java web简单的注册登录界面实现(servlet+mysql+jsp+idea)_在idea中编写美化登陆注册页面的代码,并用servlet-jsp技术实现页面跳转

首先写一个实体类

package pojo;
 
public class U {
    private String username;
    private String password;
 
    public String getUsername() {
        return username;
    }
 
    public void setUsername(String username) {
        this.username = username;
    }
 
    public String getPassword() {
        return password;
    }
 
    public void setPassword(String password) {
        this.password = password;
    }
 
    @Override
    public String toString() {
        return "U{" +
                "username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

这段代码是用来对实体类进行数据的封装

下面在写一个数据库的连接类，包括了查询和更新的封装代码

package utils;
 
 
 
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.sql.*;
import java.util.HashMap;
import java.util.Map;
 
 
public class connectionUtils {
    private static String username ="admin";
    private static String password ="DEFdef123!";
    private static String url="jdbc:mysql://localhost:3306/db1";
    private static String driver="com.mysql.jdbc.Driver";
    private static Connection conn  ;
    private static Statement ts ;
    private static ResultSet  rs;
   static{
       try {
           Class.forName(driver);
       } catch (ClassNotFoundException e) {
           e.printStackTrace();
       }
   }
 
 
    //封装连接
    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(url,username,password);
    }
    //封装流的关闭
    public static void jdbcClose(ResultSet rs,Statement ts,Connection conn) throws SQLException {
        try{
            rs.close();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        finally {
            if(rs!=null){
                rs=null;
            }
        }
        ts.close();
        if(ts!=null){
            ts=null;
        }
        conn.close();
        if(conn!=null){
            conn=null;
        }
    }
    //更新封装
    public static int update(String sql,Object...argv) throws SQLException {
        //定义一个变量Prepared