简单的增删改查及数据分页
简单的增删改查及数据分页
- 一、结构图
- 二、相关代码
-
-
- ① User类
- ② Page类
- ③ UserDao类
- ④ CodeFilter类
- ⑤ UserService 类
- ⑥ IndexServlet 类
- ⑦ UserDeleteServlet 类
- ⑧ UserEditServlet 类
- ⑨ edit.jsp
- ⑩ index.jsp
- ⑩① web.xml
- ⑩② pom.xml
-
- 三、效果截图
一、结构图
二、相关代码
① User类
package com.allen.entity;
import java.util.Date;
public class User {
private Integer id;
private String trueName;
private String loginName;
private String loginPassword;
private Integer role;
private Date createTime;
private Date updateTime;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getTrueName() {
return trueName;
}
public void setTrueName(String trueName) {
this.trueName = trueName;
}
public String getLoginName() {
return loginName;
}
public void setLoginName(String loginName) {
this.loginName = loginName;
}
public String getLoginPassword() {
return loginPassword;
}
public void setLoginPassword(String loginPassword) {
this.loginPassword = loginPassword;
}
public Integer getRole() {
return role;
}
public void setRole(Integer role) {
this.role = role;
}
public Date getCreateTime() {
return createTime;
}
public void setCreateTime(Date createTime) {
this.createTime = createTime;
}
public Date getUpdateTime() {
return updateTime;
}
public void setUpdateTime(Date updateTime) {
this.updateTime = updateTime;
}
}
② Page类
package com.allen.entity.ao;
import java.util.List;
public class Page<T> {
private List<T> list;
private long count;
private int pageCount;
private int page=1;
private int size=10;
public List<T> getList() {
return list;
}
public void setList(List<T> list) {
this.list = list;
}
public long getCount() {
return count;
}
public void setCount(long count) {
this.count = count;
}
public int getPageCount() {
return pageCount;
}
public void setPageCount(int pageCount) {
this.pageCount = pageCount;
}
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public int getSize() {
return size;
}
public void setSize(int size) {
this.size = size;
}
}
③ UserDao类
package com.allen.dao;
import com.allen.entity.User;
import java.sql.*;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class UserDao {
/**
* 分页查询数据，模糊查询名字的数据
*
* @param page
* @param size
* @param name
* @return
* @throws ClassNotFoundException
* @throws SQLException
*/
public List<User> find(int page, int size, String name) throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///user-test?useSSL=false", "root", "123456");
PreparedStatement statement;
if (name != null && name != "") {
statement = connection.prepareStatement("select * from user where true_name like ? limit ?,?");
statement.setObject(1, "%" + name + "%");
statement.setObject(2, (page - 1) * size);
statement.setObject(3, size);
} else {
statement = connection.prepareStatement("select * from user limit ?,?");
statement.setObject(1, (page - 1) * size);
statement.setObject(2, size);
}
ResultSet resultSet = statement.executeQuery();
List<User> list = new ArrayList<>();
while (resultSet.next()) {
User user = new User();
user.setId(resultSet.getInt("id"));
user.setTrueName(resultSet.getString("true_name"));
user.setLoginName(resultSet.getString("login_name"));
user.setLoginPassword(resultSet.getString("login_password"));
user.setRole(resultSet.getInt("role"));
//这里需要使用时间戳，才会显示年月日，时分秒
user.setCreateTime(resultSet.getTimestamp("create_time"));
user.setUpdateTime(resultSet.getTimestamp("update_time"));
list.add(user);
}
resultSet.close();
statement.close();
connection.close();
return list;
}
/**
* 查询特定名字的人数或全部数据的数量
*
* @param name
* @return
* @throws ClassNotFoundException
* @throws SQLException
*/
public long count(String name) throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///user-test?useSSL=false", "root", "123456");
PreparedStatement statement;
if (name != null && name != "") {
statement = connection.prepareStatement("select count(*) from user where true_name like ?");
statement.setObject(1, "%" + name + "%");
} else {
statement = connection.prepareStatement("select count(*) from user");
}
ResultSet resultSet = statement.executeQuery();
long count = 0;
while (resultSet.next()) {
count = resultSet.getLong(1);
}
resultSet.close();
statement.close();
connection.close();
return count;
}
/**
* 根据ID删除对应的数据
*
* @param id
* @throws ClassNotFoundException
* @throws SQLException
*/
public void deleteById(int id) throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///user-test?useSSL=false", "root", "123456");
PreparedStatement statement = connection.prepareStatement("delete from user where id=?");
statement.setObject(1, id);
int i = statement.executeUpdate();
statement.close();
connection.close();
}
/**
* 增加新用户
* @param user
* @throws ClassNotFoundException
* @throws SQLException
*/
public void insert(User user) throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///user-test?useSSL=false", "root", "123456");
PreparedStatement statement = connection.prepareStatement("insert into user(true_name,login_name,login_password,role,create_time)"+" values (?,?,?,?,now())");
statement.setObject(1, user.getTrueName());
statement.setObject(2, user.getLoginName());
