jdbc mysql statement_类型不匹配：java.sql.Statement无法转换为java.beans.Statement

主要原因是导包时大意，导错包，很难发现问题。为简便，可先直接导所有包

import java.sql.*;

package com.zf.jdbc.utils;

import  java.sql.Statement;//导包导错
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
//import java.sql.*;
//JDBC工具类
//提取出经常用的代码段，简化代码
public class DBCutils {
//    简化代码，方便灵活使用
    private static final String driverClassName;
    private static final String url;
    private static final String username;
    private static final String password;
    static {
        driverClassName="com.mysql.cj.jdbc.Driver";
        url="jdbc:mysql:///web_test3";
        username="root";
        password="123456";
    }
//    -----------------------------------------------------------------------------------

    //注册驱动的方法
    public static void loadDriver(){
        try {
            Class.forName(driverClassName);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

    }
//    -----------------------------------------------------------------------------------
//    获得连接的方法
    public static Connection getConnection(){
        //将驱动一并注册，只需调用这一个
        Connection conn = null;
        try {
            loadDriver();
            //获得链接
            conn = DriverManager.getConnection(url, username, password);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
//    ------------------------------------------------------------------------------------------
//    资源的释放 查询需要3个，增删改需要2个 写重载方法
    public static void release(Statement stmt,Connection conn){
        if (stmt!=null){
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            stmt=null; //手动置为空
        }
        if (conn!=null){
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            conn=null;
        }
    }
    public static void release(ResultSet rs,Statement stmt, Connection conn){
        if (rs!=null){
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            rs=null; //手动置为空
        }
        if (stmt!=null){
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            stmt=null; //手动置为空
        }
        if (conn!=null){
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            conn=null;
        }
    }


}

测试工具类

package com.zf.jdbc.utils;

import java.sql.Connection;// 刚开始导包错误，
import java.sql.ResultSet;
import java.sql.Statement;
//import java.sql.*;
public class Utilstest {
public static void main(String[] args) {


        Connection conn=null;
        Statement stmt=null;
        ResultSet rs=null;
        try {
conn=DBCutils.getConnection();
stmt=conn.createStatement();
String sql="select * from user";
rs=stmt.executeQuery(sql);
while (rs.next()){
    System.out.println(rs.getInt("id")+" "+rs.getString("username")+" "+rs.getString("password")+" "+rs.getString("nickname")+" "+rs.getInt("age"));
}
        }catch (Exception e){
            e.printStackTrace();
        }finally {
DBCutils.release(rs,stmt,conn);
        }
    }
}