用
session.removeAttribute("CHECKCODE_SERVER");
if(!checkcode.equalsIgnoreCase(verifycode)){
//验证码不正确
//提示信息
req.setAttribute("login_msg","验证码错误");
//跳转页面
req.getRequestDispatcher("/login.jsp").forward(req,resp);
return;
}
//验证码正确
//4,封装User对象
User user=new User();
try {
BeanUtils.populate(user,map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
//5,调用service查询
UserService service=new UserServiceImpl();
User loginUser=service.login(user);
//6，判断是否登陆成功
if(loginUser!=null){
//登陆成功
//将用户存入session
session.setAttribute("user",loginUser);
//跳转页面
resp.sendRedirect(req.getContextPath()+"/index.jsp");
}
else{
//登录失败
req.setAttribute("login_msg","用户名或密码错误");
//跳转到登录页面
req.getRequestDispatcher("/login.jsp").forward(req,resp);
}
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req,resp);
}
}
6，修改信息
1，数据回显
package web.servlet;
import domain.User;
import service.UserService;
import service.impl.UserServiceImpl;
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("/findUserServlet")
public class FindUserServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1,设置字符编码集
req.setCharacterEncoding("UTF-8");
//2,获取请求参数id
String id=req.getParameter("id");
//3,调用service方法查询
UserService service=new UserServiceImpl();
User user=service.findUserById(id);
//4,转发到update.jsp
req.setAttribute("user",user);
req.getRequestDispatcher("/update.jsp").forward(req,resp);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req,resp);
}
}
2，修改
package web.servlet;
import domain.User;
import org.apache.commons.beanutils.BeanUtils;
import service.UserService;
import service.impl.UserServiceImpl;
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;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
@WebServlet("/updateUserServlet")
public class UpdateUserServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1,设置字符编码集
req.setCharacterEncoding("UTF-8");
//2，获取请求参数集合
Map map = req.getParameterMap();
//3,将参数封装成对象
User user=new User();
try {
BeanUtils.populate(user,map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
//4,调用Service修改
UserService service=new UserServiceImpl();
service.updateUser(user);
//5，跳转到uerListServlet
resp.sendRedirect(req.getContextPath()+"/findUserByPageServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req,resp);
}
}
4，service层 业务逻辑层
UserService接口
package service;
import domain.PageBean;
import domain.User;
import java.util.List;
import java.util.Map;
public interface UserService {
public List findAll();
public User login(User user);
public void addUser(User user);
public void deleteUser(String id);
public User findUserById(String id);
public void updateUser(User user);
public void delSelectedUser(String[] ids);
public PageBean findUserByPage(String _currentPage, String _rows, Map condition);
}
实现类
package service.impl;
import dao.UserDao;
import dao.impl.UserDaoImpl;
import domain.PageBean;
import domain.User;
import service.UserService;
import java.util.List;
import java.util.Map;
public class UserServiceImpl implements UserService {
private UserDao dao=new UserDaoImpl();
@Override
public List findAll() {
return dao.findAll();
}
@Override
public void addUser(User user) {
dao.add(user);
}
@Override
public User login(User user) {
return dao.findUserBynameAndPassword(user.getName(),user.getPassword());
}
@Override
public void deleteUser(String id) {
dao.delete(Integer.parseInt(id));
}
@Override
public User findUserById(String id) {
return dao.findById(Integer.parseInt(id));
}
@Override
public void updateUser(User user) {
dao.update(user);
}
@Override
public void delSelectedUser(String[] ids) {
if(ids!=null&&ids.length>0){
for (String id:ids) {
dao.delete(Integer.parseInt(id));
}
}
}
@Override
public PageBean findUserByPage(String _currentPage, String _rows, Map condition) {
//1，检查参数是否正确
if (_currentPage==null||"".equals(_currentPage)){
_currentPage="1";
}
if(_rows==null||"".equals(_rows)){
_rows="5";
}
//2,创建空的PageBean对象
PageBean pb=new PageBean();
int currentPage=Integer.parseInt(_currentPage);
int rows=Integer.parseInt(_rows);
//判断currentPage是否小于0
if(currentPage<=0){
currentPage=1;
}
//3,调用Dao方法查询
//3.1查询总记录数
int totalCount=dao.findTotalCount(condition);
//4.1计算总页码码数
int totalPage=totalCount%rows==0?totalCount/rows:totalCount/rows+1;
//判断currentPage是否大于最大页数
if(currentPage>totalPage){
currentPage=totalPage ;