statement.setObject(3, user.getLoginPassword());
statement.setObject(4, user.getRole());
int i = statement.executeUpdate();
statement.close();
connection.close();
}
/**
* 根据ID查找用户
* @param id
* @return
* @throws ClassNotFoundException
* @throws SQLException
*/
public User findById(int id) throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///user-test?useSSL=false", "root", "123456");
PreparedStatement statement = connection.prepareStatement("select * from user where id=?");
statement.setObject(1,id);
ResultSet resultSet = statement.executeQuery();
User user=null;
if (resultSet.next()) {
user = new User();
user.setId(id);
user.setTrueName(resultSet.getString("true_name"));
user.setLoginName(resultSet.getString("login_name"));
user.setLoginPassword(resultSet.getString("login_password"));
user.setRole(resultSet.getInt("role"));
user.setCreateTime(resultSet.getTimestamp("create_time"));
user.setUpdateTime(resultSet.getTimestamp("update_time"));
}
resultSet.close();
statement.close();
connection.close();
return user;
}
/**
* 修改用户信息
* @param user
* @throws ClassNotFoundException
* @throws SQLException
*/
public void update(User user) throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///user-test?useSSL=false", "root", "123456");
PreparedStatement statement = connection.prepareStatement("update user set true_name=?,login_name=?,login_password=?,role=?,update_time=now()"+" where id=?");
statement.setObject(1, user.getTrueName());
statement.setObject(2, user.getLoginName());
statement.setObject(3, user.getLoginPassword());
statement.setObject(4, user.getRole());
statement.setObject(5, user.getId());
int i = statement.executeUpdate();
statement.close();
connection.close();
}
}
④ CodeFilter类
package com.allen.filter;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebFilter("/*")
public class CodeFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) servletRequest;
HttpServletResponse respons= (HttpServletResponse) servletResponse;
request.setCharacterEncoding("UTF-8");
respons.setCharacterEncoding("UTF-8");
filterChain.doFilter(request,respons);
}
@Override
public void destroy() {
}
}
⑤ UserService 类
package com.allen.service;
import com.allen.dao.UserDao;
import com.allen.entity.User;
import com.allen.entity.ao.Page;
import java.sql.SQLException;
import java.util.List;
public class UserService {
UserDao userDao = new UserDao();
public Page<User> page(Page<User> page, String name) throws SQLException, ClassNotFoundException {
int size = page.getSize();
List<User> list = userDao.find(page.getPage(), size, name);
page.setList(list);
long count = userDao.count(name);
page.setCount(count);
page.setPageCount((int)((count%size==0)?(count/size):((count/size)+1)));
return page;
}
public void delete(int id) throws SQLException, ClassNotFoundException {
userDao.deleteById(id);
}
public void keep(User user) throws SQLException, ClassNotFoundException {
if(user.getId()!=null){
userDao.update(user);
}else{
userDao.insert(user);
}
}
public User findById(int id) throws SQLException, ClassNotFoundException {
return userDao.findById(id);
}
}
⑥ IndexServlet 类
package com.allen.servlet;
import com.allen.entity.User;
import com.allen.entity.ao.Page;
import com.allen.service.UserService;
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("/index")
public class IndexServlet extends HttpServlet {
UserService userService = new UserService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
request.setCharacterEncoding("UTF-8");
Page<User> pageAo = new Page<>();
String page = request.getParameter("page");
if (page!=null && page!="") {
pageAo.setPage(Integer.parseInt(page));
}
String size = request.getParameter("size");
if (size!=null && size!="") {
pageAo.setSize(Integer.parseInt(size));
}
Page<User> userPage = userService.page(pageAo, request.getParameter("name"));
request.setAttribute("userPage",userPage);
request.getRequestDispatcher("/WEB-INF/jsp/index.jsp").forward(request,response);
}catch (Exception e){
e.printStackTrace();
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
}
⑦ UserDeleteServlet 类
package com.allen.servlet;
import com.allen.service.UserService;
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("/userDelete")
public class UserDeleteServlet extends HttpServlet {
UserService userService = new UserService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
String id = request.getParameter("id");
if (id!=null && id!="") {
userService.delete(Integer.parseInt(id));
}
response.sendRedirect("index");
}catch (Exception e){
e.printStackTrace();
}
}
}
⑧ UserEditServlet 类
package com.allen.servlet;
import com.allen.entity.User;
import com.allen.service.UserService;
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("/userEdit")
public class UserEditServlet extends HttpServlet {
private UserService userService = new UserService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
String id = request.getParameter("id");
if (id!=null && id!="") {
User user = userService.findById(Integer.parseInt(id));
request.setAttribute("user",user);
