哪个网站做香烟回收关键词热度

一、系统介绍

该系统实现了管理员系统登陆、用户信息查询、用户信息添加、用户信息修改、用户信息删除。

二、功能展示

1.管理员登陆

2.用户信息查询

3.用户信息添加

4.用户信息修改

5.用户信息删除

三、系统实现

1.UserDao .java

package dao;import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import entity.User;
import util.DbUtils;public class UserDao {private Connection conn=null;private PreparedStatement ps=null;private ResultSet rs=null;//登陆public boolean login(String username,String password){String sql="select * from t_user where username='"+ username +"' and password='"+password+"'";List<User> list=new ArrayList<User>();boolean istrue = false;try {conn=DbUtils.getConnection();ps=conn.prepareStatement(sql);rs=ps.executeQuery();System.out.println(ps.toString());while(rs.next()){istrue=true;}DbUtils.close(rs, ps, conn);          } catch (SQLException e) {e.printStackTrace();}return istrue;}//查询用户信息public ArrayList<User> selectUser(String username) {ArrayList<User> tag_Array = new ArrayList<User>();Connection conn = null;try {conn = DbUtils.getConnection();} catch (SQLException e1) {// TODO Auto-generated catch blocke1.printStackTrace();};String sql = "select * from t_user where username like '%"+ username +"%'";PreparedStatement stm = null;ResultSet rs = null;try {stm = conn.prepareStatement(sql);rs = stm.executeQuery();while(rs.next()){User user = new User();user.setUuid(rs.getString("uuid"));user.setUsername(rs.getString("username"));user.setPassword(rs.getString("password"));tag_Array.add(user);}			} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{try {DbUtils.close(rs, stm, conn);} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}return tag_Array;}//添加用户信息public int addUser(String uuid,String username,String password){int result=0;String sql="insert into t_user(uuid,username,password) values(?,?,?)";try {conn=DbUtils.getConnection();ps = conn.prepareStatement(sql);ps.setString(1, uuid);ps.setString(2, username);ps.setString(3, password);result =ps.executeUpdate();// 返回值代表收到影响的行数DbUtils.close(rs, ps, conn);          } catch (SQLException e) {e.printStackTrace();}return result;}//修改用户信息public int updateUser(String uuid,String username,String password){int result=0;String sql="update t_user set username=?,password=? where uuid =?";try {conn=DbUtils.getConnection();ps = conn.prepareStatement(sql);          ps.setString(1, username);ps.setString(2, password);ps.setString(3, uuid);result =ps.executeUpdate();// 返回值代表收到影响的行数DbUtils.close(rs, ps, conn);          } catch (SQLException e) {e.printStackTrace();}return result;}//删除public int DelUser(String uuid){int result=0;String sql="DELETE from t_user where uuid = '" + uuid + "'";try {conn=DbUtils.getConnection();ps = conn.prepareStatement(sql);result =ps.executeUpdate();// 返回值代表收到影响的行数DbUtils.close(rs, ps, conn);          } catch (SQLException e) {e.printStackTrace();}return result;}
}

四、其它

1.其他系统实现

Java+Swing实现学生选课管理系统
Java+Swing图书管理系统