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
文章图片
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 {
private List list;
private long count;
private int pageCount;
private int page=1;
private int size=10;
public List getList() {
return list;
}public void setList(List 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 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 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 page(Page page, String name) throws SQLException, ClassNotFoundException {
int size = page.getSize();
List 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 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 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
Title
用户编辑
⑩ index.jsp
用户管理
>
function findByName() {
let name = document.getElementById("name").value;
location.href="https://www.it610.com/article/?name="+name;
}
⑩① web.xml
index
⑩② pom.xml
4.0.0 com.example
user-test
1.0-SNAPSHOT
user-test
war1.8
1.8
5.7.1
javax.servlet
javax.servlet-api
4.0.1
>provided
org.junit.jupiter
junit-jupiter-api
${junit.version}
>test
org.junit.jupiter
junit-jupiter-engine
${junit.version}
>test
org.apache.maven.plugins
maven-war-plugin
3.3.1
三、效果截图
文章图片
??用户添加如下：
文章图片
??用户修改如下：
【Software|简单的增删改查及数据分页】
文章图片
??用户修改成功如下：
文章图片
??数据分页如下：
文章图片
??模糊查询结果如下：
文章图片
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