}
request.getRequestDispatcher("/WEB-INF/jsp/edit.jsp").forward(request,response);
}catch(Exception e){
e.printStackTrace();
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
String loginName = request.getParameter("loginName");
String loginPassword = request.getParameter("loginPassword");
String role = request.getParameter("role");
String trueName = request.getParameter("trueName");
String id = request.getParameter("id");
User user = new User();
user.setLoginName(loginName);
user.setLoginPassword(loginPassword);
user.setRole(Integer.parseInt(role));
user.setTrueName(trueName);
if (id!=null && id!="") {
user.setId(Integer.parseInt(id));
}
userService.keep(user);
response.sendRedirect(request.getContextPath()+"/index");
}catch (Exception e){
e.printStackTrace();
}
}
}
⑨ edit.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Titletitle>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
head>
<body>
<div class="container">
<div class="row">
<div class="col-xs-12">
<h1 class="text-center">用户编辑h1>
<form class="form-horizontal" method="post">
<div class="form-group">
<label for="inputEmail3" class="col-sm-2 control-label">登录名label>
<div class="col-sm-10">
<input type="text" name="loginName" class="form-control" id="inputEmail3" placeholder="登录名" value="${user.loginName}">
div>
div>
<div class="form-group">
<label for="inputPassword3" class="col-sm-2 control-label">密码label>
<div class="col-sm-10">
<input type="text" name="loginPassword" class="form-control" id="inputPassword3" placeholder="密码" value="${user.loginPassword}">
div>
div>
<div class="form-group">
<label for="inputTrueName" class="col-sm-2 control-label">姓名label>
<div class="col-sm-10">
<input type="text" name="trueName" class="form-control" id="inputTrueName" placeholder="姓名" value="${user.trueName}">
div>
div>
<div class="form-group">
<label for="inputRole" class="col-sm-2 control-label">角色label>
<div class="col-sm-10">
<select name="role" class="form-control" id="inputRole" placeholder="角色" >
⑩ index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>用户管理title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
head>
<body>
<div class="container">
<div class="row">
<div class="col-xs-12"><h1>用户管理h1>div>
<div class="col-xs-9">
<a href="${pageContext.request.contextPath}/userEdit" class="btn btn-success">用户添加a>
div>
<div class="col-xs-3">
<div class="input-group">
<input type="text" class="form-control" placeholder="请输入姓名" id="name" value="${param.name}" }>
<span class="input-group-addon" onclick="findByName()">搜索span>
div>
div>
<div class="col-xs-12">
<table class="table">
<thead>
<tr>
<th>IDth>
<th>姓名th>
<th>登录名th>
<th>密码th>
<th>角色th>
<th>创建时间th>
<th>修改时间th>
<th>编辑th>
tr>
thead>
<tbody>
<c:forEach items="${userPage.list}" var="u">
<tr>
<td>${u.id}td>
<td>${u.trueName}td>
<td>${u.loginName}td>
<td>${u.loginPassword}td>
<td>${u.role==1?"超级管理员":u.role==2?"普通用户":u.role==3?"用户管理员":""}td>
<td>${u.createTime}td>
<td>${u.updateTime}td>
<td>
<a href="${pageContext.request.contextPath}/userDelete?id=${u.id}" class="btn btn-danger btn-sm">删除a>
<a href="${pageContext.request.contextPath}/userEdit?id=${u.id}" class="btn btn-info btn-sm">修改a>
td>
tr>
c:forEach>
tbody>
table>
<%-- ${userPage.pageCount}--%>
<%-- &name=${param.name}信息回显并查询列表--%>
<nav aria-label="Page navigation">
<ul class="pagination">
<li>
<a href="?page=${userPage.page>1?(userPage.page-1):1}&name=${param.name}" aria-label="Previous">
<span aria-hidden="true">上一页span>
a>
li>
<c:forEach begin="1" end="${userPage.pageCount}" var="u">
<li class="${u==userPage.page?"active":""}"><a href="?page=${u}&name=${param.name}">${u}a>li>
c:forEach>
<li>
<a href="?page=${userPage.page"
aria-label="Next">
<span aria-hidden="true">下一页span>(${userPage.count})
a>
li>
ul>
nav>
div>
div>
div>
<script>
function findByName() {
let name = document.getElementById("name").value;
location.href="?name="+name;
}
script>
body>
html>
⑩① web.xml
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<welcome-file-list>
<welcome-file>indexwelcome-file>
welcome-file-list>
web-app>
⑩② pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0modelVersion>
<groupId>com.examplegroupId>
<artifactId>user-testartifactId>
<version>1.0-SNAPSHOTversion>
<name>user-testname>
<packaging>warpackaging>
<properties>
<maven.compiler.target>1.8maven.compiler.target>
<maven.compiler.source>1.8maven.compiler.source>
<junit.version>5.7.1junit.version>
properties>
<dependencies>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>4.0.1version>
<scope>providedscope>
dependency>
<dependency>
<groupId>org.junit.jupitergroupId>
<artifactId>junit-jupiter-apiartifactId>
<version>${junit.version}version>
<scope>testscope>
dependency>
<dependency>
<groupId>org.junit.jupitergroupId>
<artifactId>junit-jupiter-engineartifactId>
<version>${junit.version}version>
<scope>testscope>
dependency>
dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-war-pluginartifactId>
<version>3.3.1version>
plugin>
plugins>
build>
project>
三、效果截图
用户添加如下：
用户修改如下：
用户修改成功如下：
数据分页如下：
模糊查询结果如下：
