1.首先下載合適的驅(qū)動包，8版本所用驅(qū)動jar包和5版本有出入，下載8版本地址如下：

鏈接：https://pan.baidu.com/s/1YJudxw01tG9PGBVxMZntkg
提取碼：jbml

2.在eclipse 新建(java工程)java project，并導入第一步下載的jar包，新建一個類如JdbcDemo如圖：

image.png

3.編寫JdbcDemo 程序

具體實現(xiàn)步驟如下：

1. 注冊驅(qū)動
   Class.forName("com.mysql.cj.jdbc.Driver").newInstance();

2.創(chuàng)建和數(shù)據(jù)庫的連接對象：是Connection接口的實現(xiàn)類對象
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/testJdbc?" + "user=root&password=123456&useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false");
3.獲取Sql語句的執(zhí)行者對象，是Statement接口的實現(xiàn)類對象
Statement stmt = conn.createStatement();
4.獲取結(jié)果集對象，是ResultSet接口的實現(xiàn)類對象
ResultSet rs = stmt.executeQuery("select* from user");
5.處理結(jié)果集

while (rs.next()) {
  Object id = rs.getObject("id");
  Object username = rs.getObject("username");
  System.out.println(id+"==="+username);
}

6.釋放資源

rs.close();
stmt.close();
conn.close();

整個示例代碼如下：

package com.liquan;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JdbcDemo {
    public static void main(String[] args){
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
         try {
            Class.forName("com.mysql.cj.jdbc.Driver").newInstance();
             conn =
                       DriverManager.getConnection("jdbc:mysql://localhost/testJdbc?" +
                                                   "user=root&password=123456&useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false");
             stmt = conn.createStatement();
                rs = stmt.executeQuery("SELECT * FROM user");
                while(rs.next()){
                      Object id = rs.getObject("id");
                              Object username = rs.getObject("username");
                              System.out.println(id+"==="+username);
                    }

        } catch (InstantiationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            // it is a good idea to release
            // resources in a finally{} block
            // in reverse-order of their creation
            // if they are no-longer needed

            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException sqlEx) { } // ignore

                rs = null;
            }

            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException sqlEx) { } // ignore

                stmt = null;
            }
        }
    }
}

ps: 使用的過程中可能會出現(xiàn)連接錯誤等，有可能的原因是mysql8默認開啟了安全認證，或者是因為時區(qū)的原因造成的，因此創(chuàng)建連接的時候可以制定一些連接參數(shù)如：
useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false