}
//3.2查询用户信息
//计算开始的记录索引
int start=(currentPage-1)*rows;
if(start<0){
start=0;
}
List list=dao.findUserByPage(start,rows,condition);
//4，将数据封装到PageBean对象中
pb.setCurrentPage(currentPage);
pb.setList(list);
pb.setRows(rows);
pb.setTotalPage(totalPage);
pb.setTotalCount(totalCount);
return pb;
}
}
5，Dao层（持久层）
UserDao接口
package dao;
import domain.User;
import java.util.List;
import java.util.Map;
public interface UserDao {
public List findAll();
public User findUserBynameAndPassword(String name,String password);
public void add(User user);
public void delete(int id);
public User findById(int id);
public void update(User user);
public int findTotalCount(Map condition);
public List findUserByPage(int start, int rows, Map condition);
}
实现类
package dao.impl;
import dao.UserDao;
import domain.User;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import util.JDBCUtils;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class UserDaoImpl implements UserDao {
//创建连接池对象
private JdbcTemplate template= new JdbcTemplate(JDBCUtils.getDataSource());
@Override
public List findAll() {
//使用JDBC操作数据库
String sql="select * from user1";
List users = template.query(sql, new BeanPropertyRowMapper(User.class));
return users;
}
@Override
public User findUserBynameAndPassword(String name,String password){
//使用JDBC操作数据库
try {
String sql="select * from user1 where name= ? and password= ?";
User loginUser=template.queryForObject(sql,new BeanPropertyRowMapper(User.class),name,password);
return loginUser;
} catch (DataAccessException e) {
e.printStackTrace();
return null;
}
}
@Override
public void add(User user) {
String sql="insert into user1 values(null,?,?,?,?,?,?,null)";
template.update(sql,user.getName(),user.getGender(),user.getAge(),user.getAddress(),user.getQq(),user.getEmail());
}
@Override
public void delete(int id) {
String sql="delete from user1 where id=?";
template.update(sql,id);
}
@Override
public User findById(int id) {
try {
String sql="select * from user1 where id=?";
User user = template.queryForObject(sql, new BeanPropertyRowMapper(User.class), id);
return user;
} catch (DataAccessException e) {
e.printStackTrace();
return null;
}
}
@Override
public void update(User user) {
String sql="update user1 set name=?,gender=?,age=?,address=?,qq=?,email=? where id=?";
template.update(sql,user.getName(),user.getGender(),user.getAge(),user.getAddress(),user.getQq(),user.getEmail(),user.getId());
}
@Override
public int findTotalCount(Map condition) {
//1,定义模板初始化sql
String sql="select count(*) from user1 where 1=1";
StringBuilder sb=new StringBuilder(sql);
//2,遍历map集合取出查询条件
Set keySet = condition.keySet();
//创建list集合传参
List
6，javaBean对象
1，user对象
package domain;
public class User {
private int id;
private String name;
private String gender;
private int age;
private String address;
private String qq;
private String email;
private String password;
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
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 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;
}
public String getQq() {
return qq;
}
public void setQq(String qq) {
this.qq = qq;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + ''' +
", gender='" + gender + ''' +
", age=" + age +
", address='" + address + ''' +
", qq='" + qq + ''' +
", email='" + email + ''' +
'}';
}
}
2，page对象
package domain; import java.util.List; public class PageBean{ private int totalCount;//总记录数 private int rows;//每页显示的记录数 private int totalPage;//总页数 private int currentPage;//当前页数 private List list;//每页的数据 public int getTotalCount() { return totalCount; } public void setTotalCount(int totalCount) { this.totalCount = totalCount; } public int getRows() { return rows; } public void setRows(int rows) { this.rows = rows; } public int getTotalPage() { return totalPage; } public void setTotalPage(int totalPage) { this.totalPage = totalPage; } public int getCurrentPage() { return currentPage; } public void setCurrentPage(int currentPage) { this.currentPage = currentPage; } public List getList() { return list; } public void setList(List list) { this.list = list; } @Override public String toString() { return "PageBean{" + "totalCount=" + totalCount + ", rows=" + rows + ", totalPage=" + totalPage + ", currentPage=" + currentPage + ", list=" + list + '}'; } }
